* {
    padding: 0;
    margin: 0;
}

h1,
h2,
h3,
h4,
h5,
h6,
li {
    text-align: center;
}

body {
    display: grid;
    grid-template-rows: auto 1fr auto;
    /* wealcome-section
        main 
       footer */
    background-size: 100vw 100vh;
    font-family: Menlo, Monaco, 'Courier New', monospace;
    /* background-image: url(/img/background-by-lowpoly.png); */
    background-color: #dad1e9;
    /* background-color: #bbff0f; */
}

a:link {
    text-decoration: none;
}

a:visited {
    text-decoration: none;
}

a:hover {
    text-decoration: none;
    color: #000000;
}

a:active {
    text-decoration: none;
}

/* 以上为初始化 */

/* 菜单栏 */
.topnav{
    z-index: 3;
    position: fixed;
    top: 0;
    left: 0;
}

.topnav-ul {
    list-style-type: none;
    height: 40px;
    width: 100vw;
    background-color: #A294F9;
}

.topnav-ul>li {
    width: 40px;
    height: 20px;
    padding: 10px 30px;
    float: right;
    display: block;
    transition: background-color 0.1s ease-in;
}

.topnav-ul>li:hover {
    background-color: #664fff;
}


/* 固定模版主题内容 */

/* 欢迎页面 */

.wealcome-section {
    grid-row: 1;
}

.wealcome-section>h1 {
    /* 大标题 */
    top: 45vh;
    width: 100vw;
    position: absolute;
}
#cas {
    /* 背景动画画布 */
    /* 使用动画js.js */
    position: absolute;
    top: 0;
    left: 0;
    z-index: -1;
}

/* 主体 */

.main {
    grid-row: 2;
}

.tip {
    /* border-radius: 8px; */
    transition: all 0.3s ease;
    /* position: relative; */
}


.tip:hover {
    background-color: #a294f9;
    transform: translateY(-4px);
    box-shadow: 0px 2px 8px 0;
}

/* 脚注 */

.footer {
    grid-row: 3;
    height: 200px;
    margin-top: 40px;
    background-color: #6c63d2;
}