按钮放大动画效果

    <style type="text/css">
        .clicksign {
            display: block;
            position: absolute;
            left: 0;
            top: 0;
            border-radius: 50%;
            opacity: .8;
            background: red;
            background-size: 100%;
            -webkit-animation: scaleSize 1s linear infinite alternate;
            -o-animation: scaleSize 1s linear infinite alternate;
            animation: scaleSize .5s linear infinite alternate;
        }
        @keyframes scaleSize {
            0% {
                width: 40px;
                height: 40px;
                transform: translate(0);
            }
            100% {
                width: 30px;
                height: 30px;
                -webkit-transform: translateY(4px);
                -moz-transform: translateY(4px);
                -ms-transform: translateY(4px);
                -o-transform: translateY(4px);
                transform: translateY(4px);
                font-size: 30px;
            }
        }
    </style>