@media screen and (min-width: 1200px) {
    .chan-box {
        position: fixed;
        /* 卷去的头部可用 */
        top: 190px !important;
        left: 50%;
    }
}
@media (min-width: 1200px){
    .container, .container-sm, .container-md, .container-lg, .container-xl {
        max-width: 1140px;
    }
}
.section {
    max-width: 1140px;
    margin-top: 0;
    /* 导读书目列表页二年级类似底部边距 */
    margin-bottom: 30px;
}
.tab-content {
    max-width: 1140px;
    padding-bottom: 20px;
}
/* 导读书目二年级下面第三步图书样式start */
.detail .step-list .step-title .col-6 .item a img {
    width: 100% ;
}

.without-img {
    display: block;
    /*height: 120px;*/
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-image: url("../images/without-img.svg");
    background-size: 100%;
}
/* 导读书目二年级下面第三步图书样式end */