Reboot

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 pxs instead of ems for fixed component spacing, to keep as much space as possible for meaningful content on zoom.
• 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 pxs for margins.
• Keep declarations of font-related properties to a minimum, using inherit whenever possible. We use max-width on all font references for readability reasons. If you want to get rid of the max-width, please make sure to use our .mw-none width utility.

CSS variables

OUDS Web standards require @imports across all our CSS bundles (including ouds-web.css, ouds-web-reboot.css, and ouds-web-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 OUDS Web will continue to see more 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 :root styles:

@if $font-size-root != null {
  --#{$prefix}root-font-size: #{$font-size-root};
}
--#{$prefix}body-font-family: #{inspect($font-family-base)};
@include rfs($font-size-base, --#{$prefix}body-font-size);
--#{$prefix}body-font-weight: #{$font-weight-base};
--#{$prefix}body-line-height: #{$line-height-base};
--#{$prefix}body-letter-spacing: #{$letter-spacing-base}; // OUDS mod
@if $body-text-align != null {
  --#{$prefix}body-text-align: #{$body-text-align};
}

@if $enable-bootstrap-compatibility {
  --#{$prefix}body-color: #{$body-color};
  --#{$prefix}body-color-rgb: #{to-rgb($body-color)};
  --#{$prefix}body-bg: #{$body-bg};
  --#{$prefix}body-bg-rgb: #{to-rgb($body-bg)};

  --#{$prefix}emphasis-color: #{$body-emphasis-color};
  --#{$prefix}emphasis-color-rgb: #{to-rgb($body-emphasis-color)};

  --#{$prefix}secondary-color: #{$body-secondary-color};
  --#{$prefix}secondary-color-rgb: #{to-rgb($body-secondary-color)};
  --#{$prefix}secondary-bg: #{$body-secondary-bg};
  --#{$prefix}secondary-bg-rgb: #{to-rgb($body-secondary-bg)};

  --#{$prefix}tertiary-color: #{$body-tertiary-color};
  --#{$prefix}tertiary-color-rgb: #{to-rgb($body-tertiary-color)};
  --#{$prefix}tertiary-bg: #{$body-tertiary-bg};
  --#{$prefix}tertiary-bg-rgb: #{to-rgb($body-tertiary-bg)};
}

In practice, those variables are then applied in Reboot like so:

#{$ouds-root-selector} > * { // OUDS mod: instead of `body`
  position: relative; // OUDS mod: required for back-to-top component
  margin: 0; // 1
  font-family: var(--#{$prefix}body-font-family);
  font-synthesis: none; // OUDS mod // 5
  @include font-size(var(--#{$prefix}body-font-size));
  font-weight: var(--#{$prefix}body-font-weight);
  line-height: var(--#{$prefix}body-line-height);
  color: var(--#{$prefix}color-content-default); // OUDS mod: instead of `var(--#{$prefix}body-color)`
  text-align: var(--#{$prefix}body-text-align);

  /* rtl:remove */
  letter-spacing: var(--#{$prefix}body-letter-spacing); // OUDS mod
  background-color: var(--#{$prefix}color-bg-primary); // 2 // OUDS mod: instead of `var(--#{$prefix}body-bg)`
  -webkit-text-size-adjust: 100%; // 3
  -webkit-tap-highlight-color: rgba($black, 0); // 4
  -webkit-font-smoothing: subpixel-antialiased; // OUDS mod
  text-rendering: optimizespeed; // OUDS mod
}

Which allows you to make real-time customizations however you like:

<body style="--bs-body-color: #333;">
  <!-- ... -->
</body>

Page defaults

The :root and child 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 <html>, but 16px is assumed (the browser default). font-size: 1rem is applied on the :root children 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 :root children 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 :root children has a declared background-color, defaulting to #fff.

Native font stack

OUDS Web 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:
  // Safari for macOS and iOS (San Francisco)
  "SF Pro",
  // Android
  Roboto,
  // older macOS and iOS
  "Helvetica Neue",
  // Windows
  Helvetica
  // Basic web fallback
  Arial,
  // Sans serif fallback
  sans-serif !default;

This font-family is applied to the <body> and automatically inherited globally throughout OUDS Web. To switch the global font-family, update $font-family-base and recompile OUDS Web.

The following font-family is applied on every code basis element. To switch the global font-family, update $font-family-code and recompile OUDS Web.

$font-family-sans-serif:
  // Safari for macOS and iOS (San Francisco)
  "SF Mono",
  // Android
  "Roboto Mono",
  // Windows
  Consolas,
  // Basic web fallback
  Menlo,
  // Monospace fallback
  monospace !default;

Headings

All heading elements—<h1>—<h6> have their margin-top removed, margin-bottom: 16px set, and line-height tightened. While headings inherit their color by default, you can also override it via optional CSS variable, --bs-heading-color.

Paragraphs

All <p> elements have their margin-top removed and margin-bottom: 16px set for easy spacing. If you want to get rid of the margin-bottom, please make sure to use our .mb-none spacing utilities.

<p class="mw-none mb-none">This is an example paragraph which is long enough so it's easy to see and compare the <code>max-width</code> in action and compare it to the one below.</p>
<p>This is an example paragraph which is long enough so it's easy to see and compare the <code>max-width</code> in action and compare it to the one above.</p>
<p>This is an example paragraph.</p>

Links

Links have bold and underline applied. While links change on :hover, by default they don’t change based on whether someone :visited the link.

<a href="#">This is an example link</a>

Links have a disabled style when using an aria-disabled="true" attribute.

<a aria-disabled="true">This is an example of a disabled link</a>

Visited links don’t have a specific style by default. The :visited state can be styled with the additional .visited-links utility class that can be applied directly to a link or to a parent element to style all the child links.

<div class="visited-links">
  <div>
    <a href=".">This is an example of a visited link</a>
  </div>
  <div>
    <a href="#">This is an example of an unvisited link</a>
  </div>
</div>
<div>
  <a href="." class="visited-links">This is an example of a visited link</a>
</div>

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.

<a>This is a placeholder link</a>

On colored backgrounds, links should have a different style. Visited links don’t have a specific style on colored backgrounds.

<div class="colored-bg">
  <div class="bg-brand-primary p-tall">
    <div data-bs-theme="light">
      This is an example of a <a href="#">link on colored background</a> in a paragraph.
    </div>
  </div>
  <div class="bg-status-negative-emphasized p-tall">
    <div data-bs-theme="root-inverted">
      This is an example of <a href="#">link on colored background</a> in a paragraph.
    </div>
  </div>
</div>
<div class="bg-brand-primary p-tall">
  <div data-bs-theme="light">
    This is an example of a <a href="." class="colored-bg visited-links">link on colored background</a> in a paragraph.
  </div>
</div>

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.

<hr>

<div class="text-status-positive">
  <hr>
</div>

<hr class="border border-emphasized border-medium opacity-medium">
<hr class="border border-brand-primary border-thick opacity-strong">

Inline code

Wrap inline snippets of code with <code>. Be sure to escape HTML angle brackets.

For example, <code>&lt;section&gt;</code> should be wrapped as inline.

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 px units for its margin-bottom.

<p>Sample text here...</p>
<p>And another line of sample text here...</p>

<pre><code>&lt;p&gt;Sample text here...&lt;/p&gt;
&lt;p&gt;And another line of sample text here...&lt;/p&gt;
</code></pre>

Variables

For indicating variables use the <var> tag.

<var>y</var> = <var>m</var><var>x</var> + <var>b</var>

User input

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

To switch directories, type <kbd>cd</kbd> followed by the name of the directory.<br>
To edit settings, press <kbd><kbd>Ctrl</kbd> + <kbd>,</kbd></kbd>

Sample output

For indicating sample output from a program use the <samp> tag.

<samp>This text is meant to be treated as sample output from a computer program.</samp>

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.

<table>
  <caption>
    This is an example table, and this is its caption to describe the contents.
  </caption>
  <thead>
    <tr>
      <th>Table heading</th>
      <th>Table heading</th>
      <th>Table heading</th>
      <th>Table heading</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Table cell</td>
      <td>Table cell</td>
      <td>Table cell</td>
      <td>Table cell</td>
    </tr>
    <tr>
      <td>Table cell</td>
      <td>Table cell</td>
      <td>Table cell</td>
      <td>Table cell</td>
    </tr>
    <tr>
      <td>Table cell</td>
      <td>Table cell</td>
      <td>Table cell</td>
      <td>Table cell</td>
    </tr>
  </tbody>
</table>

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 to display: inline-block to allow margin to be applied.
• <input>s, <select>s, <textarea>s, and <button>s are mostly addressed by Normalize, but Reboot removes their margin and sets line-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 have cursor: pointer when :not(:disabled).

These changes, and more, are demonstrated below.

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.

<span role="button" tabindex="0">Non-button element button</span>

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: 16px 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>.

Blockquote

The default margin on blockquotes is 1em 40px, so we reset that to 0 0 16px for something more consistent with other elements.

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.

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>

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 instead.