*{
    margin: 0 auto;
    padding: 0;
}
body{
    background-image: url(pc.jpeg);
    background-repeat: repeat-y;
    -webkit-background-size: cover;
    background-size: cover;
}
h2{
    text-align: center;
    font-family: Lolita;
    font-size: 4rem;
}
h5{
    text-align: center;
    font-family: Lolita;
    font-size: 2rem;
}
.container{
}
.toplist{
    text-align: center;
    list-style-type: none;
}
.toplist>li{
    display: inline-block;
    font-size: 2.5rem;
    padding: 0 2%;
    border-left: 1px solid #333333;
    position: relative;
}
.toplist li:first-child{
     border-left: none;
 }
.toplist li .catalog{
    display: none;
    position: absolute; /* 父元素相对定位，子元素相对于父元素定位 */
    top: 3.4rem;
    background-color: rgba(255,255,255,0.75);
    border-radius: 5px;
    padding: 5px 0;
    box-shadow:0 3px 12px rgba(27,31,35,.15),0 0 1px rgba(27,31,35,.2);
}

.toplist>li .catalog>li{
    list-style-type: none;
    text-align: left;
    font-size: 1.3rem;
    font-weight: bold;
    padding:0.2rem;
}
.toplist>li .catalog>li>a{
    padding: 0.2rem 0; /*跟前面的padding 0.2rem对应，至于为什么我也不知道*/
    text-decoration: none;
    color: black;
}
.toplist>li .catalog>li:hover{
    background-color: rgba(0,0,0,0.75);
}
.toplist>li .catalog>li:hover a{
    color: #eee;
}
.center{
    display:flex;
    text-align: center;
    justify-self: center;
    align-items: center;
}
#mention{
    margin-top: 5%;
    padding: 5%;
    border: 4px solid #795da3;
    -webkit-border-radius: 20%;
    -moz-border-radius: 20%;
    border-radius: 20%;
    font-size: 1.7rem;
    font-family: 黑体;
    line-height: 1.5em;
}
#notice{
    font-size: 3rem;
    font-family: '萝莉体 第二版';
    line-height: 2em;
}

@media screen and (max-width:800px){
    body{
        background-image: url(mobile.jpg);
        background-repeat: repeat-y;
        -webkit-background-size: cover;
        background-size: cover;
    }
    .toplist li:nth-child(3){
        border-left: none;
    }
}
