.vistop {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px;
    height: 50px;
    z-index: 5;
}

    .vistop img {
        width: 50px;
        height: 50px;
        opacity: 1;
    }
.studyList{
    font-size: 0;
    border-bottom: 1px solid #d8dbe0;
    padding: 30px 0 ;
    box-sizing: border-box;
}

.fastucate {
    float: left;
    width: 14%;
    padding: 10px 30px;
    text-align: center;
    color: #6b7586;
    font-size: 18px;
    box-sizing: border-box;
    border-radius: 18px;
    cursor: pointer;
}
.stucate{
   padding:  0 10px;
}

.stucateActive{
    background-color: #3f75fb;
    color: white;
}

/* 内容区域 */

.container{
    margin: 30px 0 ;
}

.stuleftside{
    float: left;
    width: 25%;
}
.sturightside{
    float: left;
    width: 75%;
}

/* 左侧tab */
.fastuleftitem{
    padding: 0px  50px 0 0px;
    position: relative;
    margin: 15px 0 ;
}
.bluebolck{
    position: absolute;
    top: 50%;
    left: 1px;
    width: 5px;
    height: 50px;
    background-color: #497cfb;
    transform: translateY(-50%);
    display: none;
}
.stuleftitem{
 
 background-color: #f2f6ff;
 padding-left: 30px;

}
.bok{
    float: left;
    padding-top: 28px;
    padding-right: 15px;
}
.stutitle{
    float: left;
    padding-top: 28px;
    font-size: 24px;
    
   
}
.stupic{
    float: right;
    display: none;
}
.stuActive{
    display: block!important;
}
.stuColorActive{
    color: #3f75fb;
}


/* 列表 */

.stuList{
    padding: 10px;
    box-sizing: border-box;
}

.fastuVideoItem{
    width: 33%;
    float: left;
    position: relative;
    margin: 10px 0 ;
    padding:0px 10px;
    box-sizing:border-box;
    
}

.stuVideoItem {
    border-radius:20px;
    overflow:hidden;
}
.stuVideoItem:hover .iteminfo {
    background-color: #dce3f3;
}
.stuplay{
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);
}
.stuplay img {
    width: 50px;
    height: 50px;
}
.stuVideoItem  .proinfo{transition: all 0.4s;}
.stuvideo{
    position: relative;
    overflow: hidden;
    height: 0;padding-top: 78.125%;box-sizing: content-box;
}
.stuvideo>img{position: absolute;left: 0;top: 0;width: 100%;height: 100%;object-fit: cover;}
.stuvideo1 {
    position: relative;
    overflow: hidden;
}
.stuvideo::before {
    content: ""; /* 必须有content属性，否则伪元素不会显示 */
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.2); /* 设置遮罩层的背景色和透明度 */
    z-index: 1; /* 确保遮罩层在元素之上 */
    /*border-radius: 20px;*/
}
    .stuvideo1::before {
        content: ""; /* 必须有content属性，否则伪元素不会显示 */
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
         /* 设置遮罩层的背景色和透明度 */
        z-index: 1; /* 确保遮罩层在元素之上 */
        border-radius: 20px;
    }
    .stuvideo img {
        object-fit: cover;
        transition: transform .6s linear;
    }

.iteminfo{
    padding: 10px 10px;
    background-color: #ebf1ff;
    box-sizing: border-box;
    transition: all 0.4s;
    border-radius:0px!important;
}
.itemtitle{
    font-size: 18px;
    color: #333333;
    white-space: nowrap;
    overflow: hidden;
    width: 100%;
    font-weight: 700;
    padding: 10px 0 ;
    text-overflow: ellipsis;
}
.itemsumy{
    color: #333333;
    font-size: 14px;
    line-height: 24px;
    height: 48px;
    text-overflow:ellipsis;
display:-webkit-box; 
-webkit-box-orient:vertical;
-webkit-line-clamp:2; 
overflow: hidden;
}

.ductleft{
    height: auto;
    background-color: transparent;
}
.ductclass{
    background-color:#ebf1ff;
    margin: 20px 0 ;
}
@media screen  and  (max-width:1200px){
    .fastucate{
        font-size: 20px;
        padding: 10px 0px;
    }
    .stupic {
        /* display: none; */
        margin: auto;
    }
    .bok{
        padding-right: 5px;
    }
    .stutitle {
        font-size: 18px;
        padding-top: 32px;
    }
    .bluebolck{
        height: 35px;
    }
    .sturightside {
        width: 100%;
    }
    
}

/* @media screen and (max-width:850px) {
    .fastuleftitem{
        padding: 0 20px 0px 0;
    }
    .stucate {
        padding: 0;
    }
    .stuleftitem{
        padding-left: 10px;
    }
    .bok {
        padding-top: 12px;
        
    }
    .stutitle {
        padding-top: 19px;
    }
} */

@media screen and (max-width:500px) {
    .studyList{
        white-space: nowrap;
        width: 100%;
        overflow: auto;
        padding: 10px 0 ;
    }
    .fastucate{
        float: none;
        display: inline-block;
       width: fit-content;
       padding: 10px;
       font-size: 12px;
    }

    .stuleftside{
        width: 100%;
    }
    .fastuleftitem{
        padding: 10px;
    }
    .sturightside{
        width: 100%;
    }
    .fastuVideoItem{
        width: 50%;
    }
    .stuVideoItem{
        padding: 5px;
    }
    .stuList{
        padding: 0;
    }
    .ductclass{
        margin: 0;
    }
    .ducttap{
        font-size: 12px;
    }
    .itemtitle{
        font-size: 14px;
    }
    .itemsumy{
        font-size: 12px;
    }
}