/* layout.css — application shell: sidebar, navbar, page header, breadcrumbs,
 * content region, and responsive behaviour (collapsible sidebar). */

.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: 100vh;
  min-height: 100vh;
}
.app-shell[data-sidebar="collapsed"] {
  grid-template-columns: var(--sidebar-width-collapsed) 1fr;
}

/* ===================== Sidebar ===================== */
.sidebar {
  grid-column: 1;
  background: var(--sidebar-bg);
  color: var(--sidebar-text);
  display: flex;
  flex-direction: column;
  min-height: 0;
  z-index: var(--z-sidebar);
  transition: width var(--dur-med) var(--ease);
}
.sidebar__brand {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  height: var(--navbar-height);
  padding: 0 var(--sp-4);
  flex: 0 0 auto;
  color: #fff;
  font-weight: var(--fw-bold);
  font-size: var(--fs-lg);
  letter-spacing: 0.02em;
  white-space: nowrap;
  overflow: hidden;
}
.sidebar__brand-mark {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  background: var(--sidebar-accent);
  color: #fff;
  border-radius: var(--radius-md);
  font-weight: var(--fw-bold);
}
.sidebar__nav {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  padding: var(--sp-3) var(--sp-2);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.sidebar__section {
  padding: var(--sp-4) var(--sp-3) var(--sp-2);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--sidebar-text-muted);
}
.nav-item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3);
  border-radius: var(--radius-md);
  color: var(--sidebar-text);
  font-weight: var(--fw-medium);
  white-space: nowrap;
  overflow: hidden;
}
.nav-item:hover {
  background: var(--sidebar-active-bg);
  color: var(--sidebar-active-text);
  text-decoration: none;
}
.nav-item[aria-current="page"] {
  background: var(--sidebar-active-bg);
  color: var(--sidebar-active-text);
  box-shadow: inset 3px 0 0 0 var(--sidebar-accent);
}
.nav-item__icon {
  flex: 0 0 auto;
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
}
.nav-item__label {
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Collapsed rail: hide text, centre icons. */
[data-sidebar="collapsed"] .sidebar__brand-text,
[data-sidebar="collapsed"] .nav-item__label,
[data-sidebar="collapsed"] .sidebar__section {
  display: none;
}
[data-sidebar="collapsed"] .nav-item {
  justify-content: center;
}

/* ===================== Main column ===================== */
.main {
  grid-column: 2;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
}

/* ===================== Top navbar ===================== */
.navbar {
  flex: 0 0 auto;
  height: var(--navbar-height);
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: 0 var(--sp-5);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  z-index: var(--z-navbar);
}
.navbar__title {
  font-weight: var(--fw-semibold);
  color: var(--text-strong);
}
.navbar__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}
.ws-indicator {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--text-muted);
  padding: var(--sp-1) var(--sp-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
}
.ws-indicator__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
}
.ws-indicator[data-state="open"] .ws-indicator__dot {
  background: var(--success);
}
.ws-indicator[data-state="connecting"] .ws-indicator__dot,
.ws-indicator[data-state="reconnecting"] .ws-indicator__dot {
  background: var(--warning);
  animation: pulse 1s var(--ease) infinite;
}
.ws-indicator[data-state="closed"] .ws-indicator__dot,
.ws-indicator[data-state="error"] .ws-indicator__dot {
  background: var(--danger);
}
@keyframes pulse {
  50% {
    opacity: 0.35;
  }
}

/* ===================== Content region ===================== */
.content {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  padding: var(--sp-6);
}
.content__inner {
  max-width: var(--content-max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--sp-6);
}

/* ===================== Breadcrumbs + page header ===================== */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--text-muted);
}
.breadcrumbs a {
  color: var(--text-muted);
}
.breadcrumbs a:hover {
  color: var(--brand);
}
.breadcrumbs__sep {
  color: var(--border-strong);
}
.breadcrumbs__current {
  color: var(--text);
  font-weight: var(--fw-medium);
}

.page-header {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-4);
  flex-wrap: wrap;
}
.page-header__titles {
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
  min-width: 0;
}
.page-header__title {
  font-size: var(--fs-2xl);
  font-weight: var(--fw-bold);
  color: var(--text-strong);
  line-height: var(--lh-tight);
}
.page-header__subtitle {
  color: var(--text-muted);
}
.page-header__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-left: auto;
}

/* Hamburger only appears on small screens. */
.navbar__menu-btn {
  display: none;
}

/* Sidebar backdrop (mobile drawer). */
.sidebar-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--backdrop);
  z-index: var(--z-backdrop);
}

/* ===================== Responsive ===================== */

/* Tablet: default the sidebar to the collapsed rail. */
@media (max-width: 1024px) {
  .app-shell,
  .app-shell[data-sidebar="collapsed"] {
    grid-template-columns: var(--sidebar-width-collapsed) 1fr;
  }
  [data-sidebar="expanded"].app-shell {
    grid-template-columns: var(--sidebar-width) 1fr;
  }
  [data-sidebar="expanded"] .sidebar__brand-text,
  [data-sidebar="expanded"] .nav-item__label,
  [data-sidebar="expanded"] .sidebar__section {
    display: revert;
  }
  [data-sidebar="expanded"] .nav-item {
    justify-content: flex-start;
  }
}

/* Mobile: sidebar becomes an off-canvas drawer toggled by the hamburger. */
@media (max-width: 768px) {
  .app-shell,
  .app-shell[data-sidebar] {
    grid-template-columns: 1fr;
  }
  .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: var(--sidebar-width);
    transform: translateX(-100%);
    transition: transform var(--dur-med) var(--ease);
    box-shadow: var(--shadow-lg);
  }
  /* On mobile the drawer shows full labels regardless of collapse state. */
  .sidebar__brand-text,
  .nav-item__label,
  .sidebar__section {
    display: revert;
  }
  .nav-item {
    justify-content: flex-start;
  }
  [data-sidebar="open"] .sidebar {
    transform: translateX(0);
  }
  [data-sidebar="open"] .sidebar-backdrop {
    display: block;
  }
  .main {
    grid-column: 1;
  }
  .navbar__menu-btn {
    display: inline-flex;
  }
  .content {
    padding: var(--sp-4);
  }
  .page-header__actions {
    margin-left: 0;
  }
}