bootstrap/scss/content/_reboot.scss

@use "../colors" as *;
@use "../config" as *;
@use "../variables" as *;
@use "../vendor/rfs" as *;
@use "../mixins/border-radius" as *;

// stylelint-disable declaration-no-important, selector-no-qualifying-type, property-no-vendor-prefix

@layer reboot {
  // Reboot
  //
  // Normalization of HTML elements, manually forked from Normalize.css to remove
  // styles targeting irrelevant browsers while applying new styles.
  //
  // Normalize is licensed MIT. https://github.com/necolas/normalize.css


  // Document
  //
  // Change from `box-sizing: content-box` so that `width` is not affected by `padding` or `border`.

  *,
  *::before,
  *::after {
    box-sizing: border-box;
  }


  // Root
  //
  // Ability to the value of the root font sizes, affecting the value of `rem`.
  // null by default, thus nothing is generated.

  :root {
    @if $font-size-root != null {
      font-size: var(--#{$prefix}root-font-size);
      // @include font-size(var(--#{$prefix}root-font-size));
    }

    @if $enable-smooth-scroll {
      @media (prefers-reduced-motion: no-preference) {
        scroll-behavior: smooth;
      }
    }
  }


  // Body
  //
  // 1. Remove the margin in all browsers.
  // 2. As a best practice, apply a default `background-color`.
  // 3. Prevent adjustments of font size after orientation changes in iOS.
  // 4. Change the default tap highlight to be completely transparent in iOS.

  // scss-docs-start reboot-body-rules
  body {
    margin: 0; // 1
    font-family: var(--#{$prefix}body-font-family);
    @include font-size(var(--#{$prefix}body-font-size));
    font-weight: var(--#{$prefix}body-font-weight);
    line-height: var(--#{$prefix}body-line-height);
    color: var(--#{$prefix}color-body);
    text-align: var(--#{$prefix}body-text-align);
    background-color: var(--#{$prefix}bg-body); // 2
    -webkit-text-size-adjust: 100%; // 3
    -webkit-tap-highlight-color: rgba($black, 0); // 4
  }
  // scss-docs-end reboot-body-rules


  // Content grouping
  //
  // 1. Reset Firefox's gray color

  hr {
    margin: $hr-margin-y 0;
    color: $hr-color; // 1
    border: 0;
    border-top: $hr-border-width solid $hr-border-color;
    opacity: $hr-opacity;
  }


  // Typography
  //
  // 1. Remove top margins from headings
  //    By default, `<h1>`-`<h6>` all receive top and bottom margins. We nuke the top
  //    margin for easier control within type scales as it avoids margin collapsing.

  %heading {
    margin-top: 0; // 1
    margin-bottom: $headings-margin-bottom;
    font-family: $headings-font-family;
    font-style: $headings-font-style;
    font-weight: $headings-font-weight;
    line-height: $headings-line-height;
    color: var(--#{$prefix}heading-color);
  }

  h1,
  .h1 {
    @extend %heading;
    @include font-size($h1-font-size);
  }

  h2,
  .h2 {
    @extend %heading;
    @include font-size($h2-font-size);
  }

  h3,
  .h3 {
    @extend %heading;
    @include font-size($h3-font-size);
  }

  h4,
  .h4 {
    @extend %heading;
    @include font-size($h4-font-size);
  }

  h5,
  .h5 {
    @extend %heading;
    @include font-size($h5-font-size);
  }

  h6,
  .h6 {
    @extend %heading;
    @include font-size($h6-font-size);
  }


  // Reset margins on paragraphs
  //
  // Similarly, the top margin on `<p>`s get reset. However, we also reset the
  // bottom margin to use `rem` units instead of `em`.

  p {
    margin-top: 0;
    margin-bottom: $paragraph-margin-bottom;
  }


  // Abbreviations
  //
  // 1. Add the correct text decoration in Chrome, Edge, Opera, and Safari.
  // 2. Add explicit cursor to indicate changed behavior.
  // 3. Prevent the text-decoration to be skipped.

  abbr[title] {
    text-decoration: underline dotted; // 1
    cursor: help; // 2
    text-decoration-skip-ink: none; // 3
  }


  // Address

  address {
    margin-bottom: 1rem;
    font-style: normal;
    line-height: inherit;
  }


  // Lists

  ol,
  ul {
    padding-left: 2rem;
  }

  ol,
  ul,
  dl {
    margin-top: 0;
    margin-bottom: 1rem;
  }

  ol ol,
  ul ul,
  ol ul,
  ul ol {
    margin-bottom: 0;
  }

  dt {
    font-weight: $dt-font-weight;
  }

  // 1. Undo browser default

  dd {
    margin-bottom: .5rem;
    margin-left: 0; // 1
  }


  // Blockquote

  blockquote {
    margin: 0 0 1rem;
  }


  // Strong
  //
  // Add the correct font weight in Chrome, Edge, and Safari

  b,
  strong {
    font-weight: $font-weight-bolder;
  }


  // Small
  //
  // Add the correct font size in all browsers

  small,
  .small {
    @include font-size($small-font-size);
  }


  // Mark

  mark,
  .mark {
    padding: $mark-padding;
    color: var(--#{$prefix}highlight-color);
    background-color: var(--#{$prefix}highlight-bg);
  }


  // Sub and Sup
  //
  // Prevent `sub` and `sup` elements from affecting the line height in
  // all browsers.

  sub,
  sup {
    position: relative;
    @include font-size($sub-sup-font-size);
    line-height: 0;
    vertical-align: baseline;
  }

  sub { bottom: -.25em; }
  sup { top: -.5em; }


  // Links

  a {
    color: var(--#{$prefix}link-color);
    text-decoration: var(--#{$prefix}link-decoration);
    text-underline-offset: $link-underline-offset;

    &:hover {
      color: var(--#{$prefix}link-hover-color);
      text-decoration: var(--#{$prefix}link-hover-decoration);
    }
  }

  // And undo these styles for placeholder links/named anchors (without href).
  // It would be more straightforward to just use a[href] in previous block, but that
  // causes specificity issues in many other styles that are too complex to fix.
  // See https://github.com/twbs/bootstrap/issues/19402

  a:not([href]):not([class]) {
    &,
    &:hover {
      color: inherit;
      text-decoration: none;
    }
  }


  // Code

  pre,
  code,
  kbd,
  samp {
    font-family: $font-family-code;
    @include font-size(1em); // Correct the odd `em` font sizing in all browsers.
  }

  // 1. Remove browser default top margin
  // 2. Reset browser default of `1em` to use `rem`s
  // 3. Don't allow content to break outside

  pre {
    display: block;
    margin-top: 0; // 1
    margin-bottom: 1rem; // 2
    overflow: auto; // 3
    @include font-size($code-font-size);
    color: $pre-color;

    // Account for some code outputs that place code tags in pre tags
    code {
      @include font-size(inherit);
      color: inherit;
      word-break: normal;
    }
  }

  code {
    @include font-size($code-font-size);
    color: var(--#{$prefix}code-color);
    word-wrap: break-word;

    // Streamline the style when inside anchors to avoid broken underline and more
    a > & {
      color: inherit;
    }
  }

  kbd {
    padding: $kbd-padding-y $kbd-padding-x;
    @include font-size($kbd-font-size);
    color: $kbd-color;
    background-color: $kbd-bg;
    @include border-radius($border-radius-sm);

    kbd {
      padding: 0;
      @include font-size(1em);
      font-weight: inherit; // mdo-do: check if this is needed
    }
  }


  // Figures
  //
  // Apply a consistent margin strategy (matches our type styles).

  figure {
    margin: 0 0 1rem;
  }


  // Images and content

  img,
  svg {
    vertical-align: middle;
  }


  // Tables
  //
  // Prevent double borders

  table {
    caption-side: bottom;
    border-collapse: collapse;
  }

  caption {
    // padding-top: $table-cell-padding-y;
    // padding-bottom: $table-cell-padding-y;
    // color: $table-caption-color;
    padding-block: .5rem;
    color: var(--#{$prefix}secondary-color);
    text-align: left;
  }

  // 1. Removes font-weight bold by inheriting
  // 2. Matches default `<td>` alignment by inheriting `text-align`.
  // 3. Fix alignment for Safari

  th {
    // font-weight: $table-th-font-weight; // 1 // mdo-do: it's null by default. maybe we remove?
    text-align: inherit; // 2
    text-align: -webkit-match-parent; // 3
  }

  thead,
  tbody,
  tfoot,
  tr,
  td,
  th {
    border-color: inherit;
    border-style: solid;
    border-width: 0;
  }


  // Forms
  //
  // 1. Allow labels to use `margin` for spacing.

  label {
    display: inline-block; // 1
  }

  // Remove the default `border-radius` that macOS Chrome adds.
  // See https://github.com/twbs/bootstrap/issues/24093

  button {
    // stylelint-disable-next-line property-disallowed-list
    border-radius: 0;
  }

  // Explicitly remove focus outline in Chromium when it shouldn't be
  // visible (e.g. as result of mouse click or touch tap). It already
  // should be doing this automatically, but seems to currently be
  // confused and applies its very visible two-tone outline anyway.

  button:focus:not(:focus-visible) {
    outline: 0;
  }

  // 1. Remove the margin in Firefox and Safari

  input,
  button,
  select,
  optgroup,
  textarea {
    margin: 0; // 1
    font-family: inherit;
    @include font-size(inherit);
    line-height: inherit;
  }

  // Remove the inheritance of text transform in Firefox
  button,
  select {
    text-transform: none;
  }
  // Set the cursor for non-`<button>` buttons
  //
  // Details at https://github.com/twbs/bootstrap/pull/30562
  [role="button"] {
    cursor: pointer;
  }

  select {
    // Remove the inheritance of word-wrap in Safari.
    // See https://github.com/twbs/bootstrap/issues/24990
    word-wrap: normal;

    // Undo the opacity change from Chrome
    &:disabled {
      opacity: 1;
    }
  }

  // Remove the dropdown arrow only from text type inputs built with datalists in Chrome.
  // See https://stackoverflow.com/a/54997118

  [list]:not([type="date"]):not([type="datetime-local"]):not([type="month"]):not([type="week"]):not([type="time"])::-webkit-calendar-picker-indicator {
    display: none !important;
  }

  // 1. Prevent a WebKit bug where (2) destroys native `audio` and `video`
  //    controls in Android 4.
  // 2. Correct the inability to style clickable types in iOS and Safari.
  // 3. Opinionated: add "hand" cursor to non-disabled button elements.

  button,
  [type="button"], // 1
  [type="reset"],
  [type="submit"] {
    -webkit-appearance: button; // 2

    @if $enable-button-pointers {
      &:not(:disabled) {
        cursor: pointer; // 3
      }
    }
  }

  // Remove inner border and padding from Firefox, but don't restore the outline like Normalize.

  ::-moz-focus-inner {
    padding: 0;
    border-style: none;
  }

  // 1. Textareas should really only resize vertically so they don't break their (horizontal) containers.

  textarea {
    resize: vertical; // 1
  }

  // 1. Browsers set a default `min-width: min-content;` on fieldsets,
  //    unlike e.g. `<div>`s, which have `min-width: 0;` by default.
  //    So we reset that to ensure fieldsets behave more like a standard block element.
  //    See https://github.com/twbs/bootstrap/issues/12359
  //    and https://html.spec.whatwg.org/multipage/#the-fieldset-and-legend-elements
  // 2. Reset the default outline behavior of fieldsets so they don't affect page layout.

  fieldset {
    min-width: 0; // 1
    padding: 0; // 2
    margin: 0; // 2
    border: 0; // 2
  }

  // 1. By using `float: left`, the legend will behave like a block element.
  //    This way the border of a fieldset wraps around the legend if present.
  // 2. Fix wrapping bug.
  //    See https://github.com/twbs/bootstrap/issues/29712

  legend {
    float: left; // 1
    width: 100%;
    padding: 0;
    margin-bottom: $legend-margin-bottom;
    font-weight: $legend-font-weight;
    line-height: inherit;
    @include font-size($legend-font-size);

    + * {
      clear: left; // 2
    }
  }

  // Fix height of inputs with a type of datetime-local, date, month, week, or time
  // See https://github.com/twbs/bootstrap/issues/18842

  ::-webkit-datetime-edit-fields-wrapper,
  ::-webkit-datetime-edit-text,
  ::-webkit-datetime-edit-minute,
  ::-webkit-datetime-edit-hour-field,
  ::-webkit-datetime-edit-day-field,
  ::-webkit-datetime-edit-month-field,
  ::-webkit-datetime-edit-year-field {
    padding: 0;
  }

  ::-webkit-inner-spin-button {
    height: auto;
  }

  // 1. This overrides the extra rounded corners on search inputs in iOS so that our
  //    `.form-control` class can properly style them. Note that this cannot simply
  //    be added to `.form-control` as it's not specific enough. For details, see
  //    https://github.com/twbs/bootstrap/issues/11586.
  // 2. Correct the outline style in Safari.

  [type="search"] {
    -webkit-appearance: textfield; // 1
    outline-offset: -2px; // 2

    // 3. Better affordance and consistent appearance for search cancel button
    &::-webkit-search-cancel-button {
      cursor: pointer;
      filter: grayscale(1);
    }
  }

  // 1. A few input types should stay LTR
  // See https://rtlstyling.com/posts/rtl-styling#form-inputs
  // 2. RTL only output
  // See https://rtlcss.com/learn/usage-guide/control-directives/#raw

  /* rtl:raw:
  [type="tel"],
  [type="url"],
  [type="email"],
  [type="number"] {
    direction: ltr;
  }
  */

  // Remove the inner padding in Chrome and Safari on macOS.

  ::-webkit-search-decoration {
    -webkit-appearance: none;
  }

  // Remove padding around color pickers in webkit browsers

  ::-webkit-color-swatch-wrapper {
    padding: 0;
  }


  // 1. Inherit font family and line height for file input buttons
  // 2. Correct the inability to style clickable types in iOS and Safari.

  ::file-selector-button {
    font: inherit; // 1
    -webkit-appearance: button; // 2
  }

  // Correct element displays

  output {
    display: inline-block;
  }

  // Remove border from iframe

  iframe {
    border: 0;
  }

  // Summary
  //
  // 1. Add the correct display in all browsers

  summary {
    display: list-item; // 1
    cursor: pointer;
  }


  // Progress
  //
  // Add the correct vertical alignment in Chrome, Firefox, and Opera.

  progress {
    vertical-align: baseline;
  }


  // Hidden attribute
  //
  // Always hide an element with the `hidden` HTML attribute.

  [hidden] {
    display: none !important;
  }
}