.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 250px 1fr;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    "sidebar header"
    "sidebar main"
    "sidebar footer";
  max-width: var(--max-width);
  margin: 0 auto;
}

.sidebar {
  grid-area: sidebar;
  background: rgba(22, 27, 34, 0.98);
  border-right: 1px solid var(--color-border);
  min-height: 100vh;
  padding: 1.5rem 1rem;
}

.sidebar .brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.sidebar .brand strong {
  font-size: 1.15rem;
}

.sidebar nav {
  display: grid;
  gap: 0.75rem;
}

.sidebar a {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.95rem 1rem;
  border-radius: 14px;
  color: var(--color-text-secondary);
  transition: background var(--transition), color var(--transition);
}

.sidebar a.active {
  background: rgba(210, 153, 34, 0.2);
  color: var(--color-text-primary);
}

.main-header {
  grid-area: header;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.4rem 1.5rem;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  background: rgba(13, 17, 23, 0.9);
}

.main-header h1 {
  font-size: 1.1rem;
}

.main-header .header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-badge {
  padding: 0.55rem 0.85rem;
  border-radius: 999px;
  background: rgba(88, 166, 255, 0.12);
  color: var(--color-text-primary);
}

.content {
  grid-area: main;
  padding: 1.5rem;
  background: transparent;
}

.footer {
  grid-area: footer;
  padding: 1rem 1.5rem;
  text-align: center;
  color: var(--color-text-secondary);
  border-top: 1px solid rgba(255,255,255,0.05);
}

.page-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.page-title h2 {
  font-size: clamp(1.25rem, 2vw, 1.75rem);
}

.section-group {
  display: grid;
  gap: 1.25rem;
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-1 {
  grid-template-columns: 1fr;
}

.card-small {
  min-height: 132px;
}

.alert-card {
  border-left: 4px solid var(--color-warning);
}

.page-inner {
  display: grid;
  gap: 1.5rem;
}

.tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tab-button {
  border: 1px solid var(--color-border);
  background: rgba(255,255,255,0.04);
  color: var(--color-text-primary);
  border-radius: 999px;
  padding: 0.75rem 1rem;
}

.tab-button.active {
  background: rgba(88, 166, 255, 0.14);
  border-color: rgba(88, 166, 255, 0.35);
}

.table-card {
  overflow-x: auto;
}

.card-grid-mobile {
  display: grid;
  gap: 1rem;
}