前端-第2周第2次-CSS(4)-2022·1·15.css

/* 背景相关设置 */
body {
    width: 100vw;
    height: 100vh;

    background-color: black;

    background-image: url('https://www.xidian.edu.cn/1a2020sydt/2022112.jpg');
    background-repeat: no-repeat;
    background-position: top center;
    background-size: cover;
    background-origin: border-box;
    background-attachment: fixed;

    min-width: 1200px;
}

/* nav设置 */
nav {
    width: 100vw;
    height: 100px;

    display: flex;
    justify-content: center;
    align-items: center;
}

/* logo部分 */
.logo {
    flex: 1;
}

/* 导航栏具体部分 */
.bar {
    flex: 4;

    display: flex;
    justify-content: center;
    align-items: center;

    padding: 0px 20px;

    position: relative;
}
.bar > li {
    flex: 1;
}
.bar > li > a {
    text-decoration: none;
    color: white;
    font-size: 20px;

    background-color: rgba(0, 0, 0, 0);

    display: flex;
    justify-content: center;
    align-items: center;

    width: auto;
    height: 2em;
}

/* 导航栏下拉框部分 */
.select {
    position: absolute;

    display: flex;
    justify-content: center;
    align-items: center;

    background-color: rgba(255, 255, 255, 75%);

    height: 200px;
    width: 1040px;
    padding: 20px 10px;
}
.left, .right {
    flex: 1;
}
.left > ul {
    display: flex;
    justify-content: left;
    align-items: center;
    flex-wrap: wrap;

    width: 66.7%;
    height: 100%;
}
.left > ul > li {
    display: flex;
    justify-content: left;
    align-items: center;

    width: 50%;
    height: 25%;
}
.left > ul > li > a {
    text-decoration: none;
    color: #666;

    line-height: 3em;
    text-align: left;

    display: block;
}

/* 鼠标移动响应 */
.select {
    display: none;
}
.bar > li:hover .select {
    display: flex;
}
.bar > li:hover {
    background-color: rgb(186, 0, 0);
}
.left > ul > li > a:hover {
    color: rgb(186, 0, 0);
}

/* 其他资源部分 */
.right-arrow {
    display: inline-block;
    position: relative;
    width: 9px;
    height: 9px;
    margin-right: 5px;
}
.right-arrow::after {
    display: inline-block;
    content: " ";
    height: 4.5px;
    width: 4.5px;
    border-width: 2px 2px 0 0;
    border-color: #666;
    border-style: solid;
    transform: matrix(0.71, 0.71, -0.71, 0.71, 0, 0);
    position: absolute;
    top: 50%;
    right: 3px;
    margin-top: -4.5px;
}
.clearfix::before, .clearfix::after{
    content: '';
    display: table;
    clear: both;
    /* 以下代码为了解决 IE 浏览器的兼容问题 */
    height: 0;
    overflow: hidden;
    /* 以下代码为了去隐藏content中的内容 */
    visibility: hidden;
}