使用边框实用程序添加或删除元素的边框。从所有边框中选择，或者一次选择一个。

增加的

<span class="border"></span>
<span class="border-top"></span>
<span class="border-right"></span>
<span class="border-bottom"></span>
<span class="border-left"></span>

删减的

<span class="border-0"></span>
<span class="border-top-0"></span>
<span class="border-right-0"></span>
<span class="border-bottom-0"></span>
<span class="border-left-0"></span>

边框颜色

使用基于主题颜色构建的实用程序更改边框颜色。

<span class="border border-primary"></span>
<span class="border border-secondary"></span>
<span class="border border-success"></span>
<span class="border border-danger"></span>
<span class="border border-warning"></span>
<span class="border border-info"></span>
<span class="border border-light"></span>
<span class="border border-dark"></span>
<span class="border border-white"></span>

圆角边框

<img src="..." alt="..." class="rounded">
<img src="..." alt="..." class="rounded-top">
<img src="..." alt="..." class="rounded-right">
<img src="..." alt="..." class="rounded-bottom">
<img src="..." alt="..." class="rounded-left">
<img src="..." alt="..." class="rounded-circle">
<img src="..." alt="..." class="rounded-pill">
<img src="..." alt="..." class="rounded-0">

尺寸

使用 .rounded-lg 或 .rounded-lg 表示较大或较小的边界半径。

<img src="..." alt="..." class="rounded-sm">
<img src="..." alt="..." class="rounded-lg">