* Add dark mode to docs * Minor fix: missing space indentation * Minor fix: revert utilities/z-index added-in modification * Remove prev: and next: from doc because extracted to another PR * Use .bg-body-tertiary in all Utilities > Overflow examples * fix example * Fix up spacing examples * Update box-shadow Sass variables and utilities to auto-adjust to color modes * Remove unused docs class * Refactor form styles to use CSS variable for background images on .form-check and .form-switch * Fix docs selector * Rename shortcut for clarity * Heading consistency * Reintroduce missing 4th grid item in Utilities > Spacing example * Fix bundlewatch * .bd-callout* rendering is OK so removing comments in the code * Update scss/_utilities.scss Co-authored-by: Julien Déramond <julien.deramond@orange.com> * Fix gutters example styling * Fix text colors on background utils docs * redesign and fix up position marker example, which doesn't show nicely in darkmode but at least isn't broken * fix some color utils examples * Deprecate mixin notice * Deprecate notice for list-group-item-variant() mixin * Revamp new link CSS vars * Use map-keys in some each Sass files * Remove list-group-item-variant mixin ref in sass loop desc * Display CSS vars scoped to our built-in dark mode * Revert previous commit * Fix list group variant link * Fix typo * Remove imports of alert/list-group mixins in scss/_mixins.scss * Small formatting + comments removal in scss/_content.scss * Fix alert links colors * fix dropdown border-radius mixin * fix link color and underline again, this time using CSS var override for color var and fallback value for the underline * fix colors on docs navbar for dark mode * remove two changes * missing ref * another link underline fix, just use sass vars for link decoration for now * missing color bg docs, plus move dropdown override to scss * more changes from review * fix some examples, drop unused docs navbar styles, update docs navbar color mode to use mixin * Few fixes around type - Restored CSS variable for color on headings, this time with a fallback value - In conjunction, restored and wrapped the default CSS var with a null value check - Split headings and paragraphs docs in Reboot, elaborated on them * Restyle custom details > summary element in docs * Rewrite some migration docs * fix form checks * Fix up some navbar styling, tweak docs callout * Fix select images, mostly for validation styling * Clean up some migration notes, document some new form control CSS vars, mention new variables-dark in sass docs * Update site/content/docs/5.2/components/scrollspy.md Co-authored-by: Julien Déramond <julien.deramond@orange.com> * Apply suggestions from code review Co-authored-by: Julien Déramond <julien.deramond@orange.com> * mention form control css vars in migration guide * Tweak grid and flex docs background examples * clarify some docs * fix some more things Co-authored-by: Julien Déramond <juderamond@gmail.com> Co-authored-by: Julien Déramond <julien.deramond@orange.com>
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layout, title, description, group, aliases, toc
| layout | title | description | group | aliases | toc |
|---|---|---|---|---|---|
| docs | Reboot | Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon. | content | /docs/5.2/content/ | true |
Approach
Reboot builds upon Normalize, providing many HTML elements with somewhat opinionated styles using only element selectors. Additional styling is done only with classes. For example, we reboot some <table> styles for a simpler baseline and later provide .table, .table-bordered, and more.
Here are our guidelines and reasons for choosing what to override in Reboot:
- Update some browser default values to use
rems instead ofems for scalable component spacing. - Avoid
margin-top. Vertical margins can collapse, yielding unexpected results. More importantly though, a single direction ofmarginis a simpler mental model. - For easier scaling across device sizes, block elements should use
rems formargins. - Keep declarations of
font-related properties to a minimum, usinginheritwhenever possible.
CSS variables
{{< added-in "5.2.0" >}}
With v5.1.1, we standardized our required @imports across all our CSS bundles (including bootstrap.css, bootstrap-reboot.css, and bootstrap-grid.css) to include _root.scss. This adds :root level CSS variables to all bundles, regardless of how many of them are used in that bundle. Ultimately Bootstrap 5 will continue to see more [CSS variables]({{< docsref "/customize/css-variables" >}}) added over time, in order to provide more real-time customization without the need to always recompile Sass. Our approach is to take our source Sass variables and transform them into CSS variables. That way, even if you don't use CSS variables, you still have all the power of Sass. This is still in-progress and will take time to fully implement.
For example, consider these :root CSS variables for common <body> styles:
{{< scss-docs name="root-body-variables" file="scss/_root.scss" >}}
In practice, those variables are then applied in Reboot like so:
{{< scss-docs name="reboot-body-rules" file="scss/_reboot.scss" >}}
Which allows you to make real-time customizations however you like:
<body style="--bs-body-color: #333;">
<!-- ... -->
</body>
Page defaults
The <html> and <body> elements are updated to provide better page-wide defaults. More specifically:
- The
box-sizingis globally set on every element—including*::beforeand*::after, toborder-box. This ensures that the declared width of element is never exceeded due to padding or border.- No base
font-sizeis declared on the<html>, but16pxis assumed (the browser default).font-size: 1remis applied on the<body>for easy responsive type-scaling via media queries while respecting user preferences and ensuring a more accessible approach. This browser default can be overridden by modifying the$font-size-rootvariable.
- No base
- The
<body>also sets a globalfont-family,font-weight,line-height, andcolor. This is inherited later by some form elements to prevent font inconsistencies. - For safety, the
<body>has a declaredbackground-color, defaulting to#fff.
Native font stack
Bootstrap utilizes a "native font stack" or "system font stack" for optimum text rendering on every device and OS. These system fonts have been designed specifically with today's devices in mind, with improved rendering on screens, variable font support, and more. Read more about native font stacks in this Smashing Magazine article.
$font-family-sans-serif:
// Cross-platform generic font family (default user interface font)
system-ui,
// Safari for macOS and iOS (San Francisco)
-apple-system,
// Windows
"Segoe UI",
// Android
Roboto,
// older macOS and iOS
"Helvetica Neue"
// Linux
"Noto Sans",
"Liberation Sans",
// Basic web fallback
Arial,
// Sans serif fallback
sans-serif,
// Emoji fonts
"Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji" !default;
Note that because the font stack includes emoji fonts, many common symbol/dingbat Unicode characters will be rendered as multicolored pictographs. Their appearance will vary, depending on the style used in the browser/platform's native emoji font, and they won't be affected by any CSS color styles.
This font-family is applied to the <body> and automatically inherited globally throughout Bootstrap. To switch the global font-family, update $font-family-base and recompile Bootstrap.
Headings
All heading elements—<h1>—<h6> have their margin-top removed, margin-bottom: .5rem set, and line-height tightened. While headings inherit their color by default, you can also override it via optional CSS variable, --bs-heading-color.
{{< bs-table "table" >}}
| Heading | Example |
|---|---|
<h1></h1> |
h1. Bootstrap heading |
<h2></h2> |
h2. Bootstrap heading |
<h3></h3> |
h3. Bootstrap heading |
<h4></h4> |
h4. Bootstrap heading |
<h5></h5> |
h5. Bootstrap heading |
<h6></h6> |
h6. Bootstrap heading |
| {{< /bs-table >}} |
Paragraphs
All <p> elements have their margin-top removed and margin-bottom: 1rem set for easy spacing.
{{< example >}}
This is an example paragraph.
{{< /example >}}Links
Links have a default color and underline applied. While links change on :hover, they don't change based on whether someone :visited the link. They also receive no special :focus styles.
{{< example >}} This is an example link {{< /example >}}
As of v5.3.x, link color is set using rgba() and new -rgb CSS variables, allowing for easy customization of link color opacity. Change the link color opacity with the --bs-link-opacity CSS variable:
{{< example >}} This is an example link {{< /example >}}
Placeholder links—those without an href—are targeted with a more specific selector and have their color and text-decoration reset to their default values.
{{< example >}} This is a placeholder link {{< /example >}}
Horizontal rules
The <hr> element has been simplified. Similar to browser defaults, <hr>s are styled via border-top, have a default opacity: .25, and automatically inherit their border-color via color, including when color is set via the parent. They can be modified with text, border, and opacity utilities.
{{< example >}}
{{< /example >}}
Lists
All lists—<ul>, <ol>, and <dl>—have their margin-top removed and a margin-bottom: 1rem. Nested lists have no margin-bottom. We've also reset the padding-left on <ul> and <ol> elements.
- Here's an ordered list
- With a few list items
- It has the same overall look
- As the previous unordered list {{< /markdown >}}
For simpler styling, clear hierarchy, and better spacing, description lists have updated margins. <dd>s reset margin-left to 0 and add margin-bottom: .5rem. <dt>s are bolded.
- Description lists
- A description list is perfect for defining terms.
- Term
- Definition for the term.
- A second definition for the same term.
- Another term
- Definition for this other term.
Inline code
Wrap inline snippets of code with <code>. Be sure to escape HTML angle brackets.
{{< example >}}
For example, <section> should be wrapped as inline.
{{< /example >}}
Code blocks
Use <pre>s for multiple lines of code. Once again, be sure to escape any angle brackets in the code for proper rendering. The <pre> element is reset to remove its margin-top and use rem units for its margin-bottom.
{{< example >}}
<p>Sample text here...</p>
<p>And another line of sample text here...</p>
{{< /example >}}
Variables
For indicating variables use the <var> tag.
{{< example >}} y = mx + b {{< /example >}}
User input
Use the <kbd> to indicate input that is typically entered via keyboard.
{{< example >}}
To switch directories, type cd followed by the name of the directory.
To edit settings, press Ctrl + ,
{{< /example >}}
Sample output
For indicating sample output from a program use the <samp> tag.
{{< example >}} This text is meant to be treated as sample output from a computer program. {{< /example >}}
Tables
Tables are slightly adjusted to style <caption>s, collapse borders, and ensure consistent text-align throughout. Additional changes for borders, padding, and more come with [the .table class]({{< docsref "/content/tables" >}}).
{{< example >}}
| Table heading | Table heading | Table heading | Table heading |
|---|---|---|---|
| Table cell | Table cell | Table cell | Table cell |
| Table cell | Table cell | Table cell | Table cell |
| Table cell | Table cell | Table cell | Table cell |
Forms
Various form elements have been rebooted for simpler base styles. Here are some of the most notable changes:
<fieldset>s have no borders, padding, or margin so they can be easily used as wrappers for individual inputs or groups of inputs.<legend>s, like fieldsets, have also been restyled to be displayed as a heading of sorts.<label>s are set todisplay: inline-blockto allowmarginto be applied.<input>s,<select>s,<textarea>s, and<button>s are mostly addressed by Normalize, but Reboot removes theirmarginand setsline-height: inherit, too.<textarea>s are modified to only be resizable vertically as horizontal resizing often "breaks" page layout.<button>s and<input>button elements havecursor: pointerwhen:not(:disabled).
These changes, and more, are demonstrated below.
Example legend
Choose... Option 1 Option 2 Option 3 Option 4 Option 5 Option 6
Check this checkbox
Option one is this and that Option two is something else that's also super long to demonstrate the wrapping of these fancy form controls. Option three is disabled
100
Button submit
Button submit
{{< callout warning >}} {{< partial "callouts/warning-input-support.md" >}} {{< /callout >}}
Pointers on buttons
Reboot includes an enhancement for role="button" to change the default cursor to pointer. Add this attribute to elements to help indicate elements are interactive. This role isn't necessary for <button> elements, which get their own cursor change.
{{< example >}} Non-button element button {{< /example >}}
Misc elements
Address
The <address> element is updated to reset the browser default font-style from italic to normal. line-height is also now inherited, and margin-bottom: 1rem has been added. <address>s are for presenting contact information for the nearest ancestor (or an entire body of work). Preserve formatting by ending lines with <br>.
1355 Market St, Suite 900
San Francisco, CA 94103
P: (123) 456-7890 Full Name
first.last@example.com
Blockquote
The default margin on blockquotes is 1em 40px, so we reset that to 0 0 1rem for something more consistent with other elements.
A well-known quote, contained in a blockquote element.
Someone famous in Source Title
Inline elements
The <abbr> element receives basic styling to make it stand out amongst paragraph text.
Summary
The default cursor on summary is text, so we reset that to pointer to convey that the element can be interacted with by clicking on it.
Some details
More info about the details.
Even more details
Here are even more details about the details.
HTML5 [hidden] attribute
HTML5 adds a new global attribute named [hidden], which is styled as display: none by default. Borrowing an idea from PureCSS, we improve upon this default by making [hidden] { display: none !important; } to help prevent its display from getting accidentally overridden.
<input type="text" hidden>
{{< callout warning >}}
jQuery incompatibility
[hidden] is not compatible with jQuery's $(...).hide() and $(...).show() methods. Therefore, we don't currently especially endorse [hidden] over other techniques for managing the display of elements.
{{< /callout >}}
To merely toggle the visibility of an element, meaning its display is not modified and the element can still affect the flow of the document, use [the .invisible class]({{< docsref "/utilities/visibility" >}}) instead.