border border-top-0
bootstrap5.css
bootstrap5.css
.border-top-0 {
border-top: 0 !important;
}
html bootstrap5 Sample
ボーダーを削除する:border-0
<!-- 全ボーダー削除 -->
<span class="border border-0">border-0</span>
<span class="border border-top-0">border-top-0</span>
<span class="border border-right-0">border-right-0</span>
<span class="border border-bottom-0">border-bottom-0</span>
<span class="border border-left-0">border-left-0</span>