这段代码怎么简化？

程序代码：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>淘宝广告栏</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        a {
            text-decoration: none;
        }
        ul {
            list-style: none;
        }
        .dahe {
            width: 540px;
            height: 300px;
            border: 1px solid red;
            margin: 50px auto;
        }
        .ad {
            width: 520px;
            height: 280px;
            background-color: #fff;
            margin: 10px;
            position: relative; /*给第二个盒子相对定位子绝父相*/
        }
        .tu-l,
        .tu-r {
            background-color: rgba(0,0,0,.4);
            width: 20px;
            height: 30px;
            text-align: center;
            line-height: 30px;
            position: absolute; /*给子盒子绝对定位*/
            top: 50%;            /*垂直居中两个按钮*/
            margin-top: -15px;

        }
        .tu-l a,
        .tu-r a {
            color: #fff;
            font-weight: 700;
        }
        .tu-l {
            left: 0;
            border-radius: 0 50% 50% 0;     /*左边圆角设置*/
        }

        .tu-r {
            right: 0;
            border-radius: 50% 0 0 50%;     /*右边圆角设置*/
        }
        .tu-h {
            width: 60px;
            height: 12px;
            background-color: rgba(255,255,255,0.4);
            border-radius: 10px;
            position: absolute;
            left: 50%;                    /*垂直居中下方按钮*/
            margin-left: -30px;
            bottom: 30px;
        }
        .tu-h li {
            width: 8px;
            height: 8px;
            background-color: #fff;
            float: left;
            margin: 2px;
            border-radius: 50%; /*给li盒子改变圆形*/
        }
        .tu-h li:hover {
            background-color: #f40;
        }
    </style>
</head>
<body>
<div class="dahe">
    <div class="ad">
        <img src="imges/tu.jpg" alt="图像被外星人带走了" />
        <div class="tu-l"><a href="#">></a></div>
        <div class="tu-r"><a href="#"><</a></div>
        <div class="tu-h">
            <ul>
                <li><a href="#"></a></li>
                <li><a href="#"></a></li>
                <li><a href="#"></a></li>
                <li><a href="#"></a></li>
                <li><a href="#"></a></li>
            </ul>
        </div>
    </div>
</div>
</body>
</html>