.app-shell { display: flex; min-height: 100vh; }
.sidebar { width: var(--sidebar-width); background: var(--bg-card); border-right: 1px solid var(--border); display: flex; flex-direction: column; position: fixed; top: 0; left: 0; height: 100vh; z-index: 100; transition: transform var(--transition); }
.sidebar-header { padding: 1rem; border-bottom: 1px solid var(--border); }
.sidebar-brand { display: flex; align-items: center; gap: 0.75rem; }
.sidebar-logo { width: 32px; height: 32px; }
.sidebar-title { font-weight: 600; font-size: 1.1rem; }
.sidebar-nav { flex: 1; padding: 0.5rem; overflow-y: auto; }
.sidebar-nav a { display: flex; align-items: center; gap: 0.75rem; padding: 0.625rem 0.75rem; border-radius: var(--radius); color: var(--text-secondary); font-size: 0.9rem; transition: all var(--transition); text-decoration: none; cursor: pointer; }
.sidebar-nav a:hover { background: var(--border-light); color: var(--text); text-decoration: none; }
.sidebar-nav a.active { background: var(--primary); color: white; }
.sidebar-nav a.active svg { stroke: white; }
.sidebar-nav svg { stroke: var(--text-muted); flex-shrink: 0; transition: stroke var(--transition); }
.sidebar-nav a:hover svg { stroke: var(--text-secondary); }
.sidebar-nav a.active svg { stroke: white; }
.nav-group-items { max-height: 0; overflow: hidden; transition: max-height 0.25s ease; }
.nav-group.open .nav-group-items { max-height: 500px; }
.nav-group-items a { padding-left: 2.75rem; font-size: 0.85rem; }
.nav-group-toggle { cursor: pointer; }
.nav-chevron { margin-left: auto; transition: transform 0.2s ease; display: flex; align-items: center; }
.nav-group.open .nav-chevron { transform: rotate(90deg); }
.nav-group-toggle svg:first-child { stroke: var(--text-muted); }
.nav-group.open > .nav-group-toggle { background: var(--border-light); color: var(--text); }
.sidebar-footer { padding: 0.75rem; border-top: 1px solid var(--border); }
.sidebar-user { display: flex; align-items: center; gap: 0.5rem; font-size: 0.85rem; }
.main-wrapper { flex: 1; margin-left: var(--sidebar-width); display: flex; flex-direction: column; min-height: 100vh; }
.main-header { height: var(--header-height); background: var(--bg-card); border-bottom: 1px solid var(--border); display: flex; align-items: center; padding: 0 1.5rem; gap: 1rem; position: sticky; top: 0; z-index: 50; }
.sidebar-toggle { display: none; background: none; border: none; cursor: pointer; padding: 0.5rem; }
.sidebar-toggle span { display: block; width: 20px; height: 2px; background: var(--text); margin: 4px 0; border-radius: 1px; }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 0.5rem; }
.header-btn { background: none; border: 1px solid var(--border); border-radius: var(--radius); padding: 0.5rem; cursor: pointer; color: var(--text-secondary); }
.header-btn:hover { background: var(--border-light); }
.content-area { flex: 1; padding: 1.5rem; }
.sidebar-overlay { display: none; }
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .sidebar-overlay.open { display: block; position: fixed; inset: 0; background: rgba(0,0,0,0.3); z-index: 99; }
  .main-wrapper { margin-left: 0; }
  .sidebar-toggle { display: block; }
}