docs/common/header.css

/*
 * Copyright 2026 The Pigweed Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

/* ========== THEME & FONT VARIABLES ========== */
:root {
  /* Pigweed typography variables */
  --pw-font-body: 'Noto Sans', sans-serif;
  --pw-font-code: 'Roboto Mono', monospace;
  --pw-font-headings: 'Lato', sans-serif;

  /* Header and breadcrumbs layout variables */
  --pw-header-height: 56px;
  --pw-breadcrumbs-height: 30px;
  --pw-header-padding-x: 24px;
}

@media (max-width: 839px) {
  :root {
    --pw-header-height: 52px;
    --pw-breadcrumbs-height: 28px;
    --pw-header-padding-x: 1rem;
  }
}

body {
  margin: 0;
  padding-top: var(--pw-header-height) !important;
  box-sizing: border-box;
  min-height: 100vh;
}

/* Universal Skip Link for keyboard and screen reader accessibility */
.pw-skip-link {
  position: fixed;
  top: -100px;
  left: var(--pw-header-padding-x);
  z-index: 10001;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 16px;
  box-sizing: border-box;
  background-color: var(--pw-color-background-primary);
  color: var(--pw-color-foreground-primary) !important;
  border: 1px solid var(--pf-border);
  border-radius: 6px;
  font-family: var(--pw-font-body);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none !important;
  box-shadow: var(--pf-shadow-md);
  transition:
    top 0.15s ease-in-out,
    background-color 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease;
}

.pw-skip-link:hover {
  background-color: var(--pf-hover);
  color: var(--pw-color-link) !important;
  border-color: var(--pf-border-focus);
}

.pw-skip-link:focus,
.pw-skip-link:focus-visible {
  top: calc((var(--pw-header-height) - 36px) / 2);
  outline: 2px solid var(--pf-outline-focus);
  outline-offset: 2px;
  border-color: var(--pf-border-focus);
}

/* ========== TOP HEADER BAR LAYOUT ========== */
#pw-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: var(--pw-header-height);
  box-sizing: border-box;
  z-index: 1000;
  display: flex;
  align-items: center;
  /* Use flex-start instead of space-between so that on mobile #pw-header-menu
   * and #pw-header-brand remain grouped on the left, while #pw-header-tools is
   * pushed to the far right via margin-left: auto. */
  justify-content: flex-start;
  background-color: var(--pw-color-background-secondary);
  color: var(--pw-color-foreground-primary);
  padding: 0 var(--pw-header-padding-x);
  border-bottom: 1px solid var(--pf-border);
  font-family: var(--pw-font-body);
}

/* Brand container: menu toggle button, logo, and site title. */
#pw-header-menu {
  display: flex !important;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  color: var(--pw-color-foreground-primary);
  cursor: pointer;
  padding: 4px;
  margin: 0 12px 0 0;
  border-radius: 4px;
  line-height: 1;

  &:hover {
    background-color: var(--pf-hover);
  }

  &:focus-visible {
    outline: 2px solid var(--pf-outline-focus);
  }

  .material-symbols-outlined {
    font-size: 24px;
    line-height: 1;
    display: block;
    user-select: none;
  }
}

@media (min-width: 840px) {
  #pw-header-menu {
    display: none !important;
  }
}

#pw-header-brand {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
  margin-right: 0;

  @media (min-width: 840px) {
    margin-right: 0;
  }

  a,
  a:visited,
  a:hover,
  a:active {
    color: var(--pw-color-foreground-primary);
    font-family: var(--pw-font-headings);
    font-weight: bold;
    font-style: italic;
    font-size: 22px;
    margin: 0 !important;
    padding: 0;
    white-space: nowrap;
    text-decoration: none;
  }

  img {
    height: 30px;
    width: auto;
  }

  @media (max-width: 839px) {
    img {
      height: 26px;
    }

    a,
    a:visited,
    a:hover,
    a:active {
      font-size: 20px;
    }
  }
}

/* Site navigation links and dropdown popovers. */
#pw-header-nav {
  display: none !important;
}

@media (min-width: 840px) {
  #pw-header-nav {
    display: flex !important;
    align-items: center;
    height: 100%;
    gap: 2px;
    margin-left: auto !important;
    margin-right: 12px;
    overflow: visible;
  }
}

.pw-nav-item {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.pw-nav-link,
.pw-nav-link:visited {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  height: 36px;
  padding: 0 8px;
  color: var(--pw-color-foreground-primary) !important;
  text-decoration: none !important;
  font-size: 13px;
  font-weight: 500;
  border-radius: 6px;
  white-space: nowrap;
  transition:
    background-color 0.15s ease,
    color 0.15s ease;

  &:hover,
  &:active {
    background-color: var(--pf-hover);
    color: var(--pw-color-link) !important;
    text-decoration: none !important;
  }
}

.pw-nav-item:hover > .pw-nav-link,
.pw-nav-item:focus-within > .pw-nav-link {
  background-color: var(--pf-hover);
  color: var(--pw-color-link) !important;
  text-decoration: none !important;
}

.pw-dropdown-arrow {
  display: inline-block;
  font-size: 18px;
  line-height: 1;
  text-decoration: none !important;
  user-select: none;
}

.pw-nav-item:hover .pw-dropdown-arrow,
.pw-nav-item:focus-within .pw-dropdown-arrow {
  transform: rotate(180deg);
}

/* Dropdown popover container */
.pw-nav-popover {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  max-width: 320px;
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  background-color: var(--pw-color-background-primary);
  border: 1px solid var(--pf-border);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  padding: 6px 0;
  margin: 0;
  z-index: 1001;
}

.pw-nav-item:hover > .pw-nav-popover,
.pw-nav-item:focus-within > .pw-nav-popover {
  display: block !important;
}

.pw-nav-item.is-closed > .pw-nav-popover {
  display: none !important;
}

.pw-nav-item.is-closed .pw-dropdown-arrow {
  transform: none !important;
}

.pw-nav-item:nth-last-child(-n + 4) > .pw-nav-popover {
  left: auto;
  right: 0;
}

.pw-nav-dropdown-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.pw-nav-dropdown-link,
.pw-nav-dropdown-link:visited {
  display: block;
  padding: 8px 16px;
  color: var(--pw-color-foreground-primary) !important;
  text-decoration: none;
  font-size: 14px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition:
    background-color 0.15s ease,
    color 0.15s ease;

  &:hover,
  &:focus,
  &:active {
    background-color: var(--pf-hover);
    color: var(--pw-color-link) !important;
  }
}

/* Search UI elements within the header bar (desktop trigger and mobile button).
 * Styles for the Pagefind search modal and search results outside the header
 * live in search.css. */
#pw-header-search {
  display: none !important;
  height: 100%;
}

#pw-search-mobile {
  background-color: var(--pw-color-background-primary);
  border: 1px solid var(--pf-border);
  color: var(--pw-color-foreground-primary);
  cursor: pointer;
  padding: 0;
  margin: 0;
  display: flex !important;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  box-sizing: border-box;
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease;

  &:hover {
    background-color: var(--pf-hover);
  }

  &:focus-visible {
    outline: 2px solid var(--pf-outline-focus);
  }

  .material-symbols-outlined {
    font-size: 20px;
    line-height: 1;
    display: block;
    user-select: none;
  }
}

pagefind-modal-trigger {
  all: unset !important;
  display: inline-flex !important;
  align-items: center !important;
  contain: none !important;
  flex-shrink: 0 !important;
}

pagefind-modal-trigger .pf-trigger-btn {
  display: inline-flex !important;
  align-items: center !important;
  height: 36px !important;
  background: var(--pf-background) !important;
  border: 1px solid var(--pf-border) !important;
  border-radius: var(--pf-border-radius) !important;
  color: var(--pw-color-foreground-primary) !important;
  cursor: pointer !important;
  box-sizing: border-box !important;
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease;

  &:hover {
    background-color: var(--pf-hover) !important;
    border-color: var(--pf-border-focus) !important;
  }

  &:focus-visible {
    outline: 2px solid var(--pf-outline-focus) !important;
  }
}

pagefind-modal-trigger .pf-trigger-icon {
  width: 16px !important;
  height: 16px !important;
  display: inline-block !important;
  background-color: var(--pw-color-foreground-primary) !important;
  -webkit-mask-image: var(--pf-icon-search) !important;
  mask-image: var(--pf-icon-search) !important;
  -webkit-mask-size: 100% 100% !important;
  mask-size: 100% 100% !important;
  -webkit-mask-repeat: no-repeat !important;
  mask-repeat: no-repeat !important;
  -webkit-mask-position: center !important;
  mask-position: center !important;
  flex-shrink: 0 !important;
}

/* Wide viewports (1120px and higher):
 * Display full desktop search bar in header flow and hide condensed button.
 * Between 840px and 1120px, the navigation links stay visible while search
 * switches to the condensed button in #pw-header-tools to prevent overflow. */
@media (min-width: 1120px) {
  #pw-header-search {
    display: flex !important;
    align-items: center;
    flex-shrink: 0;
    margin-left: 0;
    margin-right: 8px;
  }

  pagefind-modal-trigger {
    width: 260px !important;
  }

  pagefind-modal-trigger .pf-trigger-btn {
    width: 100% !important;
    padding: 0 14px !important;
    gap: 8px !important;
  }

  #pw-search-mobile {
    display: none !important;
  }
}

/* Tools container: action buttons such as search and the theme selector.
 * On mobile (<840px), margin-left: auto pushes tools to the far right edge,
 * ensuring the largest gap is in the middle between the brand and tools.
 * On desktop (>=840px), nav already has margin-left: auto, so tools margin-left is 0. */
#pw-header-tools {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
  margin-left: auto;

  @media (min-width: 840px) {
    margin-left: 0;
  }
}

/* Theme switcher component within the header bar. Root-level theme CSS
 * variables that transcend the header live in theme.css. */
pw-theme {
  display: inline-flex !important;
  align-items: center !important;
  flex-shrink: 0 !important;
  background-color: var(--pw-color-background-primary);
  border: 1px solid var(--pf-border);
  border-radius: 20px;
  padding: 2px;
  gap: 2px;
  box-sizing: border-box;
}

.pw-theme-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  padding: 0;
  border: none;
  background: transparent;
  color: var(--pf-text-muted);
  border-radius: 50%;
  cursor: pointer;
  transition:
    background-color 0.15s ease,
    color 0.15s ease;
  line-height: 1;

  .material-symbols-outlined {
    font-size: 20px;
    display: block;
    line-height: 1;
    user-select: none;
  }

  &:hover {
    color: var(--pw-color-foreground-primary);
    background-color: var(--pf-hover);
  }

  &:focus-visible {
    outline: 2px solid var(--pf-outline-focus);
  }

  &.active {
    background-color: var(--pw-color-background-code);
    color: var(--pw-color-link);
  }
}

/* ========== NATIVE HEADER REPLACEMENTS ========== */
/* Hide native headers from Sphinx and Doxygen that are superseded by the
 * universal header bar. */
#pst-header,
#navrow1 {
  display: none !important;
}

/* Suppress native Sphinx and Rustdoc skip links in favor of the universal
 * pw-skip-link component. */
#pst-skip-link,
.skip-main-content {
  display: none !important;
}

/* Hide the 'ayu' theme option in Rustdoc settings. */
label[for='theme-ayu'] {
  display: none !important;
}

/* Prevent #main-content from inheriting Rustdoc's yellow :target highlight
 * when targeted by the skip link. */
#main-content:target {
  background-color: transparent !important;
  border-right: none !important;
}