/*给图片过渡效果*/
img {
    transition: all 0.5s;
    -moz-transition: all 0.5s;
    /* Firefox 4 */
    -webkit-transition: all 0.5s;
    /* Safari 和 Chrome */
    -o-transition: all 0.5s;
    /* Opera */
    ;
}

.index {
    width: 400px;
    margin: 0 auto;
    padding-bottom: 100px;
}

.index-img {
    width: 100%;
    height: 210px;
    margin-top: 100px;
}

/*object-fit: cover;解决图片指定大小被压缩问题*/
.index-img>img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}