CSS3小方块跳动

方块跳动
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>跳动</title>
    <style>
        .box:before {
            content: '';
            position: absolute;
            z-index: 2;
            top: 60px;
            left: 50px;
             50px;
            height: 50px;
            background: #c00;
            border-radius: 2px;
            transform: rotate(45deg);
            -webkit-animation: box .8s infinite;
        }

        @-webkit-keyframes box {
            0% {
                top: 50px;
                transform: rotate(90deg);
            }
            20% {
                border-radius: 2px; /*从20%的地方才开始变形*/
            }
            50% {
                top: 80px;
                transform: rotate(45deg);
                border-bottom-right-radius: 25px;
            }
            80% {
                border-radius: 2px; /*到80%的地方恢复原状*/
            }
            100% {
                top: 50px;
                transform: rotate(0deg);
            }
        }

        .box:after {
            content: '';
            position: absolute;
            z-index: 1;
            top: 128px;
            left: 52px;
             44px;
            height: 3px;
            background: #eaeaea;
            border-radius: 100%;
            -webkit-animation: shadow .8s infinite;
        }

        @-webkit-keyframes shadow {
            0%, 100% {
                left: 54px;
                 40px;
                background: #eaeaea;
            }
            50% {
                top: 126px;
                left: 50px; /*让阴影保持在原位*/
                 50px;
                height: 7px;
                background: #eee;
            }
        }


    </style>
</head>
<body>

    <div class="box"></div>

</body>
</html>