/* ===== Layout: Shell, Sidebar, Topbar, Content ===== */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: var(--leading-normal);
  -webkit-font-smoothing: antialiased;
}

/* ---------- Login layout (no shell) ---------- */
.login-layout {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, var(--color-dark) 0%, #1a3148 100%);
}

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

/* Sidebar */
.sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: var(--sidebar-width);
  background: var(--color-dark);
  color: var(--color-text-inverse);
  display: flex;
  flex-direction: column;
  z-index: var(--z-sidebar);
  transition: transform var(--transition-normal);
  overflow-y: auto;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6) var(--space-5);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.sidebar-brand-icon {
  width: 36px; height: 44px;
  flex-shrink: 0;
}

.sidebar-brand-text {
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.sidebar-brand-sub {
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.5);
  font-weight: var(--font-normal);
}

.sidebar-nav { flex: 1; padding: var(--space-4) 0; }

.nav-group-label {
  padding: var(--space-2) var(--space-5);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: rgba(255,255,255,0.35);
  margin-top: var(--space-4);
}

.nav-group-label svg { width: 14px; height: 14px; flex-shrink: 0; opacity: 0.5; }

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-5);
  color: rgba(255,255,255,0.7);
  text-decoration: none;
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  border-left: 3px solid transparent;
  transition: all var(--transition-fast);
  cursor: pointer;
}

.nav-item:hover {
  color: #fff;
  background: rgba(255,255,255,0.06);
}

.nav-item.active {
  color: #fff;
  background: rgba(255,255,255,0.1);
  border-left-color: var(--color-primary);
}

.nav-item svg { width: 18px; height: 18px; flex-shrink: 0; opacity: 0.7; }
.nav-item.active svg { opacity: 1; }

/* Topbar */
.topbar {
  position: fixed;
  top: 0;
  left: var(--sidebar-width);
  right: 0;
  height: var(--topbar-height);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-6);
  z-index: var(--z-topbar);
}

.topbar-title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.topbar-user {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-sm);
}

.topbar-avatar {
  width: 32px; height: 32px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  display: flex; align-items: center; justify-content: center;
  font-size: var(--text-xs);
  font-weight: var(--font-bold);
}

.topbar-user-name { font-weight: var(--font-medium); }

.topbar-user-role {
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
}

/* Mobile toggle */
.sidebar-toggle {
  display: none;
  background: none; border: none; color: var(--color-text);
  cursor: pointer; padding: var(--space-2);
}

/* Content */
.main-content {
  margin-left: var(--sidebar-width);
  margin-top: var(--topbar-height);
  padding: var(--space-6);
  flex: 1;
  min-height: calc(100vh - var(--topbar-height));
}

/* Sidebar backdrop for mobile */
.sidebar-backdrop {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: calc(var(--z-sidebar) - 1);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .sidebar.open ~ .sidebar-backdrop { display: block; }
  .sidebar-toggle { display: block; }
  .topbar { left: 0; }
  .main-content { margin-left: 0; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .page-header { flex-direction: column; align-items: flex-start; gap: var(--space-3); }
}