间距

Bootstrap 包括各种速记响应式边距、填充和间隙工具类，用于修改元素的外观。

外边距和填充

¥Margin and padding

使用速记类将响应友好的 margin 或 padding 值分配给元素或其边的子集。包括对单个属性、所有属性以及垂直和水平属性的支持。类是根据范围从 .25rem 到 3rem 的默认 Sass 映射构建的。

¥Assign responsive-friendly margin or padding values to an element or a subset of its sides with shorthand classes. Includes support for individual properties, all properties, and vertical and horizontal properties. Classes are built from a default Sass map ranging from .25rem to 3rem.

Using the CSS Grid layout module? Consider using the gap utility instead.

符号

¥Notation

适用于所有断点（从 xs 到 xxl）的间距工具中没有断点缩写。这是因为这些类是从 min-width: 0 及以上应用的，因此不受媒体查询的约束。然而，其余断点确实包含断点缩写。

¥Spacing utilities that apply to all breakpoints, from xs to xxl, have no breakpoint abbreviation in them. This is because those classes are applied from min-width: 0 and up, and thus are not bound by a media query. The remaining breakpoints, however, do include a breakpoint abbreviation.

这些类的命名格式为 {property}{sides}-{size} 代表 xs，{property}{sides}-{breakpoint}-{size} 代表 sm、md、lg、xl 和 xxl。

¥The classes are named using the format {property}{sides}-{size} for xs and {property}{sides}-{breakpoint}-{size} for sm, md, lg, xl, and xxl.

其中属性是以下之一：

¥Where property is one of:

m - 对于设置 margin 的类

¥m - for classes that set margin
p - 对于设置 padding 的类

¥p - for classes that set padding

其中 side 是以下之一：

¥Where sides is one of:

t - 对于设置 margin-top 或 padding-top 的类

¥t - for classes that set margin-top or padding-top
b - 对于设置 margin-bottom 或 padding-bottom 的类

¥b - for classes that set margin-bottom or padding-bottom
s - （开始）对于在 LTR 中设置 margin-left 或 padding-left、在 RTL 中设置 margin-right 或 padding-right 的类

¥s - (start) for classes that set margin-left or padding-left in LTR, margin-right or padding-right in RTL
e - （结束）对于在 LTR 中设置 margin-right 或 padding-right、在 RTL 中设置 margin-left 或 padding-left 的类

¥e - (end) for classes that set margin-right or padding-right in LTR, margin-left or padding-left in RTL
x - 对于同时设置 *-left 和 *-right 的类

¥x - for classes that set both *-left and *-right
y - 对于同时设置 *-top 和 *-bottom 的类

¥y - for classes that set both *-top and *-bottom
blank - 对于在元素的所有 4 侧设置 margin 或 padding 的类

¥blank - for classes that set a margin or padding on all 4 sides of the element

其中大小是以下之一：

¥Where size is one of:

0 - 对于通过将 margin 或 padding 设置为 0 来消除 margin 或 padding 的类

¥0 - for classes that eliminate the margin or padding by setting it to 0
1 - （默认情况下）对于将 margin 或 padding 设置为 $spacer * .25 的类

¥1 - (by default) for classes that set the margin or padding to $spacer * .25
2 - （默认情况下）对于将 margin 或 padding 设置为 $spacer * .5 的类

¥2 - (by default) for classes that set the margin or padding to $spacer * .5
3 - （默认情况下）对于将 margin 或 padding 设置为 $spacer 的类

¥3 - (by default) for classes that set the margin or padding to $spacer
4 - （默认情况下）对于将 margin 或 padding 设置为 $spacer * 1.5 的类

¥4 - (by default) for classes that set the margin or padding to $spacer * 1.5
5 - （默认情况下）对于将 margin 或 padding 设置为 $spacer * 3 的类

¥5 - (by default) for classes that set the margin or padding to $spacer * 3
auto - 对于将 margin 设置为自动的类

¥auto - for classes that set the margin to auto

（你可以通过向 $spacers Sass 映射变量添加条目来添加更多大小。）

¥(You can add more sizes by adding entries to the $spacers Sass map variable.)

示例

¥Examples

以下是这些类的一些代表性示例：

¥Here are some representative examples of these classes:

.mt-0 {
  margin-top: 0 !important;
}

.ms-1 {
  margin-left: ($spacer * .25) !important;
}

.px-2 {
  padding-left: ($spacer * .5) !important;
  padding-right: ($spacer * .5) !important;
}

.p-3 {
  padding: $spacer !important;
}

水平居中

¥Horizontal centering

此外，Bootstrap 还包括一个 .mx-auto 类，用于通过将水平边距设置为 auto 来水平居中固定宽度块级内容（即设置了 display: block 和 width 的内容）。

¥Additionally, Bootstrap also includes an .mx-auto class for horizontally centering fixed-width block level content—that is, content that has display: block and a width set—by setting the horizontal margins to auto.

Centered element

<div class="mx-auto p-2" style="width: 200px;">
  Centered element
</div>

负裕度

¥Negative margin

在 CSS 中，margin 属性可以使用负值（padding 不能）。默认情况下，这些负边距是禁用的，但可以通过设置 $enable-negative-margins: true 在 Sass 中启用。

¥In CSS, margin properties can utilize negative values (padding cannot). These negative margins are disabled by default, but can be enabled in Sass by setting $enable-negative-margins: true.

该语法与默认的正边距工具几乎相同，但在请求的大小之前添加了 n。下面是一个与 .mt-1 相反的示例类：

¥The syntax is nearly the same as the default, positive margin utilities, but with the addition of n before the requested size. Here’s an example class that’s the opposite of .mt-1:

.mt-n1 {
  margin-top: -0.25rem !important;
}

差距

¥Gap

使用 display: grid 或 display: flex 时，你可以在父元素上使用 gap 工具。这可以节省向网格或弹性容器的各个子项添加边距工具的麻烦。默认情况下，间隙工具是响应式的，并通过我们的工具 API 基于 $spacers Sass 映射生成。

¥When using display: grid or display: flex, you can make use of gap utilities on the parent element. This can save on having to add margin utilities to individual children of a grid or flex container. Gap utilities are responsive by default, and are generated via our utilities API, based on the $spacers Sass map.

Grid item 1

Grid item 2

Grid item 3

Grid item 4

html

<div style="grid-template-columns: 1fr 1fr;" class="d-grid gap-3">
  <div class="p-2">Grid item 1</div>
  <div class="p-2">Grid item 2</div>
  <div class="p-2">Grid item 3</div>
  <div class="p-2">Grid item 4</div>
</div>

支持包括所有 Bootstrap 网格断点的响应选项，以及 $spacers 映射 (0–5) 中的六种尺寸。没有 .gap-auto 工具类，因为它实际上与 .gap-0 相同。

¥Support includes responsive options for all of Bootstrap’s grid breakpoints, as well as six sizes from the $spacers map (0–5). There is no .gap-auto utility class as it’s effectively the same as .gap-0.

row-gap

row-gap 设置指定容器中子项之间的垂直间距。

¥row-gap sets the vertical space between children items in the specified container.

Grid item 1

Grid item 2

Grid item 3

Grid item 4

html

<div style="grid-template-columns: 1fr 1fr;" class="d-grid gap-0 row-gap-3">
  <div class="p-2">Grid item 1</div>
  <div class="p-2">Grid item 2</div>
  <div class="p-2">Grid item 3</div>
  <div class="p-2">Grid item 4</div>
</div>

column-gap

column-gap 设置指定容器中子项之间的水平间距。

¥column-gap sets the horizontal space between children items in the specified container.

Grid item 1

Grid item 2

Grid item 3

Grid item 4

html

<div style="grid-template-columns: 1fr 1fr;" class="d-grid gap-0 column-gap-3">
  <div class="p-2">Grid item 1</div>
  <div class="p-2">Grid item 2</div>
  <div class="p-2">Grid item 3</div>
  <div class="p-2">Grid item 4</div>
</div>

CSS

Sass 映射

¥Sass maps

间距工具通过 Sass 映射声明，然后使用我们的工具 API 生成。

¥Spacing utilities are declared via Sass map and then generated with our utilities API.

scss/_variables.scss

$spacer: 1rem;
$spacers: (
  0: 0,
  1: $spacer * .25,
  2: $spacer * .5,
  3: $spacer,
  4: $spacer * 1.5,
  5: $spacer * 3,
);

Sass 工具 API

¥Sass utilities API

间距工具在 scss/_utilities.scss 中的工具 API 中声明。Learn how to use the utilities API.

¥Spacing utilities are declared in our utilities API in scss/_utilities.scss. Learn how to use the utilities API.

scss/_utilities.scss

"margin": (
  responsive: true,
  property: margin,
  class: m,
  values: map-merge($spacers, (auto: auto))
),
"margin-x": (
  responsive: true,
  property: margin-right margin-left,
  class: mx,
  values: map-merge($spacers, (auto: auto))
),
"margin-y": (
  responsive: true,
  property: margin-top margin-bottom,
  class: my,
  values: map-merge($spacers, (auto: auto))
),
"margin-top": (
  responsive: true,
  property: margin-top,
  class: mt,
  values: map-merge($spacers, (auto: auto))
),
"margin-end": (
  responsive: true,
  property: margin-right,
  class: me,
  values: map-merge($spacers, (auto: auto))
),
"margin-bottom": (
  responsive: true,
  property: margin-bottom,
  class: mb,
  values: map-merge($spacers, (auto: auto))
),
"margin-start": (
  responsive: true,
  property: margin-left,
  class: ms,
  values: map-merge($spacers, (auto: auto))
),
// Negative margin utilities
"negative-margin": (
  responsive: true,
  property: margin,
  class: m,
  values: $negative-spacers
),
"negative-margin-x": (
  responsive: true,
  property: margin-right margin-left,
  class: mx,
  values: $negative-spacers
),
"negative-margin-y": (
  responsive: true,
  property: margin-top margin-bottom,
  class: my,
  values: $negative-spacers
),
"negative-margin-top": (
  responsive: true,
  property: margin-top,
  class: mt,
  values: $negative-spacers
),
"negative-margin-end": (
  responsive: true,
  property: margin-right,
  class: me,
  values: $negative-spacers
),
"negative-margin-bottom": (
  responsive: true,
  property: margin-bottom,
  class: mb,
  values: $negative-spacers
),
"negative-margin-start": (
  responsive: true,
  property: margin-left,
  class: ms,
  values: $negative-spacers
),
// Padding utilities
"padding": (
  responsive: true,
  property: padding,
  class: p,
  values: $spacers
),
"padding-x": (
  responsive: true,
  property: padding-right padding-left,
  class: px,
  values: $spacers
),
"padding-y": (
  responsive: true,
  property: padding-top padding-bottom,
  class: py,
  values: $spacers
),
"padding-top": (
  responsive: true,
  property: padding-top,
  class: pt,
  values: $spacers
),
"padding-end": (
  responsive: true,
  property: padding-right,
  class: pe,
  values: $spacers
),
"padding-bottom": (
  responsive: true,
  property: padding-bottom,
  class: pb,
  values: $spacers
),
"padding-start": (
  responsive: true,
  property: padding-left,
  class: ps,
  values: $spacers
),
// Gap utility
"gap": (
  responsive: true,
  property: gap,
  class: gap,
  values: $spacers
),
"row-gap": (
  responsive: true,
  property: row-gap,
  class: row-gap,
  values: $spacers
),
"column-gap": (
  responsive: true,
  property: column-gap,
  class: column-gap,
  values: $spacers
),