Animation动画animation动画......................................

alternate 偶数次逆向执行
infinite 永远执行
forwards 停止在最后结束状态

开始帧和结束帧动画

盒子大小由0倍变为2倍，偶数次逆向执行，永远执行

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            margin: 100px auto;
            width: 200px;
            height: 200px;
            background-color: orange;
            animation: bigger 1s linear 0s alternate infinite;
        }

        @keyframes bigger {
            from {
                transform: scale(0);
            }

            to {
                transform: scale(2);
            }
        }
    </style>
</head>

<body>
    <div></div>
</body>

</html>

多关键帧动画

盒子的颜色在不同关键帧都拥有各自的颜色，匀速变色停止在最后结束状态（红色）

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            margin: 100px auto;
            width: 200px;
            height: 200px;
            background-color: orange;
            animation: changeColor 3s linear 0s forwards;
        }

        @keyframes changeColor {
            0% {
                background-color: orange;
            }

            20% {
                background-color: yellow;
            }

            40% {
                background-color: blue;
            }

            60% {
                background-color: green;
            }

            80% {
                background-color: purple;
            }

            100% {
                background-color: red;
            }
        }
    </style>
</head>

<body>
    <div></div>
</body>

</html>