animation-direction 动画方向

实例代码

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS animation-direction 演示</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
        }
        
        h1 {
            color: #333;
            text-align: center;
        }
        
        .container {
            display: flex;
            flex-direction: column;
            gap: 30px;
            margin-top: 40px;
        }
        
        .demo-box {
            height: 60px;
            width: 60px;
            background-color: #4CAF50;
            border-radius: 4px;
            position: relative;
            margin-bottom: 10px;
        }
        
        .demo-label {
            font-weight: bold;
            margin-bottom: 5px;
        }
        
        .normal .demo-box {
            animation: slide 3s infinite normal;
        }
        
        .reverse .demo-box {
            animation: slide 3s infinite reverse;
        }
        
        .alternate .demo-box {
            animation: slide 3s infinite alternate;
        }
        
        .alternate-reverse .demo-box {
            animation: slide 3s infinite alternate-reverse;
        }
        
        @keyframes slide {
            from { transform: translateX(0); }
            to { transform: translateX(200px); }
        }
        
        .controls {
            margin-top: 30px;
            padding: 15px;
            background-color: #f5f5f5;
            border-radius: 4px;
        }
        
        button {
            padding: 8px 15px;
            margin-right: 10px;
            background-color: #4CAF50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }
        
        button:hover {
            background-color: #45a049;
        }
    </style>
</head>
<body>
    <h1>CSS animation-direction 演示</h1>
    
    <div class="container">
        <div class="demo normal">
            <div class="demo-label">normal (默认): 始终正向播放</div>
            <div class="demo-box"></div>
        </div>
        
        <div class="demo reverse">
            <div class="demo-label">reverse: 始终反向播放</div>
            <div class="demo-box"></div>
        </div>
        
        <div class="demo alternate">
            <div class="demo-label">alternate: 奇数次正向，偶数次反向</div>
            <div class="demo-box"></div>
        </div>
        
        <div class="demo alternate-reverse">
            <div class="demo-label">alternate-reverse: 奇数次反向，偶数次正向</div>
            <div class="demo-box"></div>
        </div>
    </div>
    
    <div class="controls">
        <p>你可以尝试修改动画持续时间：</p>
        <button onclick="changeDuration(1)">1秒</button>
        <button onclick="changeDuration(2)">2秒</button>
        <button onclick="changeDuration(3)">3秒</button>
        <button onclick="changeDuration(5)">5秒</button>
    </div>
    
    <script>
        function changeDuration(seconds) {
            const boxes = document.querySelectorAll('.demo-box');
            boxes.forEach(box => {
                box.style.animationDuration = `${seconds}s`;
            });
        }
    </script>
</body>
</html>