Hướng dẫn image overlay bootstrap 4 - bootstrap lớp phủ hình ảnh 4

Image Hover Overlay có thể hiểu sang tiếng việt là hình ảnh được che phủ khi hover, đúng với các tên của nó, Image Hover Overlay là các hình ảnh mà khi hover chuột lên nó, hình ảnh sẽ được che phủ bởi một đoạn text, một button hay một liên kết nào đó.

Nội dung chính Show

1. Xây dựng giao diện
2. Thêm CSS cho giao diện
3. Lời kết

Bài viết này được đăng tại freetuts.net, không được copy dưới mọi hình thức.freetuts.net, không được copy dưới mọi hình thức.

Trong bài viết này, chúng ta sẽ cùng nhau xây dựng một số Image Hover Overlay với các hiệu ứng khác nhau.

1. Xây dựng giao diện

Đầu tiên chúng ta sẽ xây dựng các thành phần, các bạn tạo file index.html và dán đoạn mã sau vào trong thẻ body:

Code

<div class="main">
  <h2>Freetuts.net hướng dẫn tạo Image Hover Overlay</h2>
  <p>Hover lên ảnh để xem hiệu ứng</p>
  <div class="container">
    <img src="./images/demo.jpg" alt="Avatar" class="image">
    <div class="overlay">
      <div class="text">Freetuts.net</div>
    </div>
  </div>
</div>

Trong ứng dụng này chúng ta sẽ có hai thành phần chính đó là phần hình ảnh và phần thẻ div, cái sẽ được hiện hiện đè lên hình ảnh khi hình ảnh được hover.

Bài viết này được đăng tại [free tuts .net]

OK giờ chuyển qua bước tiếp theo.

2. Thêm CSS cho giao diện

Chúng ta đã có thành phần hiển thị rồi giờ sử dụng CSS để định dạng cho chúng, các bạn đặt đoạn CSS dưới đây vào bên trong thẻ style:

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Đầu tiên, mình sẽ đặt thuộc tính opacity: 0; cho phần thẻ div, thuộc tính này sẽ khiến nó trở nên trong suốt và do đó hình ảnh sẽ được hiển thị.

Tiếp đến khi hình ảnh được hover, mình đặt lại opacity: 1; cho phần thẻ div này và nó sẽ được hiển thị đè lên phàn hình ảnh.

Chúng ta cũng có thể sử dụng đoạn mã CSS sau để thay thế cho đoạn CSS trên nếu bạn muốn một hiệu ứng khác khi hover vào hình ảnh:

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Khác với ở trên, lần này mình không sử dụng thuộc tính opacity nữa mà mình sẽ lợi dụng thuộc tính height và transition:

Mặc định, mình sẽ đặt height của phần thẻ div là 0 để ẩn nó đi.
Khi hình ảnh được hover, mình đặt lại height = 100% cho nó, do đã được thiết lập thuộc tính transition nên phần thẻ div sẽ có hiệu ứng chuyển động.

Dựa vào các thuộc tính của CSS, các bạn có thể tùy biến rất nhiều hiệu ứng, ở đây mình không thể trình bày hết được, giờ các bạn chạy file index.html để xem thành quả mình vừa tạo ra nhé!

3. Lời kết

Như vậy, qua bài viết này mình đã cùng các bạn tạo một Image Hover Overlay với CSS. Hi vọng nó sẽ giúp các có thêm sự lựa chọn trong quá trình xây dựng website, nếu có bất cứ thắc mắc nào các bạn có thể để lại trong phần bình luận, hẹn gặp lại trong các bài viết tiếp theo trên freetuts.net.

Tham khảo: w3schools.com

Trong bài viết này, chúng tôi sẽ học cách sử dụng lớp phủ hình ảnh một cách chính xác với Bootstrap. Nhưng trước đó, trước tiên, chúng ta cần biết lớp phủ hình ảnh là gì.

Lớp phủ hình ảnh: Lớp phủ hình ảnh thường đề cập đến hình ảnh là hình ảnh nền và chèn các văn bản và liên kết bên trong hình ảnh đó. Nó có thể được thực hiện bằng cách sử dụng thuộc tính ‘Card-Img-Overlay có mặt trong Bootstrap. Ngoài ra, chúng tôi có thể làm điều đó với CSS bình thường cùng với chủ đề bootstrap. Hôm nay chúng ta sẽ học cả hai kỹ thuật để hiểu tài sản. Image overlay generally refers to the image being a background image and inserting texts, and links inside of that image. It can be done using the ‘card-img-overlay’ property that is present in bootstrap. Also, we can do it with normal CSS along with a bootstrap theme. Today we will be learning both the techniques to understand the property.

Ví dụ 1: Sử dụng thuộc tính ‘Card-Img-Overlay trong Bootstrap. Using the ‘card-img-overlay’ property in bootstrap.

Lúc đầu, chúng tôi cần cdn bootstrap cần thiết để sử dụng các thành phần bootstrap. Để có được những thứ đó, người ta có thể chỉ cần truy cập trang web của họ và sao chép các liên kết vào mã của họ. Liên kết đến CDN được cung cấp dưới đây:

https://getbootstrap.com/docs/5.0/getting-started/introduction/

Từ đó, sao chép tất cả các tệp CSS và JS vào mã của bạn.

Code:

HTML

<!DOCTYPE html>

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9index.html0

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9index.html2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html6

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9index.html8

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 0;0

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 0;2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1opacity: 0;6

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 0;8

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 1;0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1opacity: 1;4

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 1;6

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

6height = 100%0

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

height = 100%0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0height = 100%7

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Các

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0index.html8

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Các

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0index.html1 index.html2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

16__

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

20 index.html2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

18height = 100%0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0index.html1 index.html2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

43 index.html2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

25height = 100%0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

18height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

03height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Các

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1height = 100%0index.html8

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

6height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

height = 100%0height = 100%7

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

height = 100%0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Output:

Trong đầu ra, văn bản và liên kết đang hoạt động đúng bên trong hình ảnh và do đó tính năng Lớp phủ hình ảnh được thể hiện.

Ví dụ 2: (chỉ sử dụng CSS mà không sử dụng lớp Bootstrap): Trong ví dụ này, chúng tôi sẽ trình diễn lớp phủ hình ảnh bằng CSS trong khi Bootstrap sẽ được đưa vào mã. Nhưng trước khi viết mã, chúng tôi phải bao gồm các cdns bootstrap để có được hiệu ứng bootstrap cho trang web của chúng tôi. (Using only CSS without using Bootstrap class): In this example, we will be demonstrating image overlay using CSS while bootstrap will be included in the code. But before writing the code, we must include the bootstrap CDNs in order to get the bootstrap effect to our website.

Code:

HTML

<!DOCTYPE html>

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
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  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
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  height: 100%;
}

.text {
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  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
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  right: 0;
  background-color: #888888;
  overflow: hidden;
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}

.container:hover .overlay {
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  height: 100%;
}

.text {
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  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
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}

.text {
  white-space: nowrap; 
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  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
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  width: 100%;
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  background-color: #888888;
}

.container:hover .overlay {
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}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
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  right: 0;
  height: 100%;
  width: 100%;
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  background-color: #888888;
}

.container:hover .overlay {
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}

.text {
  color: white;
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  position: absolute;
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  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
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}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
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  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
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  background-color: #888888;
}

.container:hover .overlay {
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}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
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}

.container:hover .overlay {
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}

.text {
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  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
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}
.container {
  position: relative;
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}

.image {
  display: block;
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}

.overlay {
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}

.container:hover .overlay {
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}

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}

.main {
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}
.container {
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}

.image {
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}

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}
.container {
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}

.image {
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}

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}

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}

.main {
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}
.container {
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}

.image {
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}

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}

.container:hover .overlay {
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}

.text {
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  overflow: hidden;
  top: 50%;
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  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
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  background-color: #888888;
  overflow: hidden;
  width: 100%;
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}

.container:hover .overlay {
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}

.text {
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  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
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  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 0;8

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
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  transition: .5s ease;
}

.container:hover .overlay {
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}

.text {
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  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
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  height: auto;
}

.overlay {
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  transition: .5s ease;
}

.container:hover .overlay {
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}

.text {
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  top: 50%;
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  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
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  height: auto;
}

.overlay {
  position: absolute;
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}

.container:hover .overlay {
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}

.text {
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  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
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}

.container:hover .overlay {
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}

.text {
  white-space: nowrap; 
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  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
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}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
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}

.text {
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  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
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  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
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}

.text {
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  overflow: hidden;
  top: 50%;
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  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
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}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9index.html2

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9opacity: 0;

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html6

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1index.html4

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

6height = 100%0

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

height = 100%0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0height = 100%7

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0index.html8

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

0<!DOCTYPE html>2<!DOCTYPE html>3<!DOCTYPE html>2

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Các

https://getbootstrap.com/docs/5.0/getting-started/introduction/

https://getbootstrap.com/docs/5.0/getting-started/introduction/

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Các

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

18height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

03height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

https://getbootstrap.com/docs/5.0/getting-started/introduction/

9height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  bottom: 100%;
  left: 0;
  right: 0;
  background-color: #888888;
  overflow: hidden;
  width: 100%;
  height:0;
  transition: .5s ease;
}

.container:hover .overlay {
  bottom: 0;
  height: 100%;
}

.text {
  white-space: nowrap; 
  color: white;
  font-size: 20px;
  position: absolute;
  overflow: hidden;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

1height = 100%0index.html1

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

6height = 100%0index.html8

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

height = 100%0height = 100%7

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

height = 100%0

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

.main {
  width: 500px;
  text-align: center;
  margin: auto;
}
.container {
  position: relative;
  width: 100%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #888888;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
}

Output:

HTML là nền tảng của các trang web và được sử dụng để phát triển trang web bằng cách cấu trúc các trang web và ứng dụng web.Bạn có thể tìm hiểu HTML từ đầu bằng cách làm theo các ví dụ HTML và HTML này.

CSS là nền tảng của các trang web và được sử dụng để phát triển trang web bằng cách tạo kiểu trang web và ứng dụng web.Bạn có thể học CSS từ đầu bằng cách làm theo các ví dụ về hướng dẫn CSS và CSS này.