* {
    margin: 0;
    padding: 0;
}
html,body {
    width: 100%;
    height: 100%;
}
a {
    text-decoration: none; /* 去掉下划线 */
    color: inherit; /* 继承父元素颜色 */
}
.bg {
    width: 100%;
    height: 100%;
    background-image: url(img/background.jpg);
    background-size: cover;
    background-repeat: no-repeat;
}
ul,li {
    margin: 0;
    padding: 0;
    list-style: none;
}
.top {
    text-align: right;
    height: 50px;
}
.top > div {
    display: inline-block;
}
.top img {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    overflow: hidden;
}
#user {
    position: relative;
    display: inline-block;
    height: 30px;
    text-decoration: none;
    line-height: 24px;
    font-size: 13px;
    margin: 15px 20px 0 0;
    display: inline-block;
    vertical-align: top;
    cursor: pointer;
    color: #ccc;
}
.top-img-wrapper {
    position: relative;
    width: 28px;
    height: 28px;
    border: 1px solid #4e71f2;
    display: inline-block;
    border-radius: 50%;
}
.top-img-wrapper img {
    padding: 2px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
}
.top-username {
    display: inline-block;
    max-width: 100px;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    -o-text-overflow: ellipsis;
    vertical-align: top;
    margin-top: 5px;
    margin-left: 8px;
    font: 13px/23px Arial,sans-serif;
}
/* .top-username:after {
    content: " ";
    display: inline-block;
    width: 6px;
    height: 6px;
    border-left: 1px solid transparent;
    border-bottom: 1px solid transparent;
    border-right: 1px solid #ccc;
    border-top: 1px solid #ccc;
    -ms-transform-origin: 50% 50%;
    transform-origin: 50% 50%;
    -ms-transform: rotate(135deg);
    transform: rotate(135deg);
    width: 5px;
    height: 5px;
    margin-left: 2px;
} */

.main {
    max-width: 1080px;
    padding-top: 10%;
    margin: auto;
}
.main li {
    display: inline-block;
    text-align: center;
    margin: 5px;
    font-size: 14px;
    color: #ccc;
    width: 200px;
    height: 200px;    
    vertical-align: top;
    margin-bottom: 10px;
}
.main li img {
    width: 180px;
    height: 180px;
    border: 1px solid #4e71f2;
    border-radius: 20%;
}
li a:hover img {
    width: 190px;
    height: 190px;
    position: relative;
    top: -5px;
}