实现CSS :nth-last-child(-n+4)伪类选择器的多种应用场景

<style>
.nav-bar div:nth-last-child(-n+4) {
    border-bottom: none;
}
</style>

<div class="nav-bar">
    <div>首页</div>
    <div>新闻</div>
    <div>产品</div>
    <div>关于</div>
    <div>联系</div>
    <div>更多</div>
</div>

<style>
.list-item:nth-last-child(-n+4) {
    color: red;
    font-weight: bold;
}
</style>

<ul>
    <li class="list-item">第1条内容</li>
    <li class="list-item">第2条内容</li>
    <li class="list-item">第3条内容</li>
    <li class="list-item">第4条内容</li>
    <li class="list-item">第5条内容</li>
    <li class="list-item">第6条内容</li>
</ul>

<style>
table td:nth-last-child(-n+4) {
    background-color: yellow;
    font-weight: bold;
}
</style>

<table>
    <tr>
        <td>1</td>
        <td>2</td>
        <td>3</td>
        <td>4</td>
        <td>5</td>
        <td>6</td>
        <td>7</td>
        <td>8</td>
    </tr>
    <tr>
        <td>1</td>
        <td>2</td>
        <td>3</td>
        <td>4</td>
        <td>5</td>
        <td>6</td>
        <td>7</td>
        <td>8</td>
    </tr>
</table>