/* ========================================
   Site shell: header, layout grid, theme toggle, pickers, search box, footer
   (split from main.css, PLAN-165 D9)
   ======================================== */

/* Site Header (PLAN-287 D5): white with a hairline on doc pages, inside
   the indigo band on the home page (.site-header--band).
   ---------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-header-bg);
  color: var(--color-on-header);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-header);
  /* Fixed height: the sticky offsets of the sidebar and the detail rail
     are calc()'d from --header-height. */
  height: var(--header-height);
  padding: 0 var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-5);
}

.site-header--band {
  background-color: var(--color-band);
  color: var(--color-on-band);
  border-bottom-color: rgb(255 255 255 / 0.12);
}

/* Mobile menu toggle (hamburger) — hidden on wide viewports */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 40px;
  height: 40px;
  padding: var(--space-2);
  border: none;
  border-radius: var(--radius-md);
  background: none;
  cursor: pointer;
  flex-shrink: 0;
}

.menu-toggle-bar {
  display: block;
  height: 2px;
  width: 100%;
  background-color: currentColor;
  border-radius: 1px;
}

.menu-toggle:hover {
  background-color: var(--color-header-search-bg-hover);
}

.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgb(0 0 0 / 0.4);
  z-index: 150;
}

.sidebar-backdrop[hidden] {
  display: none;
}

.header-logo {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  color: var(--color-primary);
}

.header-logo:hover {
  text-decoration: none;
}

.header-wordmark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  white-space: nowrap;
}

.site-header--band .header-logo {
  color: var(--color-on-band);
}

/* The tabs (PLAN-287 D12): the current one is underlined. */
.header-tabs {
  align-self: stretch;
  display: flex;
}

.tabs-list {
  display: flex;
  gap: var(--space-5);
  margin: 0;
  padding: 0;
  list-style: none;
}

.header-tab {
  display: flex;
  align-items: center;
  height: 100%;
  font-size: 13.5px;
  color: var(--color-on-header-muted);
  white-space: nowrap;
}

.header-tab:hover {
  color: var(--color-on-header);
  text-decoration: none;
}

.header-tab.is-active {
  color: var(--color-on-header);
  font-weight: 500;
  box-shadow: inset 0 -2px 0 var(--color-primary);
}

.site-header--band .header-tab {
  color: var(--color-on-band-muted);
}

.site-header--band .header-tab:hover,
.site-header--band .header-tab.is-active {
  color: var(--color-on-band);
}

.site-header--band .header-tab.is-active {
  box-shadow: inset 0 -2px 0 var(--color-on-band);
}

/* The drawer's copy of the tabs shows only on narrow screens. */
.drawer-tabs {
  display: none;
}

/* The search box sits at the right of the bar, before the controls. */
.header-search {
  position: relative;
  flex: 0 1 16rem;
  min-width: 0;
  margin-left: auto;
  display: flex;
  align-items: center;
}

.header-search .search-container {
  flex: 1;
  max-width: none;
  min-width: 0;
}

/* ⌘K / Ctrl K inside the box, gone while typing. */
.search-kbd {
  position: absolute;
  right: var(--space-2);
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.5;
  padding: 0 5px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-on-header-muted);
  pointer-events: none;
}

.search-kbd[hidden],
.header-search:focus-within .search-kbd {
  display: none;
}

.site-header--band .search-kbd {
  border-color: rgb(255 255 255 / 0.25);
  color: var(--color-on-band-muted);
}

.header-controls {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.header-npm,
.version-badge {
  font-size: 13px;
  color: var(--color-on-header-muted);
  white-space: nowrap;
}

.header-npm:hover,
.version-badge:hover {
  color: var(--color-on-header);
}

.site-header--band .header-npm,
.site-header--band .version-badge {
  color: var(--color-on-band-muted);
}

.site-header--band .header-npm:hover,
.site-header--band .version-badge:hover,
.site-header--band .theme-toggle {
  color: var(--color-on-band);
}

/* Site Layout (Sidebar + Content)
   ---------------------------------------- */
.site-layout {
  display: flex;
  flex: 1;
  /* Children keep their own height, so the sticky sidebar can stick. */
  align-items: flex-start;
}

/* Main Content
   ---------------------------------------- */
.main-content {
  flex: 1;
  min-width: 0;
  padding: var(--space-8) var(--space-10);
  /* At least viewport-tall, so short pages still put the footer at the
     bottom. */
  min-height: calc(100vh - var(--header-height));
}

/* Theme Toggle (system / light / dark)
   ---------------------------------------- */
.theme-toggle {
  display: flex;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  background-color: transparent;
  color: var(--color-on-header);
  line-height: 1;
  cursor: pointer;
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

/* The icon for the current theme: data-theme is stamped before the first
   paint (no attribute = system). */
.theme-icon {
  display: none;
  width: 1.1rem;
  height: 1.1rem;
}

:root:not([data-theme]) .theme-icon--system,
:root[data-theme='light'] .theme-icon--light,
:root[data-theme='dark'] .theme-icon--dark {
  display: block;
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
  background-color: var(--color-header-search-bg);
  color: var(--color-on-header);
}

/* Search Container
   ---------------------------------------- */
.search-container {
  min-width: 200px;
  max-width: 300px;
}

/* Pagefind UI overrides for the header (PLAN-287 D5): a 32 px box with a
   hairline and 8 px corners; on the band it is see-through. The results
   drawer keeps the page colours. */
.header-search .pagefind-ui {
  --pagefind-ui-scale: 0.7;
  --pagefind-ui-primary: var(--color-link);
  --pagefind-ui-background: var(--color-bg);
  --pagefind-ui-border: var(--color-border);
  --pagefind-ui-border-width: 1px;
  --pagefind-ui-border-radius: var(--radius-lg);
  --pagefind-ui-font: var(--font-sans);
  --pagefind-ui-text: var(--color-text);
  width: 100%;
}

.header-search .pagefind-ui__form {
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
}

.header-search .pagefind-ui__search-input {
  height: 32px !important;
  min-height: 32px !important;
  max-height: 32px !important;
  padding: 0 var(--space-3) !important;
  padding-left: 2rem !important;
  font-size: 12.5px !important;
  font-weight: 400 !important;
  line-height: 30px !important;
  box-sizing: border-box !important;
  background-color: var(--color-header-search-bg) !important;
  border: 1px solid var(--color-border) !important;
  border-radius: var(--radius-lg) !important;
  box-shadow: none !important;
  color: var(--color-on-header) !important;
}

.header-search .pagefind-ui__search-input:hover {
  background-color: var(--color-header-search-bg-hover) !important;
}

/* Typing: the box turns to the page colours. */
.header-search .pagefind-ui__search-input:focus {
  background-color: var(--color-bg) !important;
  color: var(--color-text) !important;
  border-color: var(--color-primary) !important;
  box-shadow: 0 0 0 2px var(--color-primary) !important;
}

.header-search .pagefind-ui__form:focus-within .pagefind-ui__search-input::placeholder {
  color: var(--color-text-muted) !important;
}

.header-search .pagefind-ui__form:focus-within .pagefind-ui__search-clear {
  background-color: transparent !important;
  color: var(--color-text) !important;
}

.header-search .pagefind-ui__form:focus-within::before {
  background-color: var(--color-text) !important;
}

.header-search .pagefind-ui__search-input::placeholder {
  color: var(--color-on-header-muted) !important;
  opacity: 1;
}

.header-search .pagefind-ui__form::before {
  background-color: var(--color-on-header-muted) !important;
  top: 50% !important;
  transform: translateY(-50%) !important;
}

.header-search .pagefind-ui__search-clear {
  background-color: transparent !important;
  color: var(--color-on-header) !important;
  height: 32px !important;
  width: 32px !important;
  padding: 0 !important;
  top: 0 !important;
  transform: none !important;
}

.site-header--band .header-search .pagefind-ui__search-input {
  background-color: var(--color-band-search-bg) !important;
  border-color: rgb(255 255 255 / 0.14) !important;
  color: var(--color-on-band) !important;
}

.site-header--band .header-search .pagefind-ui__search-input::placeholder {
  color: var(--color-on-band-muted) !important;
}

.site-header--band .header-search .pagefind-ui__form::before {
  background-color: var(--color-on-band-muted) !important;
}

.site-header--band .header-search .pagefind-ui__search-clear {
  color: var(--color-on-band) !important;
}

/* Main Content
   ---------------------------------------- */
main {
  flex: 1;
  max-width: var(--max-width-content);
  width: 100%;
  margin: 0 auto;
  padding: var(--space-8) var(--space-6);
}

/* Breadcrumb
   ---------------------------------------- */
.breadcrumb {
  margin-bottom: var(--space-6);
}

.breadcrumb ol {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.breadcrumb li:not(:last-child)::after {
  content: '/';
  color: var(--color-text-light);
}

.breadcrumb a {
  color: var(--color-text-muted);
}

.breadcrumb a:hover {
  color: var(--color-primary);
}

.breadcrumb [aria-current="page"] {
  color: var(--color-text);
  font-weight: 500;
}

/* Site Footer — a full-width near-black bar, white links, as the
   reference's (PLAN-274 D7d).
   ---------------------------------------- */
.site-footer {
  background-color: var(--color-footer-bg);
  padding: var(--space-6);
}

.site-footer nav {
  max-width: var(--max-width-content);
  margin: 0 auto;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  display: flex;
  justify-content: center;
  gap: var(--space-6);
}

.site-footer a {
  color: var(--color-on-footer-muted);
  font-size: var(--text-sm);
}

.site-footer a:hover {
  color: var(--color-on-footer);
}

/* 404 page (standalone: loads tokens + base + shell only)
   ---------------------------------------- */
.not-found {
  max-width: 36rem;
  margin: 18vh auto 0;
  padding: 0 var(--space-6);
  text-align: center;
}

.not-found h1 {
  margin-bottom: var(--space-4);
}

.not-found p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}