利用动画延迟（animation-delay）实现复杂动画


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    :root {
        --delay:0s;
    }
    .box{
        width:100px;
        height:100px;
        border-radius: 50%;
        background: red;
        animation: cartoon 5s linear var(--delay);
        animation-play-state: paused;
        animation-fill-mode: none;
    }
    @keyframes cartoon {
        25%{
           transform: translate(0);
        }
        25%{
            background:blue;
            transform: translate(600px) scale(0.3);
        }

        75%{
            background:green;
            transform: translate(900px) scale(0.9);
        }
        100%{
            transform: translate(1000px);
        }
    }
    </style>
   
</head>
<body>
    <div class="box"></div>
   <input type="range" name="hello" id="range" min="0" max="1"step="0.01">
</body>

</html>
<script>
    /**
     * 更新动画延迟时间以控制动画进度
     * @param {HTMLElement} element - 需要控制动画的元素
     * @param {number} value - 控制值，通常来源于input元素，范围从0到1
     * @param {string} duration - 动画持续时间，格式为"Xs"或"Xms"
     */
    function updateAnimationDelay(element, value) {
        const duration = getComputedStyle(element).animationDuration;
        const delayTime = `-${value * parseFloat(duration)}s`;
        element.style.setProperty('--delay', delayTime);
    }


    const range = document.querySelector('#range')
    const box = document.querySelector('.box')

    range.addEventListener('input', (event) => {
        const v = event.target.value
        updateAnimationDelay(box, v);
    });
    // 在代码加载时手动触发一次回调函数
    range.dispatchEvent(new Event('input'));

</script>