<section>
            <h1 style="text-align: center;margin-top: 60px;margin-bottom: 40px;font-size: 24px">合作伙伴</h1>
            <div class="wrap">
                <!--第二层-->
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>4<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>5<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>6<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>7<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>5<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#" style="margin-right: 0px"><s></s>5<b></b></a>
                <!--第三层-->
                <a class="nav " target="_blank" href="http://www.mamicode.com/#" style="margin-left: 58px"><s></s>8<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>9<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>10<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>11<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>12<b></b></a>
                <!--第4层-->
                <a class="nav " target="_blank" href="http://www.mamicode.com/#" style="margin-left: 116px"><s></s>4<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>5<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>6<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>7<b></b></a>
                <!--第5层-->
                <a class="nav " target="_blank" href="http://www.mamicode.com/#" style="margin-left: 173px"><s></s>1<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>2<b></b></a>
                <a class="nav " target="_blank" href="http://www.mamicode.com/#"><s></s>3<b></b></a>
            </div>
        </section>

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    text-align: center;
    color: #ffffff;
    font-size: 14px;
    text-decoration: none;
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    margin-top: 50px;
    margin-right: 12px;
}

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    width: 0;
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    position: absolute;
    border-left: 50px dotted transparent;
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    border-bottom: 30px solid #28cb75;
    left: 0px;
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}

.nav b {
    width: 0;
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}