From 3ea39841c8049525e31e9f4d6300f0c60cdb42de Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 24 Jan 2023 13:33:51 +0100 Subject: Adding upstream version 5.2.3+dfsg. Signed-off-by: Daniel Baumann --- site/content/docs/5.2/content/reboot.md | 446 ++++++++++++++++++++++++++++++++ 1 file changed, 446 insertions(+) create mode 100644 site/content/docs/5.2/content/reboot.md (limited to 'site/content/docs/5.2/content/reboot.md') diff --git a/site/content/docs/5.2/content/reboot.md b/site/content/docs/5.2/content/reboot.md new file mode 100644 index 0000000..ca667b2 --- /dev/null +++ b/site/content/docs/5.2/content/reboot.md @@ -0,0 +1,446 @@ +--- +layout: docs +title: Reboot +description: 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. +group: content +aliases: "/docs/5.2/content/" +toc: 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 `` 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 `rem`s instead of `em`s for scalable component spacing. +- Avoid `margin-top`. Vertical margins can collapse, yielding unexpected results. More importantly though, a single direction of `margin` is a simpler mental model. +- For easier scaling across device sizes, block elements should use `rem`s for `margin`s. +- Keep declarations of `font`-related properties to a minimum, using `inherit` whenever possible. + +## CSS variables + +{{< added-in "5.2.0" >}} + +With v5.1.1, we standardized our required `@import`s 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 `` 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: + +```html + + + +``` + +## Page defaults + +The `` and `` elements are updated to provide better page-wide defaults. More specifically: + +- The `box-sizing` is globally set on every element—including `*::before` and `*::after`, to `border-box`. This ensures that the declared width of element is never exceeded due to padding or border. + - No base `font-size` is declared on the ``, but `16px` is assumed (the browser default). `font-size: 1rem` is applied on the `` 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 `$font-size-root` variable. +- The `` also sets a global `font-family`, `font-weight`, `line-height`, and `color`. This is inherited later by some form elements to prevent font inconsistencies. +- For safety, the `` has a declared `background-color`, defaulting to `#fff`. + +## Native font stack + +Bootstrap utilizes a "native font stack" or "system font stack" for optimum text rendering on every device and OS. These system fonts have been designed specifically with today's devices in mind, with improved rendering on screens, variable font support, and more. Read more about [native font stacks in this *Smashing Magazine* article](https://www.smashingmagazine.com/2015/11/using-system-ui-fonts-practical-guide/). + +```scss +$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 `` and automatically inherited globally throughout Bootstrap. To switch the global `font-family`, update `$font-family-base` and recompile Bootstrap. + +## Headings and paragraphs + +All heading elements—e.g., `

`—and `

` are reset to have their `margin-top` removed. Headings have `margin-bottom: .5rem` added and paragraphs `margin-bottom: 1rem` for easy spacing. + +{{< bs-table "table" >}} +| Heading | Example | +| --- | --- | +| `

` | h1. Bootstrap heading | +| `

` | h2. Bootstrap heading | +| `

` | h3. Bootstrap heading | +| `

` | h4. Bootstrap heading | +| `
` | h5. Bootstrap heading | +| `
` | h6. Bootstrap heading | +{{< /bs-table >}} + +## Horizontal rules + +The `
` element has been simplified. Similar to browser defaults, `
`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—`
`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 >}} + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ This is an example table, and this is its caption to describe the contents. +
Table headingTable headingTable headingTable heading
Table cellTable cellTable cellTable cell
Table cellTable cellTable cellTable cell
Table cellTable cellTable cellTable cell
+{{< /example >}} + +## Forms + +Various form elements have been rebooted for simpler base styles. Here are some of the most notable changes: + +- `
`s have no borders, padding, or margin so they can be easily used as wrappers for individual inputs or groups of inputs. +- ``s, like fieldsets, have also been restyled to be displayed as a heading of sorts. +- `
+ + +{{< callout warning >}} +{{< partial "callout-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 `