.video-list{width:100%; margin:2% 0;}
.video-list li{ float:left; width:24.5%;background:#f5f5f5;margin: 0 0.25% 1% 0.25%;}
.video-list li .thumb{ 
    position: relative;
    width: 100%;
    padding-top: 56.25%;
    overflow: hidden;
}
.video-list li .thumb img{ 
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
    transition: all 0.6s ease;
}
.video-list li .thumb img.photo1{
    width: auto;
    *max-height: 100%;
}

.video-list li .item{ padding:5%;}
.video-list li .item h3{font-size:15px; color:#55504f;text-overflow: ellipsis;white-space: nowrap;overflow: hidden;}

/*鼠标hover效果*/
.video-list li:hover .thumb img {
}
.video-list li .thumb:after {
    display:none;
    content: "";
    position: absolute;
    left: 0px;
    top: 0px;
    width: 100%;
    height: 100%;
    z-index: 1;
    transition: all 0.3s;
    background:rgba(0, 0, 0, 0.2) url(../image/video.svg) no-repeat center -500px/40px;
}
.video-list li:hover .thumb:after {
    display:block;
    background:rgba(0, 0, 0, 0.3) url(../image/video.svg) no-repeat center center/40px;
}

/*以下代码是自适应样式*/

@media screen and (max-width:1320px){}

@media screen and (max-width:1178px){
.video-list li{width:49.5%;margin: 0 0.25% 1% 0.25%;}
}


@media screen and (max-width:800px){
.video-list li{width:99.5%;margin: 0 0.25% 1% 0.25%;}
.video-list li .thumb i img{width:15%;}
}