*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    background:#fff;
    padding:30px 0;
}
/* 洋红色外层容器 画布比例匹配截图 1920宽 960高 */
.magenta-wrap{
    width: 1920px;
    height: 960px;
    margin:0 auto;
    position: relative;
    overflow: hidden;
    background:#d80086;
}
/* 可上传底层背景图 */
.bg-layer{
    width:100%;
    height:100%;
    position:absolute;
    top:0;
    left:0;
    z-index:1;
    object-fit:cover;
}
/* 5个视频整体容器：底部距底边60px，左右边距156px */
.video-group{
    position:absolute;
    bottom:60px;
    left:156px;
    right:156px;
    display:flex;
    justify-content:space-between;
    z-index:10;
}
/* 单个视频框 竖版16:9 计算比例：宽16 高9 竖版反过来 宽9 高16 */
.video-card{
    width:18.4%;
    aspect-ratio:9 / 16;
    background:#fff200;
    overflow:hidden;
}
.video-card video{
    width:100%;
    height:100%;
    display:block;
    object-fit:cover;
    muted:true;
}
/* 上传背景按钮 */
#uploadBg{
    position:absolute;
    top:15px;
    left:15px;
    z-index:99;
    padding:8px 16px;
    background:rgba(0,0,0,0.35);
    color:#fff;
    border:none;
    border-radius:4px;
    cursor:pointer;
}