* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

img {
    display: block;
    width: 100%;
    height: auto;
    max-width: 100%;
    margin: 0 auto;
}

a,
a:link,
a:hover {
    text-decoration: none;
}

.content {
    margin: 0 auto;
    padding-bottom: 150px;
}
.block {
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
}
.block_1{
    height: 426px;
    background-image: url('../images/riben_01.jpg');

}
.block_2{
    height: 468px;
    background-image: url('../images/riben_02.jpg');
}
.block_3{
    height: 506px;
    background-image: url('../images/riben_03.jpg');
}
.bottom {
    width: 100%;
    height: 39px;
    margin: 0px auto;
    background: url("../images/pc_22.jpg") center no-repeat;
    overflow: hidden;
    margin-top: 242px;
}

.bottom a {
    display: block;
    width: 33%;
    height: 39px;
    float: left;
}