--- layout: default title: CSS slug: css lead: "Global CSS settings, fundamental HTML elements styled and enhanced with extensible classes, and an advanced grid system." ---

Overview

Get the lowdown on the key pieces of Bootstrap's infrastructure, including our approach to better, faster, stronger web development.

HTML5 doctype

Bootstrap makes use of certain HTML elements and CSS properties that require the use of the HTML5 doctype. Include it at the beginning of all your projects.

{% highlight html %} ... {% endhighlight %}

Mobile first

With Bootstrap 2, we added optional mobile friendly styles for key aspects of the framework. With Bootstrap 3, we've rewritten the project to be mobile friendly from the start. Instead of adding on optional mobile styles, they're baked right into the core. In fact, Bootstrap is mobile first. Mobile first styles can be found throughout the entire library instead of in separate files.

To ensure proper rendering and touch zooming, add the viewport meta tag to your <head>.

{% highlight html %} {% endhighlight %}

You can disable zooming capabilities on mobile devices by adding user-scalable=no to the viewport meta tag. This disables zooming, meaning users are only able to scroll, and results in your site feeling a bit more like a native application. Overall, we don't recommend this on every site, so use caution!

{% highlight html %} {% endhighlight %}

Bootstrap sets basic global display, typography, and link styles. Specifically, we:

These styles can be found within scaffolding.less.

Normalize.css

For improved cross-browser rendering, we use Normalize.css, a project by Nicolas Gallagher and Jonathan Neal.

Containers

Easily center a page's contents by wrapping its contents in a .container. Containers set width at various media query breakpoints to match our grid system.

Note that, due to padding and fixed widths, containers are not nestable by default.

{% highlight html %}
...
{% endhighlight %}

Grid system

Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases. It includes predefined classes for easy layout options, as well as powerful mixins for generating more semantic layouts.

Introduction

Grid systems are used for creating page layouts through a series of rows and columns that house your content. Here's how the Bootstrap grid system works:

Look to the examples for applying these principles to your code.

Media queries

We use the following media queries in our Less files to create the key breakpoints in our grid system.

{% highlight scss %} /* Extra small devices (phones, less than 768px) */ /* No media query since this is the default in Bootstrap */ /* Small devices (tablets, 768px and up) */ @media (min-width: @screen-sm-min) { ... } /* Medium devices (desktops, 992px and up) */ @media (min-width: @screen-md-min) { ... } /* Large devices (large desktops, 1200px and up) */ @media (min-width: @screen-lg-min) { ... } {% endhighlight %}

We occasionally expand on these media queries to include a max-width to limit CSS to a narrower set of devices.

{% highlight scss %} @media (max-width: @screen-xs-max) { ... } @media (min-width: @screen-sm-min) and (max-width: @screen-sm-max) { ... } @media (min-width: @screen-md-min) and (max-width: @screen-md-max) { ... } @media (min-width: @screen-lg-min) { ... } {% endhighlight %}

Grid options

See how aspects of the Bootstrap grid system work across multiple devices with a handy table.

Extra small devices Phones (<768px) Small devices Tablets (≥768px) Medium devices Desktops (≥992px) Large devices Desktops (≥1200px)
Grid behavior Horizontal at all times Collapsed to start, horizontal above breakpoints
Container width None (auto) 750px 970px 1170px
Class prefix .col-xs- .col-sm- .col-md- .col-lg-
# of columns 12
Column width Auto 60px 78px 95px
Gutter width 30px (15px on each side of a column)
Nestable Yes
Offsets Yes
Column ordering Yes

Grid classes apply to devices with screen widths greater than or equal to the breakpoint sizes, and override grid classes targeted at smaller devices. Therefore, applying any .col-md- class to an element will not only affect its styling on medium devices but also on large devices if a .col-lg- class is not present.

Example: Stacked-to-horizontal

Using a single set of .col-md-* grid classes, you can create a basic grid system that starts out stacked on mobile devices and tablet devices (the extra small to small range) before becoming horizontal on desktop (medium) devices. Place grid columns in any .row.

.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-8
.col-md-4
.col-md-4
.col-md-4
.col-md-4
.col-md-6
.col-md-6
{% highlight html %}
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-8
.col-md-4
.col-md-4
.col-md-4
.col-md-4
.col-md-6
.col-md-6
{% endhighlight %}

Example: Fluid container

Turn any fixed-width grid layout into a full-width layout by changing your outermost .container to .container-fluid.

{% highlight html %}
...
{% endhighlight %}

Example: Mobile and desktop

Don't want your columns to simply stack in smaller devices? Use the extra small and medium device grid classes by adding .col-xs-* .col-md-* to your columns. See the example below for a better idea of how it all works.

.col-xs-12 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6
.col-xs-6
{% highlight html %}
.col-xs-12 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6
.col-xs-6
{% endhighlight %}

Example: Mobile, tablet, desktops

Build on the previous example by creating even more dynamic and powerful layouts with tablet .col-sm-* classes.

.col-xs-12 .col-sm-6 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4
{% highlight html %}
.col-xs-12 .col-sm-6 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4
{% endhighlight %}

Responsive column resets

With the four tiers of grids available you're bound to run into issues where, at certain breakpoints, your columns don't clear quite right as one is taller than the other. To fix that, use a combination of a .clearfix and our responsive utility classes.

.col-xs-6 .col-sm-3
Resize your viewport or check it out on your phone for an example.
.col-xs-6 .col-sm-3
.col-xs-6 .col-sm-3
.col-xs-6 .col-sm-3
{% highlight html %}
.col-xs-6 .col-sm-3
.col-xs-6 .col-sm-3
.col-xs-6 .col-sm-3
.col-xs-6 .col-sm-3
{% endhighlight %}

In addition to column clearing at responsive breakpoints, you may need to reset offsets, pushes, or pulls. See this in action in the grid example.

{% highlight html %}
.col-sm-5 .col-md-6
.col-sm-5 .col-sm-offset-2 .col-md-6 .col-md-offset-0
.col-sm-6 .col-md-5 .col-lg-6
.col-sm-6 .col-md-5 .col-md-offset-2 .col-lg-6 .col-lg-offset-0
{% endhighlight %}

Offsetting columns

Move columns to the right using .col-md-offset-* classes. These classes increase the left margin of a column by * columns. For example, .col-md-offset-4 moves .col-md-4 over four columns.

.col-md-4
.col-md-4 .col-md-offset-4
.col-md-3 .col-md-offset-3
.col-md-3 .col-md-offset-3
.col-md-6 .col-md-offset-3
{% highlight html %}
.col-md-4
.col-md-4 .col-md-offset-4
.col-md-3 .col-md-offset-3
.col-md-3 .col-md-offset-3
.col-md-6 .col-md-offset-3
{% endhighlight %}

Nesting columns

To nest your content with the default grid, add a new .row and set of .col-md-* columns within an existing .col-md-* column. Nested rows should include a set of columns that add up to 12 or less.

Level 1: .col-md-9
Level 2: .col-md-6
Level 2: .col-md-6
{% highlight html %}
Level 1: .col-md-9
Level 2: .col-md-6
Level 2: .col-md-6
{% endhighlight %}

Column ordering

Easily change the order of our built-in grid columns with .col-md-push-* and .col-md-pull-* modifier classes.

.col-md-9 .col-md-push-3
.col-md-3 .col-md-pull-9
{% highlight html %}
.col-md-9 .col-md-push-3
.col-md-3 .col-md-pull-9
{% endhighlight %}

Less mixins and variables

In addition to prebuilt grid classes for fast layouts, Bootstrap includes Less variables and mixins for quickly generating your own simple, semantic layouts.

Variables

Variables determine the number of columns, the gutter width, and the media query point at which to begin floating columns. We use these to generate the predefined grid classes documented above, as well as for the custom mixins listed below.

{% highlight scss %} @grid-columns: 12; @grid-gutter-width: 30px; @grid-float-breakpoint: 768px; {% endhighlight %}

Mixins

Mixins are used in conjunction with the grid variables to generate semantic CSS for individual grid columns.

{% highlight scss %} // Creates a wrapper for a series of columns .make-row(@gutter: @grid-gutter-width) { // Then clear the floated columns .clearfix(); @media (min-width: @screen-sm-min) { margin-left: (@gutter / -2); margin-right: (@gutter / -2); } // Negative margin nested rows out to align the content of columns .row { margin-left: (@gutter / -2); margin-right: (@gutter / -2); } } // Generate the extra small columns .make-xs-column(@columns; @gutter: @grid-gutter-width) { position: relative; // Prevent columns from collapsing when empty min-height: 1px; // Inner gutter via padding padding-left: (@gutter / 2); padding-right: (@gutter / 2); // Calculate width based on number of columns available @media (min-width: @grid-float-breakpoint) { float: left; width: percentage((@columns / @grid-columns)); } } // Generate the small columns .make-sm-column(@columns; @gutter: @grid-gutter-width) { position: relative; // Prevent columns from collapsing when empty min-height: 1px; // Inner gutter via padding padding-left: (@gutter / 2); padding-right: (@gutter / 2); // Calculate width based on number of columns available @media (min-width: @screen-sm-min) { float: left; width: percentage((@columns / @grid-columns)); } } // Generate the small column offsets .make-sm-column-offset(@columns) { @media (min-width: @screen-sm-min) { margin-left: percentage((@columns / @grid-columns)); } } .make-sm-column-push(@columns) { @media (min-width: @screen-sm-min) { left: percentage((@columns / @grid-columns)); } } .make-sm-column-pull(@columns) { @media (min-width: @screen-sm-min) { right: percentage((@columns / @grid-columns)); } } // Generate the medium columns .make-md-column(@columns; @gutter: @grid-gutter-width) { position: relative; // Prevent columns from collapsing when empty min-height: 1px; // Inner gutter via padding padding-left: (@gutter / 2); padding-right: (@gutter / 2); // Calculate width based on number of columns available @media (min-width: @screen-md-min) { float: left; width: percentage((@columns / @grid-columns)); } } // Generate the medium column offsets .make-md-column-offset(@columns) { @media (min-width: @screen-md-min) { margin-left: percentage((@columns / @grid-columns)); } } .make-md-column-push(@columns) { @media (min-width: @screen-md-min) { left: percentage((@columns / @grid-columns)); } } .make-md-column-pull(@columns) { @media (min-width: @screen-md-min) { right: percentage((@columns / @grid-columns)); } } // Generate the large columns .make-lg-column(@columns; @gutter: @grid-gutter-width) { position: relative; // Prevent columns from collapsing when empty min-height: 1px; // Inner gutter via padding padding-left: (@gutter / 2); padding-right: (@gutter / 2); // Calculate width based on number of columns available @media (min-width: @screen-lg-min) { float: left; width: percentage((@columns / @grid-columns)); } } // Generate the large column offsets .make-lg-column-offset(@columns) { @media (min-width: @screen-lg-min) { margin-left: percentage((@columns / @grid-columns)); } } .make-lg-column-push(@columns) { @media (min-width: @screen-lg-min) { left: percentage((@columns / @grid-columns)); } } .make-lg-column-pull(@columns) { @media (min-width: @screen-lg-min) { right: percentage((@columns / @grid-columns)); } } {% endhighlight %}

Example usage

You can modify the variables to your own custom values, or just use the mixins with their default values. Here's an example of using the default settings to create a two-column layout with a gap between.

{% highlight scss %} .wrapper { .make-row(); } .content-main { .make-lg-column(8); } .content-secondary { .make-lg-column(3); .make-lg-column-offset(1); } {% endhighlight %} {% highlight html %}
...
...
{% endhighlight %}

Typography

Headings

All HTML headings, <h1> through <h6>, are available. .h1 through .h6 classes are also available, for when you want to match the font styling of a heading but still want your text to be displayed inline.

h1. Bootstrap heading

 Semibold 36px

h2. Bootstrap heading

 Semibold 30px

h3. Bootstrap heading

 Semibold 24px

h4. Bootstrap heading

 Semibold 18px
h5. Bootstrap heading
 Semibold 14px
h6. Bootstrap heading
 Semibold 12px
{% highlight html %}

h1. Bootstrap heading

h2. Bootstrap heading

h3. Bootstrap heading

h4. Bootstrap heading

h5. Bootstrap heading
h6. Bootstrap heading
{% endhighlight %}

Create lighter, secondary text in any heading with a generic <small> tag or the .small class.

h1. Bootstrap heading Secondary text

h2. Bootstrap heading Secondary text

h3. Bootstrap heading Secondary text

h4. Bootstrap heading Secondary text
h5. Bootstrap heading Secondary text
h6. Bootstrap heading Secondary text
{% highlight html %}

h1. Bootstrap heading Secondary text

h2. Bootstrap heading Secondary text

h3. Bootstrap heading Secondary text

h4. Bootstrap heading Secondary text

h5. Bootstrap heading Secondary text
h6. Bootstrap heading Secondary text
{% endhighlight %}

Body copy

Bootstrap's global default font-size is 14px, with a line-height of 1.428. This is applied to the <body> and all paragraphs. In addition, <p> (paragraphs) receive a bottom margin of half their computed line-height (10px by default).

Nullam quis risus eget urna mollis ornare vel eu leo. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nullam id dolor id nibh ultricies vehicula.

Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec ullamcorper nulla non metus auctor fringilla. Duis mollis, est non commodo luctus, nisi erat porttitor ligula, eget lacinia odio sem nec elit. Donec ullamcorper nulla non metus auctor fringilla.

Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Duis mollis, est non commodo luctus, nisi erat porttitor ligula, eget lacinia odio sem nec elit.

{% highlight html %}

...

{% endhighlight %}

Lead body copy

Make a paragraph stand out by adding .lead.

Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor. Duis mollis, est non commodo luctus.

{% highlight html %}

...

{% endhighlight %}

Built with Less

The typographic scale is based on two Less variables in variables.less: @font-size-base and @line-height-base. The first is the base font-size used throughout and the second is the base line-height. We use those variables and some simple math to create the margins, paddings, and line-heights of all our type and more. Customize them and Bootstrap adapts.

Emphasis

Make use of HTML's default emphasis tags with lightweight styles.

Small text

For de-emphasizing inline or blocks of text, use the <small> tag to set text at 85% the size of the parent. Heading elements receive their own font-size for nested <small> elements.

You may alternatively use an inline element with .small in place of any <small>.

This line of text is meant to be treated as fine print.

{% highlight html %} This line of text is meant to be treated as fine print. {% endhighlight %}

Bold

For emphasizing a snippet of text with a heavier font-weight.

The following snippet of text is rendered as bold text.

{% highlight html %} rendered as bold text {% endhighlight %}

Italics

For emphasizing a snippet of text with italics.

The following snippet of text is rendered as italicized text.

{% highlight html %} rendered as italicized text {% endhighlight %}

Alternate elements

Feel free to use <b> and <i> in HTML5. <b> is meant to highlight words or phrases without conveying additional importance while <i> is mostly for voice, technical terms, etc.

Alignment classes

Easily realign text to components with text alignment classes.

Left aligned text.

Center aligned text.

Right aligned text.

Justified text.

{% highlight html %}

Left aligned text.

Center aligned text.

Right aligned text.

Justified text.

{% endhighlight %}

Abbreviations

Stylized implementation of HTML's <abbr> element for abbreviations and acronyms to show the expanded version on hover. Abbreviations with a title attribute have a light dotted bottom border and a help cursor on hover, providing additional context on hover.

Basic abbreviation

For expanded text on long hover of an abbreviation, include the title attribute with the <abbr> element.

An abbreviation of the word attribute is attr.

{% highlight html %} attr {% endhighlight %}

Initialism

Add .initialism to an abbreviation for a slightly smaller font-size.

HTML is the best thing since sliced bread.

{% highlight html %} HTML {% endhighlight %}

Addresses

Present contact information for the nearest ancestor or the entire body of work. Preserve formatting by ending all lines with <br>.

Twitter, Inc.
795 Folsom Ave, Suite 600
San Francisco, CA 94107
P: (123) 456-7890
Full Name
first.last@example.com
{% highlight html %}
Twitter, Inc.
795 Folsom Ave, Suite 600
San Francisco, CA 94107
P: (123) 456-7890
Full Name
first.last@example.com
{% endhighlight %}

Blockquotes

For quoting blocks of content from another source within your document.

Default blockquote

Wrap <blockquote> around any HTML as the quote. For straight quotes, we recommend a <p>.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.

{% highlight html %}

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.

{% endhighlight %}

Blockquote options

Style and content changes for simple variations on a standard <blockquote>.

Naming a source

Add a <footer> for identifying the source. Wrap the name of the source work in <cite>.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.

Someone famous in Source Title
{% highlight html %}

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.

Someone famous in Source Title
{% endhighlight %}

Alternate displays

Add .blockquote-reverse for a blockquote with right-aligned content.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer posuere erat a ante.

Someone famous in Source Title
{% highlight html %}
...
{% endhighlight %}

Lists

Unordered

A list of items in which the order does not explicitly matter.

{% highlight html %} {% endhighlight %}

Ordered

A list of items in which the order does explicitly matter.

  1. Lorem ipsum dolor sit amet
  2. Consectetur adipiscing elit
  3. Integer molestie lorem at massa
  4. Facilisis in pretium nisl aliquet
  5. Nulla volutpat aliquam velit
  6. Faucibus porta lacus fringilla vel
  7. Aenean sit amet erat nunc
  8. Eget porttitor lorem
{% highlight html %}
  1. ...
{% endhighlight %}

Unstyled

Remove the default list-style and left margin on list items (immediate children only). This only applies to immediate children list items, meaning you will need to add the class for any nested lists as well.

{% highlight html %} {% endhighlight %}

Inline

Place all list items on a single line with display: inline-block; and some light padding.

{% highlight html %} {% endhighlight %}

Description

A list of terms with their associated descriptions.

Description lists
A description list is perfect for defining terms.
Euismod
Vestibulum id ligula porta felis euismod semper eget lacinia odio sem nec elit.
Donec id elit non mi porta gravida at eget metus.
Malesuada porta
Etiam porta sem malesuada magna mollis euismod.
{% highlight html %}
...
...
{% endhighlight %}

Horizontal description

Make terms and descriptions in <dl> line up side-by-side. Starts off stacked like default <dl>s, but when the navbar expands, so do these.

Description lists
A description list is perfect for defining terms.
Euismod
Vestibulum id ligula porta felis euismod semper eget lacinia odio sem nec elit.
Donec id elit non mi porta gravida at eget metus.
Malesuada porta
Etiam porta sem malesuada magna mollis euismod.
Felis euismod semper eget lacinia
Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.
{% highlight html %}
...
...
{% endhighlight %}

Auto-truncating

Horizontal description lists will truncate terms that are too long to fit in the left column with text-overflow. In narrower viewports, they will change to the default stacked layout.

Code

Inline

Wrap inline snippets of code with <code>.

For example, <section> should be wrapped as inline.
{% highlight html %} For example, <section> should be wrapped as inline. {% endhighlight %}

User input

Use the <kbd> to indicate input that is typically entered via keyboard.

To switch directories, type cd followed by the name of the directory.
{% highlight html %} To switch directories, type cd followed by the name of the directory. {% endhighlight %}

Basic block

Use <pre> for multiple lines of code. Be sure to escape any angle brackets in the code for proper rendering.

<p>Sample text here...</p>
{% highlight html %} 
<p>Sample text here...</p>
{% endhighlight %}

You may optionally add the .pre-scrollable class, which will set a max-height of 350px and provide a y-axis scrollbar.

Tables

Basic example

For basic styling—light padding and only horizontal dividers—add the base class .table to any <table>. It may seem super redundant, but given the widespread use of tables for other plugins like calendars and date pickers, we've opted to isolate our custom table styles.

# First Name Last Name Username
1 Mark Otto @mdo
2 Jacob Thornton @fat
3 Larry the Bird @twitter
{% highlight html %} ...
{% endhighlight %}

Striped rows

Use .table-striped to add zebra-striping to any table row within the <tbody>.

Cross-browser compatibility

Striped tables are styled via the :nth-child CSS selector, which is not available in Internet Explorer 8.

# First Name Last Name Username
1 Mark Otto @mdo
2 Jacob Thornton @fat
3 Larry the Bird @twitter
{% highlight html %} ...
{% endhighlight %}

Bordered table

Add .table-bordered for borders on all sides of the table and cells.

# First Name Last Name Username
1 Mark Otto @mdo
Mark Otto @TwBootstrap
2 Jacob Thornton @fat
3 Larry the Bird @twitter
{% highlight html %} ...
{% endhighlight %}

Hover rows

Add .table-hover to enable a hover state on table rows within a <tbody>.

# First Name Last Name Username
1 Mark Otto @mdo
2 Jacob Thornton @fat
3 Larry the Bird @twitter
{% highlight html %} ...
{% endhighlight %}

Condensed table

Add .table-condensed to make tables more compact by cutting cell padding in half.

# First Name Last Name Username
1 Mark Otto @mdo
2 Jacob Thornton @fat
3 Larry the Bird @twitter
{% highlight html %} ...
{% endhighlight %}

Contextual classes

Use contextual classes to color table rows or individual cells.

Class Description
.active Applies the hover color to a particular row or cell
.success Indicates a successful or positive action
.info Indicates a neutral informative change or action
.warning Indicates a warning that might need attention
.danger Indicates a dangerous or potentially negative action
# Column heading Column heading Column heading
1 Column content Column content Column content
2 Column content Column content Column content
3 Column content Column content Column content
4 Column content Column content Column content
5 Column content Column content Column content
6 Column content Column content Column content
7 Column content Column content Column content
8 Column content Column content Column content
9 Column content Column content Column content
{% highlight html %} ... ... ... ... ... ... ... ... ... ... {% endhighlight %}

Responsive tables

Create responsive tables by wrapping any .table in .table-responsive to make them scroll horizontally up to small devices (under 768px). When viewing on anything larger than 768px wide, you will not see any difference in these tables.

# Table heading Table heading Table heading Table heading Table heading Table heading
1 Table cell Table cell Table cell Table cell Table cell Table cell
2 Table cell Table cell Table cell Table cell Table cell Table cell
3 Table cell Table cell Table cell Table cell Table cell Table cell
# Table heading Table heading Table heading Table heading Table heading Table heading
1 Table cell Table cell Table cell Table cell Table cell Table cell
2 Table cell Table cell Table cell Table cell Table cell Table cell
3 Table cell Table cell Table cell Table cell Table cell Table cell
{% highlight html %}
...
{% endhighlight %}

Forms

Basic example

Individual form controls automatically receive some global styling. All textual <input>, <textarea>, and <select> elements with .form-control are set to width: 100%; by default. Wrap labels and controls in .form-group for optimum spacing.

Example block-level help text here.

{% highlight html %}

Example block-level help text here.

{% endhighlight %}

Don't mix form groups with input groups

Do not mix form groups directly with input groups. Instead, nest the input group inside of the form group.

Inline form

Add .form-inline to your <form> for left-aligned and inline-block controls. This only applies to forms within viewports that are at least 768px wide.

Requires custom widths

Inputs, selects, and textareas are 100% wide by default in Bootstrap. To use the inline form, you'll have to set a width on the form controls used within.

Always add labels

Screen readers will have trouble with your forms if you don't include a label for every input. For these inline forms, you can hide the labels using the .sr-only class.

{% highlight html %}
{% endhighlight %}

Horizontal form

Use Bootstrap's predefined grid classes to align labels and groups of form controls in a horizontal layout by adding .form-horizontal to the form. Doing so changes .form-groups to behave as grid rows, so no need for .row.

{% highlight html %}
{% endhighlight %}

Supported controls

Examples of standard form controls supported in an example form layout.

Inputs

Most common form control, text-based input fields. Includes support for all HTML5 types: text, password, datetime, datetime-local, date, month, time, week, number, email, url, search, tel, and color.

Type declaration required

Inputs will only be fully styled if their type is properly declared.

{% highlight html %} {% endhighlight %}

Input groups

To add integrated text or buttons before and/or after any text-based <input>, check out the input group component.

Textarea

Form control which supports multiple lines of text. Change rows attribute as necessary.

{% highlight html %} {% endhighlight %}

Checkboxes and radios

Checkboxes are for selecting one or several options in a list while radios are for selecting one option from many.

Default (stacked)


{% highlight html %}
{% endhighlight %}

Inline checkboxes

Use the .checkbox-inline or .radio-inline classes on a series of checkboxes or radios for controls that appear on the same line.

{% highlight html %} {% endhighlight %}

Selects

Use the default option, or add multiple to show multiple options at once.


{% highlight html %} {% endhighlight %}

Static control

When you need to place plain text next to a form label within a horizontal form, use the .form-control-static class on a <p>.

email@example.com

{% highlight html %}

email@example.com

{% endhighlight %}

Input focus

We remove the default outline styles on some form controls and apply a box-shadow in its place for :focus.

Demo :focus state

The above example input uses custom styles in our documentation to demonstrate the :focus state on a .form-control.

Disabled inputs

Add the disabled attribute on an input to prevent user input and trigger a slightly different look.

{% highlight html %} {% endhighlight %}

Disabled fieldsets

Add the disabled attribute to a <fieldset> to disable all the controls within the <fieldset> at once.

Link functionality of <a> not impacted

This class will only change the appearance of <a class="btn btn-default"> buttons, not their functionality. Use custom JavaScript to disable links here.

Cross-browser compatibility

While Bootstrap will apply these styles in all browsers, Internet Explorer 9 and below don't actually support the disabled attribute on a <fieldset>. Use custom JavaScript to disable the fieldset in these browsers.

{% highlight html %}
{% endhighlight %}

Validation states

Bootstrap includes validation styles for error, warning, and success states on form controls. To use, add .has-warning, .has-error, or .has-success to the parent element. Any .control-label, .form-control, and .help-block within that element will receive the validation styles.

{% highlight html %}
{% endhighlight %}

With optional icons

You can also add optional feedback icons with the addition of an extra class and the right icon.

Icons and input groups

When using the feedback icons, be aware that manual positioning may be required for input groups with an add-on on the right. Adjust the right: 0; to an appropriate pixel value depending on the width of your addon.

{% highlight html %}
{% endhighlight %}

Optional icons also work on horizontal and inline forms.

{% highlight html %}
{% endhighlight %}
{% highlight html %}
{% endhighlight %}

Control sizing

Set heights using classes like .input-lg, and set widths using grid column classes like .col-lg-*.

Height sizing

Create taller or shorter form controls that match button sizes.

{% highlight html %} {% endhighlight %}

Column sizing

Wrap inputs in grid columns, or any custom parent element, to easily enforce desired widths.

{% highlight html %}
{% endhighlight %}

Help text

Block level help text for form controls.

A block of help text that breaks onto a new line and may extend beyond one line.
{% highlight html %} A block of help text that breaks onto a new line and may extend beyond one line. {% endhighlight %}

Buttons

Options

Use any of the available button classes to quickly create a styled button.

{% highlight html %} {% endhighlight %}

Sizes

Fancy larger or smaller buttons? Add .btn-lg, .btn-sm, or .btn-xs for additional sizes.

{% highlight html %}

{% endhighlight %}

Create block level buttons—those that span the full width of a parent— by adding .btn-block.

{% highlight html %} {% endhighlight %}

Active state

Buttons will appear pressed (with a darker background, darker border, and inset shadow) when active. For <button> elements, this is done via :active. For <a> elements, it's done with .active. However, you may use .active on <button>s should you need to replicate the active state progammatically.

Button element

No need to add :active as it's a pseudo-class, but if you need to force the same appearance, go ahead and add .active.

{% highlight html %} {% endhighlight %}

Anchor element

Add the .active class to <a> buttons.

Primary link Link

{% highlight html %} Primary link Link {% endhighlight %}

Disabled state

Make buttons look unclickable by fading them back 50%.

Button element

Add the disabled attribute to <button> buttons.

{% highlight html %} {% endhighlight %}

Cross-browser compatibility

If you add the disabled attribute to a <button>, Internet Explorer 9 and below will render text gray with a nasty text-shadow that we cannot fix.

Anchor element

Add the .disabled class to <a> buttons.

Primary link Link

{% highlight html %} Primary link Link {% endhighlight %}

We use .disabled as a utility class here, similar to the common .active class, so no prefix is required.

Link functionality not impacted

This class will only change the <a>'s appearance, not its functionality. Use custom JavaScript to disable links here.

Context-specific usage

While button classes can be used on <a> and <button> elements, only <button> elements are supported within our nav and navbar components.

Button tags

Use the button classes on an <a>, <button>, or <input> element.

Link
{% highlight html %} Link {% endhighlight %}

Cross-browser rendering

As a best practice, we highly recommend using the <button> element whenever possible to ensure matching cross-browser rendering.

Among other things, there's a Firefox bug that prevents us from setting the line-height of <input>-based buttons, causing them to not exactly match the height of other buttons on Firefox.

Images

Responsive images

Images in Bootstrap 3 can be made responsive-friendly via the addition of the .img-responsive class. This applies max-width: 100%; and height: auto; to the image so that it scales nicely to the parent element.

{% highlight html %} Responsive image {% endhighlight %}

Image shapes

Add classes to an <img> element to easily style images in any project.

Cross-browser compatibility

Keep in mind that Internet Explorer 8 lacks support for rounded corners.

A generic square placeholder image with rounded corners A generic square placeholder image where only the portion within the circle circumscribed about said square is visible A generic square placeholder image with a white border around it, making it resemble a photograph taken with an old instant camera
{% highlight html %} ... ... ... {% endhighlight %}

Helper classes

Contextual colors

Convey meaning through color with a handful of emphasis utility classes. These may also be applied to links and will darken on hover just like our default link styles.

Fusce dapibus, tellus ac cursus commodo, tortor mauris nibh.

Nullam id dolor id nibh ultricies vehicula ut id elit.

Duis mollis, est non commodo luctus, nisi erat porttitor ligula.

Maecenas sed diam eget risus varius blandit sit amet non magna.

Etiam porta sem malesuada magna mollis euismod.

Donec ullamcorper nulla non metus auctor fringilla.

{% highlight html %}

...

...

...

...

...

...

{% endhighlight %}

Dealing with specificity

Sometimes emphasis classes cannot be applied due to the specificity of another selector. In most cases, a sufficient workaround is to wrap your text in a <span> with the class.

Contextual backgrounds

Similar to the contextual text color classes, easily set the background of an element to any contextual class. Anchor components will darken on hover, just like the text classes.

Nullam id dolor id nibh ultricies vehicula ut id elit.

Duis mollis, est non commodo luctus, nisi erat porttitor ligula.

Maecenas sed diam eget risus varius blandit sit amet non magna.

Etiam porta sem malesuada magna mollis euismod.

Donec ullamcorper nulla non metus auctor fringilla.

{% highlight html %}

...

...

...

...

...

{% endhighlight %}

Close icon

Use the generic close icon for dismissing content like modals and alerts.

{% highlight html %} {% endhighlight %}

Carets

Use carets to indicate dropdown functionality and direction. Note that the default caret will reverse automatically in dropup menus.

{% highlight html %} {% endhighlight %}

Quick floats

Float an element to the left or right with a class. !important is included to avoid specificity issues. Classes can also be used as mixins.

{% highlight html %}
...
...
{% endhighlight %} {% highlight scss %} // Classes .pull-left { float: left !important; } .pull-right { float: right !important; } // Usage as mixins .element { .pull-left(); } .another-element { .pull-right(); } {% endhighlight %}

Not for use in navbars

To align components in navbars with utility classes, use .navbar-left or .navbar-right instead. See the navbar docs for details.

Center content blocks

Set an element to display: block and center via margin. Available as a mixin and class.

{% highlight html %}
...
{% endhighlight %} {% highlight scss %} // Classes .center-block { display: block; margin-left: auto; margin-right: auto; } // Usage as mixins .element { .center-block(); } {% endhighlight %}

Clearfix

Clear the float on any element with the .clearfix class. Utilizes the micro clearfix as popularized by Nicolas Gallagher. Can also be used as a mixin.

{% highlight html %}
...
{% endhighlight %} {% highlight scss %} // Mixin itself .clearfix() { &:before, &:after { content: " "; display: table; } &:after { clear: both; } } // Usage as a Mixin .element { .clearfix(); } {% endhighlight %}

Showing and hiding content

Force an element to be shown or hidden (including for screen readers) with the use of .show and .hidden classes. These classes use !important to avoid specificity conflicts, just like the quick floats. They are only available for block level toggling. They can also be used as mixins.

.hide is available, but it does not always affect screen readers and is deprecated as of v3.0.1. Use .hidden or .sr-only instead.

Furthermore, .invisible can be used to toggle only the visibility of an element, meaning its display is not modified and the element can still affect the flow of the document.

{% highlight html %}
...
{% endhighlight %} {% highlight scss %} // Classes .show { display: block !important; } .hidden { display: none !important; visibility: hidden !important; } .invisible { visibility: hidden; } // Usage as mixins .element { .show(); } .another-element { .hidden(); } {% endhighlight %}

Screen reader content

Hide an element to all devices except screen readers with .sr-only. Necessary for following accessibility best practices. Can also be used as a mixin.

{% highlight html %} Skip to main content {% endhighlight %} {% highlight scss %} // Usage as a Mixin .skip-navigation { .sr-only(); } {% endhighlight %}

Image replacement

Utilize the .text-hide class or mixin to help replace an element's text content with a background image.

{% highlight html %}

Custom heading

{% endhighlight %} {% highlight scss %} // Usage as a Mixin .heading { .text-hide(); } {% endhighlight %}

Responsive utilities

For faster mobile-friendly development, use these utility classes for showing and hiding content by device via media query. Also included are utility classes for toggling content when printed.

Try to use these on a limited basis and avoid creating entirely different versions of the same site. Instead, use them to complement each device's presentation. Responsive utilities are currently only available for block and table toggling. Use with inline and table elements is currently not supported.

Available classes

Use a single or combination of the available classes for toggling content across viewport breakpoints.

Extra small devices Phones (<768px) Small devices Tablets (≥768px) Medium devices Desktops (≥992px) Large devices Desktops (≥1200px)
.visible-xs Visible
.visible-sm Visible
.visible-md Visible
.visible-lg Visible
.hidden-xs Visible Visible Visible
.hidden-sm Visible Visible Visible
.hidden-md Visible Visible Visible
.hidden-lg Visible Visible Visible

Print classes

Similar to the regular responsive classes, use these for toggling content for print.

Class Browser Print
.visible-print Visible
.hidden-print Visible

Test cases

Resize your browser or load on different devices to test the responsive utility classes.

Visible on...

Green checkmarks indicate the element is visible in your current viewport.

✔ Visible on x-small
✔ Visible on small
Medium ✔ Visible on medium
✔ Visible on large
✔ Visible on x-small and small
✔ Visible on medium and large
✔ Visible on x-small and medium
✔ Visible on small and large
✔ Visible on x-small and large
✔ Visible on small and medium

Hidden on...

Here, green checkmarks also indicate the element is hidden in your current viewport.

✔ Hidden on x-small
✔ Hidden on small
Medium ✔ Hidden on medium
✔ Hidden on large
✔ Hidden on x-small and small
✔ Hidden on medium and large
✔ Hidden on x-small and medium
✔ Hidden on small and large
✔ Hidden on x-small and large
✔ Hidden on small and medium

Using Less

Bootstrap's CSS is built on Less, a preprocessor with additional functionality like variables, mixins, and functions for compiling CSS. Those looking to use the source Less files instead of our compiled CSS files can make use of the numerous variables and mixins we use throughout the framework.

Grid variables and mixins are covered within the Grid system section.

Compiling Bootstrap

Bootstrap can be used in at least two ways: with the compiled CSS or with the source Less files. To compile the Less files, visit the README for how to setup your development environment to run the necessary commands.

Third party compilation tools may work with Bootstrap, but they are not supported by our core team.

Variables

Variables are used throughout the entire project as a way to centralize and share commonly used values like colors, spacing, or font stacks. For a complete breakdown, please see the Customizer.

Colors

Easily make use of two color schemes: grayscale and semantic. Grayscale colors provide quick access to commonly used shades of black while semantic include various colors assigned to meaningful contextual values.

{% highlight scss %} @gray-darker: lighten(#000, 13.5%); // #222 @gray-dark: lighten(#000, 20%); // #333 @gray: lighten(#000, 33.5%); // #555 @gray-light: lighten(#000, 60%); // #999 @gray-lighter: lighten(#000, 93.5%); // #eee {% endhighlight %}
{% highlight scss %} @brand-primary: #428bca; @brand-success: #5cb85c; @brand-info: #5bc0de; @brand-warning: #f0ad4e; @brand-danger: #d9534f; {% endhighlight %}

Use any of these color variables as they are or reassign them to more meaningful variables for your project.

{% highlight scss %} // Use as-is .masthead { background-color: @brand-primary; } // Reassigned variables in Less @alert-message-background: @brand-info; .alert { background-color: @alert-message-background; } {% endhighlight %}

Scaffolding

A handful of variables for quickly customizing key elements of your site's skeleton.

{% highlight scss %} // Scaffolding @body-bg: #fff; @text-color: @black-50; {% endhighlight %}

Easily style your links with the right color with only one value.

{% highlight scss %} // Variables @link-color: @brand-primary; @link-color-hover: darken(@link-color, 15%); // Usage a { color: @link-color; text-decoration: none; &:hover { color: @link-color-hover; text-decoration: underline; } } {% endhighlight %}

Note that the @link-color-hover uses a function, another awesome tool from Less, to automagically create the right hover color. You can use darken, lighten, saturate, and desaturate.

Typography

Easily set your type face, text size, leading, and more with a few quick variables. Bootstrap makes use of these as well to provide easy typographic mixins.

{% highlight scss %} @font-family-sans-serif: "Helvetica Neue", Helvetica, Arial, sans-serif; @font-family-serif: Georgia, "Times New Roman", Times, serif; @font-family-monospace: Menlo, Monaco, Consolas, "Courier New", monospace; @font-family-base: @font-family-sans-serif; @font-size-base: 14px; @font-size-large: ceil((@font-size-base * 1.25)); // ~18px @font-size-small: ceil((@font-size-base * 0.85)); // ~12px @font-size-h1: floor((@font-size-base * 2.6)); // ~36px @font-size-h2: floor((@font-size-base * 2.15)); // ~30px @font-size-h3: ceil((@font-size-base * 1.7)); // ~24px @font-size-h4: ceil((@font-size-base * 1.25)); // ~18px @font-size-h5: @font-size-base; @font-size-h6: ceil((@font-size-base * 0.85)); // ~12px @line-height-base: 1.428571429; // 20/14 @line-height-computed: floor((@font-size-base * @line-height-base)); // ~20px @headings-font-family: inherit; @headings-font-weight: 500; @headings-line-height: 1.1; @headings-color: inherit; {% endhighlight %}

Icons

Two quick variables for customizing the location and filename of your icons.

{% highlight scss %} @icon-font-path: "../fonts/"; @icon-font-name: "glyphicons-halflings-regular"; {% endhighlight %}

Components

Components throughout Bootstrap make use of some default variables for setting common values. Here are the most commonly used.

{% highlight scss %} @padding-base-vertical: 6px; @padding-base-horizontal: 12px; @padding-large-vertical: 10px; @padding-large-horizontal: 16px; @padding-small-vertical: 5px; @padding-small-horizontal: 10px; @padding-xs-vertical: 1px; @padding-xs-horizontal: 5px; @line-height-large: 1.33; @line-height-small: 1.5; @border-radius-base: 4px; @border-radius-large: 6px; @border-radius-small: 3px; @component-active-color: #fff; @component-active-bg: @brand-primary; @caret-width-base: 4px; @caret-width-large: 5px; {% endhighlight %}

Vendor mixins

Vendor mixins are mixins to help support multiple browsers by including all relevant vendor prefixes in your compiled CSS.

Box-sizing

Reset your components' box model with a single mixin. For context, see this helpful article from Mozilla.

{% highlight scss %} .box-sizing(@box-model) { -webkit-box-sizing: @box-model; // Safari <= 5 -moz-box-sizing: @box-model; // Firefox <= 19 box-sizing: @box-model; } {% endhighlight %}

Rounded corners

Today all modern browsers support the non-prefixed border-radius property. As such, there is no .border-radius() mixin, but Bootstrap does include shortcuts for quickly rounding two corners on a particular side of an object.

{% highlight scss %} .border-top-radius(@radius) { border-top-right-radius: @radius; border-top-left-radius: @radius; } .border-right-radius(@radius) { border-bottom-right-radius: @radius; border-top-right-radius: @radius; } .border-bottom-radius(@radius) { border-bottom-right-radius: @radius; border-bottom-left-radius: @radius; } .border-left-radius(@radius) { border-bottom-left-radius: @radius; border-top-left-radius: @radius; } {% endhighlight %}

Box (Drop) shadows

If your target audience is using the latest and greatest browsers and devices, be sure to just use the box-shadow property on its own. If you need support for older Android (pre-v4) and iOS devices (pre-iOS 5), use the deprecated mixin to pick up the required -webkit prefix.

The mixin is deprecated as of v3.1.0, since Bootstrap doesn't officially support the outdated platforms that don't support the standard property. To preserve backwards-compatibility, Bootstrap will continue to use the mixin internally until Bootstrap v4.

Be sure to use rgba() colors in your box shadows so they blend as seamlessly as possible with backgrounds.

{% highlight scss %} .box-shadow(@shadow: 0 1px 3px rgba(0,0,0,.25)) { -webkit-box-shadow: @shadow; // iOS <4.3 & Android <4.1 box-shadow: @shadow; } {% endhighlight %}

Transitions

Three mixins for flexibility. Set all transition information with one, or specify a separate delay and duration as needed.

{% highlight scss %} .transition(@transition) { -webkit-transition: @transition; transition: @transition; } .transition-property(@transition-property) { -webkit-transition-property: @transition-property; transition-property: @transition-property; } .transition-delay(@transition-delay) { -webkit-transition-delay: @transition-delay; transition-delay: @transition-delay; } .transition-duration(@transition-duration) { -webkit-transition-duration: @transition-duration; transition-duration: @transition-duration; } .transition-transform(@transition) { -webkit-transition: -webkit-transform @transition; -moz-transition: -moz-transform @transition; -o-transition: -o-transform @transition; transition: transform @transition; } {% endhighlight %}

Transformations

Rotate, scale, translate (move), or skew any object.

{% highlight scss %} .rotate(@degrees) { -webkit-transform: rotate(@degrees); -ms-transform: rotate(@degrees); // IE9 only transform: rotate(@degrees); } .scale(@ratio; @ratio-y...) { -webkit-transform: scale(@ratio, @ratio-y); -ms-transform: scale(@ratio, @ratio-y); // IE9 only transform: scale(@ratio, @ratio-y); } .translate(@x; @y) { -webkit-transform: translate(@x, @y); -ms-transform: translate(@x, @y); // IE9 only transform: translate(@x, @y); } .skew(@x; @y) { -webkit-transform: skew(@x, @y); -ms-transform: skewX(@x) skewY(@y); // See https://github.com/twbs/bootstrap/issues/4885; IE9+ transform: skew(@x, @y); } .translate3d(@x; @y; @z) { -webkit-transform: translate3d(@x, @y, @z); transform: translate3d(@x, @y, @z); } .rotateX(@degrees) { -webkit-transform: rotateX(@degrees); -ms-transform: rotateX(@degrees); // IE9 only transform: rotateX(@degrees); } .rotateY(@degrees) { -webkit-transform: rotateY(@degrees); -ms-transform: rotateY(@degrees); // IE9 only transform: rotateY(@degrees); } .perspective(@perspective) { -webkit-perspective: @perspective; -moz-perspective: @perspective; perspective: @perspective; } .perspective-origin(@perspective) { -webkit-perspective-origin: @perspective; -moz-perspective-origin: @perspective; perspective-origin: @perspective; } .transform-origin(@origin) { -webkit-transform-origin: @origin; -moz-transform-origin: @origin; -ms-transform-origin: @origin; // IE9 only transform-origin: @origin; } {% endhighlight %}

Animations

A single mixin for using all of CSS3's animation properties in one declaration and other mixins for individual properties.

{% highlight scss %} .animation(@animation) { -webkit-animation: @animation; animation: @animation; } .animation-name(@name) { -webkit-animation-name: @name; animation-name: @name; } .animation-duration(@duration) { -webkit-animation-duration: @duration; animation-duration: @duration; } .animation-timing-function(@timing-function) { -webkit-animation-timing-function: @timing-function; animation-timing-function: @timing-function; } .animation-delay(@delay) { -webkit-animation-delay: @delay; animation-delay: @delay; } .animation-iteration-count(@iteration-count) { -webkit-animation-iteration-count: @iteration-count; animation-iteration-count: @iteration-count; } .animation-direction(@direction) { -webkit-animation-direction: @direction; animation-direction: @direction; } {% endhighlight %}

Opacity

Set the opacity for all browsers and provide a filter fallback for IE8.

{% highlight scss %} .opacity(@opacity) { opacity: @opacity; // IE8 filter @opacity-ie: (@opacity * 100); filter: ~"alpha(opacity=@{opacity-ie})"; } {% endhighlight %}

Placeholder text

Provide context for form controls within each field.

{% highlight scss %} .placeholder(@color: @input-color-placeholder) { &:-moz-placeholder { color: @color; } // Firefox 4-18 &::-moz-placeholder { color: @color; } // Firefox 19+ &:-ms-input-placeholder { color: @color; } // Internet Explorer 10+ &::-webkit-input-placeholder { color: @color; } // Safari and Chrome } {% endhighlight %}

Columns

Generate columns via CSS within a single element.

{% highlight scss %} .content-columns(@width; @count; @gap) { -webkit-column-width: @width; -moz-column-width: @width; column-width: @width; -webkit-column-count: @count; -moz-column-count: @count; column-count: @count; -webkit-column-gap: @gap; -moz-column-gap: @gap; column-gap: @gap; } {% endhighlight %}

Gradients

Easily turn any two colors into a background gradient. Get more advanced and set a direction, use three colors, or use a radial gradient. With a single mixin you get all the prefixed syntaxes you'll need.

{% highlight scss %} #gradient > .vertical(#333; #000); #gradient > .horizontal(#333; #000); #gradient > .radial(#333; #000); {% endhighlight %}

You can also specify the angle of a standard two-color, linear gradient:

{% highlight scss %} #gradient > .directional(#333; #000; 45deg); {% endhighlight %}

If you need a barber-stripe style gradient, that's easy, too. Just specify a single color and we'll overlay a translucent white stripe.

{% highlight scss %} #gradient > .striped(#333; #000; 45deg); {% endhighlight %}

Up the ante and use three colors instead. Set the first color, the second color, the second color's color stop (a decimal value like 0.25), and the third color with these mixins:

{% highlight scss %} #gradient > .vertical-three-colors(#777; #333; .25; #000); #gradient > .horizontal-three-colors(#777; #333; .25; #000); {% endhighlight %}

Heads up! Should you ever need to remove a gradient, be sure to remove any IE-specific filter you may have added. You can do that by using the .reset-filter() mixin alongside background-image: none;.

Utility mixins

Utility mixins are mixins that combine otherwise unrelated CSS properties to achieve a specific goal or task.

Clearfix

Forget adding class="clearfix" to any element and instead add the .clearfix() mixin where appropriate. Uses the micro clearfix from Nicolas Gallager.

{% highlight scss %} // Mixin .clearfix() { &:before, &:after { content: " "; display: table; } &:after { clear: both; } } // Usage .container { .clearfix(); } {% endhighlight %}

Horizontal centering

Quickly center any element within its parent. Requires width or max-width to be set.

{% highlight scss %} // Mixin .center-block() { display: block; margin-left: auto; margin-right: auto; } // Usage .container { width: 940px; .center-block(); } {% endhighlight %}

Sizing helpers

Specify the dimensions of an object more easily.

{% highlight scss %} // Mixins .size(@width; @height) { width: @width; height: @height; } .square(@size) { .size(@size; @size); } // Usage .image { .size(400px; 300px); } .avatar { .square(48px); } {% endhighlight %}

Resizable textareas

Easily configure the resize options for any textarea, or any other element. Defaults to normal browser behavior (both).

{% highlight scss %} .resizable(@direction: both) { // Options: horizontal, vertical, both resize: @direction; // Safari fix overflow: auto; } {% endhighlight %}

Truncating text

Easily truncate text with an ellipsis with a single mixin. Requires element to be block or inline-block level.

{% highlight scss %} // Mixin .text-overflow() { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; } // Usage .branch-name { display: inline-block; max-width: 200px; .text-overflow(); } {% endhighlight %}

Retina images

Specify two image paths and the @1x image dimensions, and Bootstrap will provide an @2x media query. If you have many images to serve, consider writing your retina image CSS manually in a single media query.

{% highlight scss %} .img-retina(@file-1x; @file-2x; @width-1x; @height-1x) { background-image: url("@{file-1x}"); @media only screen and (-webkit-min-device-pixel-ratio: 2), only screen and ( min--moz-device-pixel-ratio: 2), only screen and ( -o-min-device-pixel-ratio: 2/1), only screen and ( min-device-pixel-ratio: 2), only screen and ( min-resolution: 192dpi), only screen and ( min-resolution: 2dppx) { background-image: url("@{file-2x}"); background-size: @width-1x @height-1x; } } // Usage .jumbotron { .img-retina("/img/bg-1x.png", "/img/bg-2x.png", 100px, 100px); } {% endhighlight %}

Using Sass

While Bootstrap is built on Less, it also has an official Sass port. We maintain it in a separate GitHub repository and handle updates with a conversion script.

What's included

Since the Sass port has a separate repo and serves a slightly different audience, the contents of the project differ greatly from the main Bootstrap project. This ensures the Sass port is as compatible with as many Sass-based systems as possible.

Path Description
lib/ Ruby gem code (Sass configuration, Rails and Compass integrations)
tasks/ Converter scripts (turning upstream Less to Sass)
test/ Compilation tests
templates/ Compass package manifest
vendor/assets/ Sass, JavaScript, and font files
Rakefile Internal tasks, such as rake and convert

Visit the Sass port's GitHub repository to see these files in action.

Installation

For information on how to install and use Bootstrap for Sass, consult the GitHub repository readme. It's the most up to date source and includes information for use with Rails, Compass, and standard Sass projects.

Bootstrap for Sass