border-bottom

Sets the bottom border. Most used directional border for list separators, active tab indicators, section dividers.

Class List

ClassCSSDescription
bb0border-bottom: 0Remove bottom border
bb1pxsolidDDDDDDborder-bottom: 1px solid #DDDDDD1px light gray solid
bb1pxsolid27272Aborder-bottom: 1px solid #27272A1px dark solid (separator)
bb2pxsolid27272Aborder-bottom: 2px solid #27272A2px dark solid (header separator)
bb2pxsolid6366F1border-bottom: 2px solid #6366F12px indigo solid (active tab)
bb1pxdashed999999border-bottom: 1px dashed #9999991px gray dashed
bb3pxsolidFF0000border-bottom: 3px solid #FF00003px red solid (error)

Pattern

bb{크기}{단위}{스타일}{HEX6}

Combine width, unit, style, color (6-digit HEX) in order.

<tr> <th class="tal py12px px16px bg18181B bb2pxsolid27272A cA1A1AA fw600 ttu fs12px ls0-05em">PartDescriptionExample
bbborder-bottom prefixbb
{크기}Border width number1, 2, 3
{단위}Unit (px, etc.)px
{스타일}solid, dashed, dotted, doublesolid
{HEX6}6-digit HEX color code27272A

Visual Comparison

Visually compares border-bottom classes.

bb0 (remove) — bb0

Content area

1px solid dark — bb1pxsolid27272A

Content area

2px solid dark — bb2pxsolid27272A

Content area

2px solid indigo — bb2pxsolid6366F1

Content area

1px dashed — bb1pxdashed999999

Content area

Practical Patterns

border-bottom is most commonly used as a list item separator.

List item separator

List item 1

List item 2

List item 3 (last, no border)

Active tab indicator

Table header separator (bb2pxsolid27272A)

<tr> <th class="tal py12px px16px bb2pxsolid27272A cA1A1AA fw600">NameRole
홍길동개발자
김영희디자이너

Usage Examples

<!-- List item divider -->
<div class="bb1pxsolid27272A py16px">Item 1</div>
<div class="bb1pxsolid27272A py16px">Item 2</div>
<div class="py16px">Item 3 (Last)</div>

<!-- Tab active indicator -->
<div class="df bb1pxsolid27272A">
  <button class="py12px px2rem bb2pxsolid6366F1 cFAFAFA bn bg0F0F17 cp">Active</button>
  <button class="py12px px2rem bb0 c71717A bn bg0F0F17 cp">Inactive</button>
</div>

<!-- Remove bottom border -->
<td class="bb0">Cell without border</td>

<!-- Section bottom divider -->
<section class="bb1pxsolid27272A pb2rem mb2rem">
  <h2>Section Title</h2>
  <p>Separated from next section by bottom border</p>
</section>

Responsive

Combine with media query prefixes to change bottom border by screen size.

<!-- Bottom divider only on desktop -->
<div class="bb1pxsolid27272A sm-bb0 pb16px">
  Bottom border on desktop only
</div>

<!-- Add divider on mobile -->
<div class="bb0 sm-bb1pxsolid27272A pb16px">
  Bottom border only below 768px
</div>

Tips & Notes

Separator pattern: bb1pxsolid27272A

Most used separator in dark themes. Use bb1pxsolid27272A for list items, table rows, section dividers.

Handling last item

If last item's bottom border is unnecessary, apply bb0 or omit the class.

Use bb2pxsolid for table headers

Use bb2pxsolid27272A with 2px for clear header-body separation.