【项目2-3】手机邮箱导航页面

效果：

前导知识

a:link 初始状态

a:hover 悬停状态

a:active 单击时的状态

a:visited 访问后的状态

love hate 顺序。

项目实战

分析：

步骤

①HTML 布局

②设置基线同父元素对齐，调整元素位置

③使用font-awesome图标

④设置 a 标签

⑤右侧带样式的文字用 CSS+ <span> 标签控制

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <link href="../0203/css/font-awesome.min.css" rel="stylesheet">
    <link rel='stylesheet' href='css/email.css'>
</head>
<body>
    <div class="l-main">
        <div class="menu">
            <header class="menu_header">
                <h1 class="menu_header-title">我的邮箱</h1>
            </header>
            <nav class="menu_body">
                <ul class="nav">
                    <li class="nav_item"><a href=“#" class="nav_item-link is-active">
                    <i class="fa fa-envelope nav_item-icon"></i>
                    <span class="nav_item-text">收件箱</span>
                    <span class="badge badge-warning">32</span> </a></li>
                <li class="nav_item"><a href="#" class="nav_item-link"><i class="fa fa-flag nav_item-icon">
                </i><span class="nav_item-text">红旗邮件</span> <span class="badge">7</span></a>
                </li>
                <li class="nav_item"><a href="#" class="nav_item-link"><i class="fa fa-space-shuttle nav_item-icon">
                </i><span class="nav_item-text">已发送</span> <span class="badge">0/17</span></a>
                </li>
                <li class="nav_item"><a href="#" class="nav_item-link"><i class="fa fa-archive nav_item-icon">
                </i><span class="nav_item-text">草稿箱</span> <span class="badge">2</span></a>
                </li>
                <li class="nav_item"><a href="#" class="nav_item-link"><i class="fa fa-trash nav_item-icon">
                </i><span class="nav_item-text">已删除</span> <span class="badge">5</span></a>
                </li>
                <li class="nav_item"><a href="#" class="nav_item-link"><span class="nav_item-text">
                        所有邮件</span> </a></li>
                </ul>
            </nav>
        </div>
    </div>
</body>
</html>

CSS

html,body,div,span,h1,a,ul,li,nav{
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 100%;
  font: inherit;  /*字体设置，所有元素保持一致*/
  vertical-align: baseline; /*元素的基线与父元素的基线对齐*/
}

body{
  line-height: 1em;
  background-color: #f4f4f4;
  font-family: Arial,sans-serif;
  font-size: 14px;
  font-weight: lighter;    /*lighter 轻轻地*/
}
.l-main{
  width: 530px;
  margin: 0 auto;
}
.menu{
  width: 250px;
  margin: 40px;
  background: #fff;
  box-shadow: 0 1px 4px rgba(0,0,0,.3);
  border-radius: 5px;
  float: left;
}
.menu_header{
  background-color: #4b4f55;
  border-bottom: 1px solid #353a40;
  border-radius: 5px 5px 0 0 ;
}
.menu_header-title{
  color: #fff;
  padding: 15px;
  text-shadow: 0 1px 0 rgba(0,0,0,0.4);
}
.menu_body{
  border-radius: 0 0 5px 5px;
}
.nav{
  list-style: none;
}
.nav_item{
  position: relative;
}
.nav_item-link{
  padding: 10px 15px;
  text-decoration: none;
  color: #8b8e93;
  display: block;
  border-bottom: 1px solid #f0f0f0;
}
.nav_item-link:hover{
  background: #f0f0f0;
}
.nav_item-link.is-active{
  background: #6e757f;
  color: #fff;
  border-bottom-color: #4b4f55;
  box-shadow: 0 1px 0 #7a828d inset;   /*inset 内嵌效果*/
}
.nav_item-link.is-active:after{
  content: "";
  display: block;
  position: absolute;
  top: 50%;
  right: -6px;
  margin-top: -6px;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
  border-left: 6px solid #6e757f;
}
.nav_item-link.is-active{
  color: #fff;
}
.nav_item:last-child .nav_item-link{
  border-bottom: none;
}
.nav_item-icon{
  width: 20px;
  text-align: center;
  font-size: 18px;
  margin-right: 10px;
}
.badge{
  font-size: 12px;
  padding: 2px 8px;
  border: 1px solid #d1d1d1;
  border-radius: 10px;
  position: absolute;
  top: 10px;
  right: 15px;
}
.badge-warning{
  background: #ed373f;
  border-color: #ed373f;
}
.fa-flag{
  color: red;
}
.fa-archive{
  color: orange;
}
.fa-envelope{
  color: #35b3ff;
}

总结

利用 :after 来画三角

ul 下的第一个 li 标签下的 a 元素添加 class=“nav_item-link is-active”

先设置父元素 li 相对定位，再设置 a 元素绝对定位