.index_page {
    width: 100%;
    height: 100vh;
    background: url('https://mooc-1300652413.cos.ap-nanjing.myqcloud.com/丝路学院背景图/home-bg-new.png') no-repeat center center / cover;
    position: relative;
}
.index_page > img {
    position: absolute;
    width: 26%;
    top: 160px;
    left: 50%;
    margin-left: -13%;
}
.index_page a {
    display: block;
    width: 200px;
    height: 50px;
    background: #D9AC5620;
    border-radius: 25px;
    text-align: center;
    line-height: 50px;
    font-size: 20px;
    color: #705521;
    position: absolute;
    bottom: 160px;
    left: 50%;
    margin-left: -100px;
    border: 1px solid #705521;
    transition: all .3s ease-in-out;
}
.index_page a:hover {
    background: #D9AC56;
    opacity: .8;
    transform: scale(1.1);
}

@media screen and (min-width: 2999px) {
    .index_page {
        width: 3840px;
        height: 2160px;
    }
}