回答

其实也就三行代码:

animation: appear linear; animation-timeline: view(); animation-range: entry 0% cover 40%;

完整代码如下：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Animate On Scroll</title>
    <style>
        body {
            min-height: 200vh; /* 为了创造滚动效果 */
            padding: 20px;
            font-family: Arial, sans-serif;
        }

        .block {
            width: 300px;
            height: 200px;
            margin: 10px;
            background-color: #3498db;
            
            display: flex;
            justify-content: center;
            align-items: center;
            color: white;
            font-size: 24px;
          
           
        }

        @keyframes appear {
            from {
                opacity: 0;
                clip-path: inset(100% 100% 0 0);
            }
            to {
                opacity: 1;
                clip-path: inset(0 0 0 0);
            }
        }

        .block {
            animation: appear linear;
            animation-timeline: view();
            animation-range: entry 0% cover 40%;
        }
    </style>
</head>
<body>
    <h1>Animate On Scroll</h1>
    <div class="block">Scrolling Element</div>
    <div class="block">Another Element</div>
    <div class="block">One More Element</div>
     <div class="block">One More Element</div>
      <div class="block">One More Element</div>
       <div class="block">One More Element</div>
</body>
</html>