/* DESIGN.md §8 — layouts (sidebar, app-shell, header) */
.sidebar {
  position: fixed; top: 0; left: 0; bottom: 0;
  width: var(--sidebar-w);
  background: var(--pc-primary);
  color: var(--pc-white);
  padding: var(--space-5) var(--space-3);
  display: flex; flex-direction: column; gap: var(--space-5);
  z-index: 5;
}
.brand {
  display: flex; align-items: center; gap: var(--space-2);
  text-decoration: none; color: var(--pc-white);
  padding: 0 var(--space-3) var(--space-4);
  border-bottom: 1px solid rgba(255,255,255,0.12);
}
.brand__logo { height: 36px; width: auto; }
.brand__suffix {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--pc-peach);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-left: auto;
}
.nav { display: flex; flex-direction: column; gap: var(--space-1); }
.nav__label {
  font-family: var(--font-display-regular);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-widest);
  color: rgba(255,255,255,0.5);
  padding: var(--space-3) var(--space-3) var(--space-1);
}
.nav__item {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.78);
  text-decoration: none;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: color var(--dur-fast), background var(--dur-fast);
}
.nav__item:hover { background: rgba(255,255,255,0.08); color: var(--pc-white); }
.nav__item--active {
  color: var(--pc-white);
  background: rgba(255,255,255,0.10);
  border-left-color: var(--pc-peach);
  font-weight: 600;
}

.app-shell { padding-left: var(--sidebar-w); min-height: 100vh; }
.app-header {
  position: sticky; top: 0; z-index: 10;
  height: var(--header-h);
  background: var(--pc-paper);
  border-bottom: 1px solid var(--pc-line);
  display: flex; align-items: center;
  padding: 0 var(--space-6);
  gap: var(--space-5);
}
.breadcrumbs {
  font-family: var(--font-display-regular);
  font-size: var(--text-sm);
  color: var(--pc-secondary);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
}
.breadcrumbs a { color: var(--pc-primary); text-decoration: none; }
.breadcrumbs a:hover { text-decoration: underline; }
.app-main { padding: var(--space-6); background: var(--pc-paper); min-height: calc(100vh - var(--header-h)); }

/* Admin overrides */
.admin-shell::before {
  content: ''; position: fixed; top: 0; left: 0; right: 0;
  height: 3px; background: var(--pc-peach); z-index: 100;
}
.admin-shell .table tbody td { padding: var(--space-2) var(--space-3); }

@media (max-width: 720px) {
  .sidebar { width: 100%; height: auto; position: sticky; top: 0; bottom: auto;
             flex-direction: row; flex-wrap: wrap; gap: var(--space-2); padding: var(--space-3); }
  .nav { flex-direction: row; flex-wrap: wrap; gap: var(--space-2); }
  .nav__label { display: none; }
  .app-shell { padding-left: 0; }
}