一款纯css实现的漂亮导航

  <div class="l-main">
        <div class="menu">
            <header class="menu__header">
                <h1 class="menu__header-title">
                    Incoming Messages</h1>
            </header>
            <div class="menu__body">
                <ul class="nav">
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link is-active">
                        <i class="fa fa-envelope nav__item-icon"></i><span class="nav__item-text">News</span>
                        <span class="badge badge--warning">32</span> </a></li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-flag nav__item-icon">
                    </i><span class="nav__item-text">Priority</span> <span class="badge">8</span> </a>
                    </li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-space-shuttle nav__item-icon">
                    </i><span class="nav__item-text">Assigned</span> <span class="badge">0/17</span> </a>
                    </li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-archive nav__item-icon">
                    </i><span class="nav__item-text">Archived</span> <span class="badge">3</span> </a>
                    </li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-trash nav__item-icon">
                    </i><span class="nav__item-text">Deleted</span> <span class="badge">9</span> </a>
                    </li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><span class="nav__item-text">
                        Show all</span> </a></li>
                </ul>
            </div>
        </div>
        <div class="menu menu--small">
            <header class="menu__header">
                <h1 class="menu__header-title">
                    Incoming</h1>
            </header>
            <div class="menu__body">
                <ul class="nav">
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link is-active"><i class="fa fa-envelope nav__item-icon">
                    </i><span class="badge badge--warning">32</span> </a></li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-flag nav__item-icon">
                    </i><span class="badge">8</span> </a></li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-space-shuttle nav__item-icon">
                    </i><span class="badge">0/17</span> </a></li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-archive nav__item-icon">
                    </i><span class="badge">3</span> </a></li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><i class="fa fa-trash nav__item-icon">
                    </i><span class="badge">9</span> </a></li>
                    <li class="nav__item"><a href="http://www.w2bc.com" class="nav__item-link"><span class="nav__item-text">
                        Show all</span> </a></li>
                </ul>
            </div>
        </div>
    </div>

    body
        {
            background: #F4F4F4;
            font-family: Arial, sans-serif;
            font-size: 14px;
            font-weight: lighter;
        }
        
        .l-main
        {
            width: 530px;
            margin: 0 auto;
        }
        
        .menu
        {
            width: 250px;
            margin: 40px;
            background: #fff;
            box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
            border-radius: 5px;
            float: left;
        }
        
        .menu__header
        {
            background: #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;
        }
        
        .menu--small
        {
            width: 110px;
        }
        
        .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;
        }
        .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 .nav__item-icon
        {
            color: #fff;
        }
        .nav__item:last-child .nav__item-link
        {
            border-bottom: none;
        }
        
        .nav__item-icon
        {
            color: #D2D5DA;
            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;
        }