*{
    margin: 0;
    padding: 0;
    background-color: transparent;
}
a{
    text-decoration: none;
}
img {
    vertical-align: middle;
    border: none;
}
ul{
    /* list-style: none; */
}
#main{
    height: calc(100vh - 48px);
}
#main .sider{
    width: 340px;
    height: 100%;
    border-right: 1px solid #e8e8e8;
    overflow-x: hidden;
    box-sizing: content-box;
    background-color: #fff;
    overflow-y: auto;
}
#main .f-left{
    float: left;
}
#main .sider-inner{
    width: 340px;
}
.catelog{
    padding: 0 8px;
    color: #31285d;
}
.catelog-title{
    padding: 15px 0;
    font-size: 16px;
    text-align: center;
}
.catelog-title > a {
    display: inline-block;
    color: #31285d;
}
.catelog-title span {
    display: inline-block;
    vertical-align: middle;
}
.catelog-title span.img {
    height: 48px;
    margin: 0 7px;
    border-radius: 4px;
    overflow: hidden;
}
.catelog-title span.word {
    margin: 7px 0;
}
.catelog-list{
    /* padding-bottom: 53px; */
}
.catelog-list > .chapter-item{
    padding-bottom: 24px;
}
.catelog-list .chapter-title{
    position: relative;
    height: 42px;
    margin-bottom: 8px;
    padding: 0 40px 0 12px;
    border-radius: 4px;
    line-height: 42px;
    font-size: 15px;
    font-weight: 600;
    background-color: #dbe7f9;
    cursor: pointer;
}
.single-ellipsis {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.catelog-list .chapter-list{
    overflow: hidden;
    display: block;
    padding: 0 8px; 
}
.chapter-list ul li{
    line-height: 48px;
    border: 1px solid transparent;
    padding: 0 2px;
}
.chapter-list ul li >a{
    position: relative;
    display: block;
    font-size: 14px;    
    color: #31285d;
    border-bottom: 1px dashed #ddd;
}
.chapter-list ul li >a:hover{
    background-color: #eee;
    border-radius: 5px;
}
.learning{
    padding-right: 70px;
}
/* .chapter-list li > a > .word{
    margin-left: 8px;
} */
.chapter-list li .learning-tip{
    color: #50CCCC;
    position: absolute;
    top: 0;
    right: 0;
}
/* 滚动条优化 */
.scrollbar::-webkit-scrollbar{
    width: 8px;
    height: 10px;
}
.scrollbar::-webkit-scrollbar-track{
    border-radius:8px;
}
.scrollbar::-webkit-scrollbar-thumb{
    border-radius:8px;
    background-color: #ccc;
}


/* 中间内容区 */
#main .content{
    height: calc(100% - 30px);
    overflow-x: hidden;
}
.content .play-area{
    box-sizing: content-box;
    max-width: 960px;
    margin: 0 auto;
    padding: 20px 36px;
}
.content .play-card{
    padding-top: 0;
    background-color: #fff;
    box-shadow: 0 1px 3px 1px #d9dfe9;
}
.play-card .play-card-head{
    position: relative;
    background-color: #b5d1fa;
    text-align: center;
    line-height: 45px;
    border-radius: 4px 4px 0 0;
    height:45px;
}
.play-card .play-card-list{
    display: inline-block;
    padding: 0 100px;
    vertical-align: bottom;
}
.play-card .play-card-list li{
    float: left;
}
.play-card .play-card-list li img{
    padding-bottom: 5px;
}
.play-card .play-card-list >li{
    width: 45px;
    height: 45px;
    margin-right: 10px;
    font-size: 24px;
    color: #fff;
    cursor: pointer;
}
.play-card .play-card-list >li.active{
    background-color: #f9fafd;
    color: #675f8f;
}
.play-card-nums{
    position: absolute;
    top: 0;
    right: 0;
    padding: 0 25px;
    font-size: 20px;
    color: #31285d;
}
.play-card-nums .separator{
    margin: 0 2px;
}
.play-card .play-card-body{
    padding: 20px 30px 25px;
    overflow: hidden;
    min-height: 400px;
}
/* .play-card-body .b-title{
    padding-bottom: 10px;
    border-bottom: 1px solid #ddd;
} */
.play-card-body .b-title .content-title{
    font-size: 20px;
    color: #333;
}
.play-card-body .b-content{
    margin-top: 15px;
    font-size: 15px;
    color: #333;
}

.play-area .play-btn{
    margin-top: 20px;
    float: right;
}
.play-area .play-btn > button{
    cursor: pointer;
}
.qcontent{
    padding: 0;
    font-size: 15px;
}
.qcontent p{
    word-wrap: break-word;
    margin: 0 0 5px;
    color: #333;
    line-height: 1.7;
}
.exam-item{
    padding: 15px 20px;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin-bottom: 15px;
    cursor: pointer;
}

/* 页脚区 */
#footer {
    display: flex;
    height: 55px;
    background-color: #f9f9f9;
    border-top: 1px solid #ddd;
    color: #31285d;
    font-size: 15px;
    position: absolute;
    bottom: 0;
    width: 100%;
}
#footer .catelog-switch{
    box-sizing: border-box;
    padding: 0 32px;
    line-height: 54px;
}
#footer .catelog-switch .switch-btn{
    cursor: pointer;
}
#footer .catelog-switch .switch-word{
    padding-left: 10px;
}
#footer .nav{
    width: 340px;
    margin: 0 auto;
    user-select: none;
    text-align: center;
} 
#footer > .nav > .nav-box >div{
    display: inline-block;
    line-height: 54px;
}
.nav-box .nav-prev{
    float: left;
    cursor: pointer;
}
.nav-box .nav-next{
   float: right;
   cursor: pointer;
}
#footer .user-active{
    padding: 0 32px;
    line-height: 54px;
    float: right;
}
#footer .user-active .cell{
    float: left;
}
#footer .user-active a > .word{
    margin-left: 4px;
    font-size: 15px;
}
#footer > .user-active > .cell {
    margin-left: 32px;
}
.idown{
    position: absolute;
    top: 13px;
    right: 12px;
    font-size: 16px;
    content: url(../../img/course/bottom2.png);
    transition: transform .4s;
}
.itop{
    position: absolute;
    top: 13px;
    right: 12px;
    font-size: 16px;
    transform: rotate(180deg);
}