index.html

<!DOCTYPE html>
<html>
  <head>
    <title>Flip Effect Example</title>
    <link rel="stylesheet" type="text/css" href="styles.css" />
    <style>
      .block {
        width: 200px;
        height: 200px;
        perspective: 800px;
        position: relative;
        transform-style: preserve-3d;
        transition: transform 0.5s;
      }

      .block:hover {
        transform: rotateY(180deg);
      }

      .block__face {
        position: absolute;
        width: 100%;
        height: 100%;
        backface-visibility: hidden;
      }

      .block__front {
        background-color: #f2f2f2;
      }

      .block__back {
        transform: rotateY(180deg);
        background-color: #ddd;
      }

      /* Optional styling */
      .block__front,
      .block__back {
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 24px;
        color: white;
        font-weight: bold;
      }
    </style>
  </head>
  <body>
    <div class="block">
      <div class="block__face block__front">
        <h1>Front Face</h1>
      </div>
      <div class="block__face block__back">
        <h1>Back Face</h1>
      </div>
    </div>
  </body>
</html>