toggle_button.css

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

.toggle-button {
  --button-background-color: #f0f0f4;
  --button-background-color-hover: #e0e0e6;
  --button-background-color-active: #cfcfd8;
  --color-accent-primary: #0060df;
  --color-accent-primary-hover: #0250bb;
  --color-accent-primary-active: #054096;
  --border-interactive-color: #8f8f9d;
  --border-radius-circle: 9999px;
  --border-width: 1px;
  --size-item-small: 16px;
  --size-item-large: 32px;
  --color-canvas: white;

  @media (prefers-color-scheme: dark) {
    --button-background-color: color-mix(in srgb, currentColor 7%, transparent);
    --button-background-color-hover: color-mix(
      in srgb,
      currentColor 14%,
      transparent
    );
    --button-background-color-active: color-mix(
      in srgb,
      currentColor 21%,
      transparent
    );
    --color-accent-primary: #0df;
    --color-accent-primary-hover: #80ebff;
    --color-accent-primary-active: #aaf2ff;
    --border-interactive-color: #bfbfc9;
    --color-canvas: #1c1b22;
  }

  @media (forced-colors: active) {
    --color-accent-primary: ButtonText;
    --color-accent-primary-hover: SelectedItem;
    --color-accent-primary-active: SelectedItem;
    --border-interactive-color: ButtonText;
    --button-background-color: ButtonFace;
    --border-interactive-color-hover: SelectedItem;
    --border-interactive-color-active: SelectedItem;
    --border-interactive-color-disabled: GrayText;
    --color-canvas: ButtonText;
  }

  /* 
    The original file is located at:
    https://hg.mozilla.org/mozilla-central/file/aded201f11ec90b8e11c59d1e399960785771fbd/toolkit/content/widgets/moz-toggle/moz-toggle.css

    The original file is licensed under the Mozilla Public License, v. 2.0.
    This file is a modified version of the original file.

    In order to have a better reading of the code, the .toggle-button selector
    has been removed from the original file and we put everything under a single
    .toggle-button selector.
    
    TODO: check from times to times if the original file has been updated (and 
    in such a case don't forget to change the revision in the above link).
  */

  --toggle-background-color: var(--button-background-color);
  --toggle-background-color-hover: var(--button-background-color-hover);
  --toggle-background-color-active: var(--button-background-color-active);
  --toggle-background-color-pressed: var(--color-accent-primary);
  --toggle-background-color-pressed-hover: var(--color-accent-primary-hover);
  --toggle-background-color-pressed-active: var(--color-accent-primary-active);
  --toggle-border-color: var(--border-interactive-color);
  --toggle-border-color-hover: var(--toggle-border-color);
  --toggle-border-color-active: var(--toggle-border-color);
  --toggle-border-radius: var(--border-radius-circle);
  --toggle-border-width: var(--border-width);
  --toggle-height: var(--size-item-small);
  --toggle-width: var(--size-item-large);
  --toggle-dot-background-color: var(--toggle-border-color);
  --toggle-dot-background-color-hover: var(--toggle-dot-background-color);
  --toggle-dot-background-color-active: var(--toggle-dot-background-color);
  --toggle-dot-background-color-on-pressed: var(--color-canvas);
  --toggle-dot-margin: 1px;
  --toggle-dot-height: calc(
    var(--toggle-height) - 2 * var(--toggle-dot-margin) - 2 *
      var(--toggle-border-width)
  );
  --toggle-dot-width: var(--toggle-dot-height);
  --toggle-dot-transform-x: calc(
    var(--toggle-width) - 4 * var(--toggle-dot-margin) - var(--toggle-dot-width)
  );

  appearance: none;
  padding: 0;
  margin: 0;
  border: var(--toggle-border-width) solid var(--toggle-border-color);
  height: var(--toggle-height);
  width: var(--toggle-width);
  border-radius: var(--toggle-border-radius);
  background: var(--toggle-background-color);
  box-sizing: border-box;
  flex-shrink: 0;

  &:focus-visible {
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
  }

  &:enabled:hover {
    background: var(--toggle-background-color-hover);
    border-color: var(--toggle-border-color);
  }

  &:enabled:active {
    background: var(--toggle-background-color-active);
    border-color: var(--toggle-border-color);
  }

  &[aria-pressed="true"] {
    background: var(--toggle-background-color-pressed);
    border-color: transparent;
  }

  &[aria-pressed="true"]:enabled:hover {
    background: var(--toggle-background-color-pressed-hover);
    border-color: transparent;
  }

  &[aria-pressed="true"]:enabled:active {
    background: var(--toggle-background-color-pressed-active);
    border-color: transparent;
  }

  &::before {
    display: block;
    content: "";
    background-color: var(--toggle-dot-background-color);
    height: var(--toggle-dot-height);
    width: var(--toggle-dot-width);
    margin: var(--toggle-dot-margin);
    border-radius: var(--toggle-border-radius);
    translate: 0;
  }

  &[aria-pressed="true"]::before {
    translate: var(--toggle-dot-transform-x);
    background-color: var(--toggle-dot-background-color-on-pressed);
  }

  &[aria-pressed="true"]:enabled:hover::before,
  &[aria-pressed="true"]:enabled:active::before {
    background-color: var(--toggle-dot-background-color-on-pressed);
  }

  /*#if MOZCENTRAL*/
  /*&[aria-pressed="true"]:-moz-locale-dir(rtl)::before,*/
  /*#endif*/
  &[aria-pressed="true"]:dir(rtl)::before {
    translate: calc(-1 * var(--toggle-dot-transform-x));
  }

  @media (prefers-reduced-motion: no-preference) {
    &::before {
      transition: translate 100ms;
    }
  }

  @media (prefers-contrast) {
    &:enabled:hover {
      border-color: var(--toggle-border-color-hover);
    }

    &:enabled:active {
      border-color: var(--toggle-border-color-active);
    }

    &[aria-pressed="true"]:enabled {
      border-color: var(--toggle-border-color);
      position: relative;
    }

    &[aria-pressed="true"]:enabled:hover,
    &[aria-pressed="true"]:enabled:hover:active {
      border-color: var(--toggle-border-color-hover);
    }

    &[aria-pressed="true"]:enabled:active {
      background-color: var(--toggle-dot-background-color-active);
      border-color: var(--toggle-dot-background-color-hover);
    }

    &:hover::before,
    &:active::before {
      background-color: var(--toggle-dot-background-color-hover);
    }
  }

  @media (forced-colors) {
    --toggle-dot-background-color: var(--color-accent-primary);
    --toggle-dot-background-color-hover: var(--color-accent-primary-hover);
    --toggle-dot-background-color-active: var(--color-accent-primary-active);
    --toggle-dot-background-color-on-pressed: var(--button-background-color);
    --toggle-background-color-disabled: var(--button-background-color-disabled);
    --toggle-border-color-hover: var(--border-interactive-color-hover);
    --toggle-border-color-active: var(--border-interactive-color-active);
    --toggle-border-color-disabled: var(--border-interactive-color-disabled);

    &[aria-pressed="true"]:enabled::after {
      border: 1px solid var(--button-background-color);
      content: "";
      position: absolute;
      height: var(--toggle-height);
      width: var(--toggle-width);
      display: block;
      border-radius: var(--toggle-border-radius);
      inset: -2px;
    }

    &[aria-pressed="true"]:enabled:active::after {
      border-color: var(--toggle-border-color-active);
    }
  }
}