/**
 * TundraFox Dashboard — Application shell layout.
 *
 * CSS Grid with three regions:
 *   header  header
 *   sidebar main
 *
 * Collapses to a single column at <768px (sidebar moves above main).
 */

.app-shell {
  display: grid;
  grid-template-columns: 240px 1fr;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    'header header'
    'sidebar main'
    'footer footer';
  min-height: 100vh;
}

.app-shell__header {
  grid-area: header;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-3) var(--spacing-6);
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  box-shadow: var(--shadow-sm);
}

.app-shell__brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

.app-shell__logo {
  width: auto;
  height: 28px;
}

.app-shell__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
}

.app-shell__header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.app-shell__sidebar {
  grid-area: sidebar;
  background: var(--color-white);
  border-right: 1px solid var(--color-gray-200);
  padding: var(--spacing-4) 0;
}

.nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
}

.nav-list a {
  display: block;
  padding: var(--spacing-3) var(--spacing-6);
  color: var(--color-gray-800);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
  border-left: 3px solid transparent;
}

.nav-list a:hover,
.nav-list a:focus {
  background: var(--color-gray-100);
  color: var(--color-primary);
}

.nav-list a[aria-current='page'] {
  border-left-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-gray-100);
  font-weight: var(--font-weight-semibold);
}

.app-shell__main {
  grid-area: main;
  padding: var(--spacing-8);
  outline: none;
}

#route-outlet {
  max-width: 960px;
}

.toast-region {
  position: fixed;
  bottom: var(--spacing-6);
  right: var(--spacing-6);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
  z-index: 1000;
}

.app-shell__footer {
  grid-area: footer;
  padding: var(--spacing-3) var(--spacing-6);
  background: var(--color-white);
  border-top: 1px solid var(--color-gray-200);
  font-size: var(--font-size-sm);
  color: var(--color-gray-600);
  text-align: center;
}

.app-shell__footer a {
  color: var(--color-primary);
  text-decoration: none;
  padding: 0 var(--spacing-2);
}

.app-shell__footer a:hover,
.app-shell__footer a:focus-visible {
  text-decoration: underline;
}

@media (max-width: 767px) {
  .app-shell {
    grid-template-columns: 1fr;
    grid-template-areas:
      'header'
      'sidebar'
      'main'
      'footer';
  }

  .app-shell__sidebar {
    border-right: none;
    border-bottom: 1px solid var(--color-gray-200);
    padding: var(--spacing-2) 0;
  }

  .nav-list {
    flex-direction: row;
    overflow-x: auto;
  }

  .nav-list a {
    padding: var(--spacing-3) var(--spacing-4);
    border-left: none;
    border-bottom: 3px solid transparent;
    white-space: nowrap;
  }

  .nav-list a[aria-current='page'] {
    border-left: none;
    border-bottom-color: var(--color-primary);
  }
}