/* KHub layout — sidebar, topbar, content shell, mobile drawer (§7).
   Load order: tokens → base → layout → components. */

/* ---------- App shell ---------- */
.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  grid-template-rows: var(--topbar-h) minmax(0, 1fr);
  grid-template-areas:
    "sidebar topbar"
    "sidebar content";
  min-height: 100vh;
  min-height: 100dvh;
  background: var(--bg);
}

/* Collapsed sidebar: icons only, 64px (§7) */
.app.is-sidebar-collapsed {
  --sidebar-w: 64px;
}

/* ---------- Sidebar ---------- */
.sidebar {
  grid-area: sidebar;
  position: sticky;
  top: 0;
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow: hidden;
  z-index: 30;
  /* §8: width is never animated — collapse is instant, labels fade */
}

.sidebar__logo {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  height: var(--topbar-h);
  padding: 0 var(--sp-4);
  flex-shrink: 0;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-weight: var(--fw-semibold);
  font-size: var(--fs-base);
  white-space: nowrap;
  overflow: hidden;
}

.sidebar__logo svg {
  width: 22px;
  height: 22px;
  color: var(--accent-600);
}

.sidebar__logo-text {
  transition: opacity var(--dur-fast) var(--ease);
}

.sidebar__nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--sp-3) var(--sp-2);
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}

.sidebar__group {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar__group-title {
  padding: var(--sp-2) var(--sp-3) var(--sp-1);
  font-size: var(--fs-xs);
  line-height: var(--lh-xs);
  font-weight: var(--fw-medium);
  color: var(--text-subtle);
  white-space: nowrap;
  overflow: hidden;
  text-transform: none; /* §6.4/§13: uppercase forbidden */
  transition: opacity var(--dur-fast) var(--ease);
}

/* Nav item */
.sidebar__item {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  height: 36px;
  padding: 0 var(--sp-3);
  border-radius: var(--r-sm);
  color: var(--text-muted);
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  white-space: nowrap;
  overflow: hidden;
  text-decoration: none;
  transition:
    background-color var(--dur-fast) var(--ease),
    color var(--dur-fast) var(--ease);
}

.sidebar__item:hover {
  background: var(--surface-2);
  color: var(--text);
  text-decoration: none;
}

.sidebar__item:active {
  background: var(--surface-2);
}

.sidebar__item:focus-visible {
  outline: 2px solid var(--accent-500);
  outline-offset: 1px;
}

.sidebar__item svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.sidebar__item-text {
  transition: opacity var(--dur-fast) var(--ease);
}

/* Active item: accent bg + 3px left bar (§7) */
.sidebar__item.is-active {
  background: var(--accent-50);
  color: var(--accent-600);
}

.sidebar__item.is-active::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 18px;
  border-radius: 0 var(--r-full) var(--r-full) 0;
  background: var(--accent-500);
}

/* Sidebar footer / collapse toggle */
.sidebar__footer {
  flex-shrink: 0;
  padding: var(--sp-2);
  border-top: 1px solid var(--border);
}

.sidebar__toggle {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  width: 100%;
  height: 36px;
  padding: 0 var(--sp-3);
  border-radius: var(--r-sm);
  color: var(--text-muted);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  transition:
    background-color var(--dur-fast) var(--ease),
    color var(--dur-fast) var(--ease);
}

.sidebar__toggle:hover {
  background: var(--surface-2);
  color: var(--text);
}

.sidebar__toggle:focus-visible {
  outline: 2px solid var(--accent-500);
  outline-offset: 1px;
}

.sidebar__toggle svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  transition: transform var(--dur-base) var(--ease);
}

.sidebar__toggle-text {
  transition: opacity var(--dur-fast) var(--ease);
}

/* Collapsed state: hide labels, center icons (§7) */
.app.is-sidebar-collapsed .sidebar__logo-text,
.app.is-sidebar-collapsed .sidebar__group-title,
.app.is-sidebar-collapsed .sidebar__item-text,
.app.is-sidebar-collapsed .sidebar__toggle-text {
  opacity: 0;
  width: 0;
  overflow: hidden;
  pointer-events: none;
}

.app.is-sidebar-collapsed .sidebar__item,
.app.is-sidebar-collapsed .sidebar__toggle,
.app.is-sidebar-collapsed .sidebar__logo {
  justify-content: center;
  padding-left: 0;
  padding-right: 0;
}

.app.is-sidebar-collapsed .sidebar__toggle svg {
  transform: rotate(180deg);
}

.app.is-sidebar-collapsed .sidebar__nav {
  padding-left: var(--sp-1);
  padding-right: var(--sp-1);
}

/* ---------- Topbar (§7) ---------- */
.topbar {
  grid-area: topbar;
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  height: var(--topbar-h);
  padding: 0 var(--sp-8);
  background: color-mix(in srgb, var(--surface) 80%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.topbar__left {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-width: 0;
}

.topbar__right {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-left: auto;
}

.topbar__search {
  flex: 0 1 260px;
  min-width: 0;
}

.topbar__status {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--text-muted);
  white-space: nowrap;
}

/* Drawer open button — hidden on desktop */
.topbar__menu-btn {
  display: none;
}

/* ---------- Breadcrumbs ---------- */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  min-width: 0;
  font-size: var(--fs-sm);
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
}

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

.breadcrumbs a:hover {
  color: var(--text);
  text-decoration: none;
}

.breadcrumbs__sep {
  color: var(--text-subtle);
  user-select: none;
}

.breadcrumbs__current {
  color: var(--text);
  font-weight: var(--fw-medium);
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ---------- Content ---------- */
.content {
  grid-area: content;
  min-width: 0;
  padding: var(--sp-6) var(--sp-8); /* 24–32px (§7) */
}

.content__inner {
  max-width: var(--content-max); /* 1440px */
  margin: 0 auto;
}

/* Page header block inside content */
.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--sp-4);
  margin-bottom: var(--sp-6);
  flex-wrap: wrap;
}

.page-header__title {
  font-size: var(--fs-xl);
  line-height: var(--lh-xl);
  font-weight: var(--fw-semibold);
  color: var(--text);
}

.page-header__desc {
  margin-top: var(--sp-1);
  font-size: var(--fs-base);
  color: var(--text-muted);
  max-width: 68ch;
}

.page-header__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  flex-shrink: 0;
}

/* ---------- Mobile drawer (<900px, §7) ---------- */
.sidebar-backdrop {
  display: none;
}

@media (max-width: 899px) {
  .app {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas:
      "topbar"
      "content";
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-w);
    height: 100vh;
    height: 100dvh;
    transform: translateX(-100%);
    box-shadow: none;
    transition: transform var(--dur-base) var(--ease);
    z-index: 50;
  }

  .app.is-drawer-open .sidebar {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }

  /* Backdrop behind drawer */
  .sidebar-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 40;
    background: rgba(11, 13, 18, .45);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    opacity: 0;
    visibility: hidden;
    transition:
      opacity var(--dur-base) var(--ease),
      visibility var(--dur-base) var(--ease);
  }

  .app.is-drawer-open .sidebar-backdrop {
    opacity: 1;
    visibility: visible;
  }

  /* On mobile the sidebar always shows labels (no collapse) */
  .app.is-sidebar-collapsed .sidebar__logo-text,
  .app.is-sidebar-collapsed .sidebar__group-title,
  .app.is-sidebar-collapsed .sidebar__item-text,
  .app.is-sidebar-collapsed .sidebar__toggle-text {
    opacity: 1;
    width: auto;
    overflow: visible;
    pointer-events: auto;
  }

  .app.is-sidebar-collapsed .sidebar__item,
  .app.is-sidebar-collapsed .sidebar__toggle,
  .app.is-sidebar-collapsed .sidebar__logo {
    justify-content: flex-start;
    padding-left: var(--sp-3);
    padding-right: var(--sp-3);
  }

  .app.is-sidebar-collapsed .sidebar__toggle svg {
    transform: none;
  }

  /* Show hamburger, hide collapse toggle */
  .topbar__menu-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    flex-shrink: 0;
    border-radius: var(--r-sm);
    color: var(--text-muted);
    transition: background-color var(--dur-fast) var(--ease);
  }

  .topbar__menu-btn:hover {
    background: var(--surface-2);
    color: var(--text);
  }

  .topbar__menu-btn:focus-visible {
    outline: 2px solid var(--accent-500);
    outline-offset: 2px;
  }

  .topbar {
    padding: 0 var(--sp-4);
  }

  .topbar__search {
    display: none;
  }

  .content {
    padding: var(--sp-4);
  }

  .sidebar__footer {
    display: none;
  }

  /* §11: touch targets ≥ 44px on mobile */
  .sidebar__item {
    height: 44px;
  }
}

/* ---------- Narrow phones (<560px) ---------- */
@media (max-width: 559px) {
  .page-header {
    flex-direction: column;
    align-items: stretch;
  }

  .page-header__actions {
    flex-wrap: wrap;
  }

  .topbar__status {
    display: none;
  }
}

/* ---------- 1366×768 safety: keep content usable (§13) ---------- */
@media (min-width: 900px) and (max-width: 1440px) {
  .content {
    padding: var(--sp-5) var(--sp-6);
  }
}