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

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

.sidebar-header {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.sidebar-header .logo {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.sidebar-header h1 {
  font-size: var(--fs-md);
  font-weight: var(--fw-bold);
  white-space: nowrap;
}

.sidebar-header .subtitle {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  display: block;
}

.sidebar-nav {
  flex: 1;
  padding: var(--space-md) 0;
  overflow-y: auto;
}

.nav-section {
  padding: var(--space-xs) var(--space-lg);
  margin-top: var(--space-md);
}

.nav-section:first-child {
  margin-top: 0;
}

.nav-section-title {
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: var(--space-xs);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  margin: 2px 0;
  border-radius: var(--border-radius-sm);
  color: var(--text-secondary);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  transition: all var(--transition-fast);
  cursor: pointer;
}

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

.nav-item.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: var(--fw-semibold);
}

.nav-item .nav-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.7;
}

.nav-item.active .nav-icon {
  opacity: 1;
}

.sidebar-footer {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--border-color);
}

/* Main Content */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
}

.main-header {
  height: var(--header-height);
  padding: 0 var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 50;
}

.main-header-left {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.main-header-right {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.menu-toggle {
  display: none;
  padding: var(--space-sm);
  border-radius: var(--border-radius-sm);
}

.menu-toggle:hover {
  background: var(--bg-tertiary);
}

.view-container {
  padding: var(--space-xl);
  max-width: 1200px;
  margin: 0 auto;
}

/* Grid utilities */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

/* Mobile sidebar overlay */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 99;
}

.sidebar-overlay.active {
  display: block;
}