/* App shell */
.app-layout {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: var(--z-sidebar);
  transition: width var(--transition-base), transform var(--transition-base);
  overflow: hidden;
}

.sidebar-header {
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  padding: 0 20px;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.sidebar-header .logo {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 12px;
}

.sidebar-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  font-weight: 500;
  white-space: nowrap;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.sidebar-nav-item:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.sidebar-nav-item.active {
  background: rgba(59, 130, 246, 0.12);
  color: var(--accent-primary);
}

.sidebar-nav-item .icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sidebar-nav-section {
  padding: 16px 12px 6px;
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--border-color);
  flex-shrink: 0;
}

/* Collapsed sidebar */
.sidebar.collapsed {
  width: var(--sidebar-collapsed-width);
}

.sidebar.collapsed .sidebar-nav-item span,
.sidebar.collapsed .sidebar-nav-section,
.sidebar.collapsed .sidebar-header .logo span {
  display: none;
}

.sidebar.collapsed .sidebar-nav-item {
  justify-content: center;
  padding: 10px;
}

/* Main content area */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: margin-left var(--transition-base);
}

.sidebar.collapsed ~ .main-content {
  margin-left: var(--sidebar-collapsed-width);
}

/* Topbar */
.topbar {
  position: sticky;
  top: 0;
  height: var(--topbar-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: var(--z-sticky);
  flex-shrink: 0;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.sidebar-toggle:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

/* Page content */
.page-content {
  flex: 1;
  padding: 24px;
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
}

.page-header h1 {
  font-size: var(--text-2xl);
  color: var(--text-primary);
}

/* Mobile overlay */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: calc(var(--z-sidebar) - 1);
}

/* Responsive */
@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.mobile-open {
    transform: translateX(0);
  }
  .sidebar.mobile-open ~ .sidebar-overlay {
    display: block;
  }
  .main-content {
    margin-left: 0;
  }
  .sidebar.collapsed ~ .main-content {
    margin-left: 0;
  }
}

@media (max-width: 768px) {
  .page-content {
    padding: 16px;
  }
  .topbar {
    padding: 0 16px;
  }
  .page-header {
    flex-direction: column;
    align-items: flex-start;
  }
}