#Download {
    width: 883px;
    height: 194px;
    text-align: center;
    position: absolute;
    top: 910px;
    left: 50%;
    margin-left: -430px;
    z-index: 51;
    border-radius: 5px;
    background: url() no-repeat left top;
}
#Download .btn_down_s1 {
    animation: sc 2s infinite linear;
    float: left;
    width: 345px;
    height: 97px;
    text-indent: -999em;
    background: url(../image/btn_down1.png) no-repeat left top;
}
#Download .btn_down_s2 {
    animation: sc 2s infinite linear;
    float: left;
    width: 345px;
    height: 97px;
    text-indent: -999em;
    margin-left: 180px;
    background: url(../image/btn_down2.png) no-repeat left top;
}
#Download .btn_down_s1:hover {
    background: url(../image/btn_down1.png) no-repeat left bottom;
}
#Download .btn_down_s2:hover {
    background: url(../image/btn_down2.png) no-repeat left bottom;
}
@keyframes sc {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(0.8);
    }

    100% {
        transform: scale(1);
    }
}