/* ============================================================
   NCLEX Pro LMS — Layout CSS
   Sidebar, Topbar, Main Content, Page Headers, Grid
   ============================================================ */

/* ── App Shell ───────────────────────────────────────────── */
.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: var(--topbar-height) 1fr;
  min-height: 100vh;
  position: relative;
  z-index: 1;
}

/* ── Sidebar ─────────────────────────────────────────────── */
.sidebar {
  grid-column: 1;
  grid-row: 1 / 3;
  width: var(--sidebar-width);
  height: 100vh;
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-right: var(--glass-border);
  padding: var(--space-5) 0;
  overflow-y: auto;
  z-index: 100;
  transition: transform 0.3s ease;
}

.sidebar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 0 var(--space-6) var(--space-6);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: var(--space-4);
  text-decoration: none;
}

.sidebar-logo-icon {
  width: 40px; height: 40px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
  box-shadow: 0 4px 16px rgba(79,142,247,0.35);
}

.sidebar-logo-text {
  display: flex;
  flex-direction: column;
}
.sidebar-logo-name {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
}
.sidebar-logo-sub {
  font-size: 0.68rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 2px;
}

.sidebar-section {
  padding: var(--space-3) var(--space-5) var(--space-2);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 11px var(--space-5);
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 500;
  border-radius: 0;
  cursor: pointer;
  transition: var(--transition-fast);
  text-decoration: none;
  position: relative;
  margin: 1px var(--space-3);
  border-radius: var(--radius-md);
}

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

.nav-item.active {
  background: var(--color-primary-glow);
  color: var(--color-primary);
  font-weight: 600;
}

.nav-item.active::before {
  content: '';
  position: absolute;
  left: -8px; top: 50%;
  transform: translateY(-50%);
  width: 3px; height: 60%;
  background: var(--color-primary);
  border-radius: var(--radius-full);
}

.nav-item .nav-icon {
  width: 20px;
  text-align: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.nav-item .nav-badge {
  margin-left: auto;
  background: var(--color-danger);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: var(--radius-full);
  min-width: 18px;
  text-align: center;
}

.sidebar-footer {
  margin-top: auto;
  padding: var(--space-4) var(--space-3);
  border-top: 1px solid var(--border-color);
}

.sidebar-user {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-3);
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
  cursor: pointer;
  text-decoration: none;
}
.sidebar-user:hover { background: var(--color-bg-hover); }
.sidebar-user-info { flex: 1; min-width: 0; }
.sidebar-user-name { font-size: 0.88rem; font-weight: 600; color: var(--text-primary); truncate: true; }
.sidebar-user-role { font-size: 0.73rem; color: var(--text-muted); text-transform: capitalize; }

/* ── Topbar ──────────────────────────────────────────────── */
.topbar {
  grid-column: 2;
  grid-row: 1;
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-8);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border-bottom: var(--glass-border);
  position: sticky;
  top: 0;
  z-index: 50;
}

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

.topbar-title {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* Search bar */
.topbar-search {
  display: flex;
  align-items: center;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 8px 16px;
  gap: var(--space-3);
  min-width: 240px;
  transition: var(--transition-fast);
}
.topbar-search:focus-within {
  border-color: var(--color-primary);
  background: rgba(79,142,247,0.05);
}
.topbar-search input {
  background: none;
  border: none;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.88rem;
  width: 100%;
  outline: none;
}
.topbar-search input::placeholder { color: var(--text-muted); }
.topbar-search .search-icon { color: var(--text-muted); font-size: 0.95rem; }

/* Notification bell */
.notification-btn {
  position: relative;
  width: 38px; height: 38px;
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition-fast);
}
.notification-btn:hover { background: var(--color-bg-hover); color: var(--text-primary); }
.notification-badge {
  position: absolute;
  top: -4px; right: -4px;
  width: 16px; height: 16px;
  background: var(--color-danger);
  border-radius: 50%;
  font-size: 0.65rem;
  font-weight: 700;
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  border: 2px solid var(--color-bg-dark);
}

/* ── Main Content ────────────────────────────────────────── */
.main-content {
  grid-column: 2;
  grid-row: 2;
  padding: var(--space-8);
  max-width: 1400px;
  overflow-x: hidden;
}

/* ── Page Header ─────────────────────────────────────────── */
.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-8);
}

.page-header-left { flex: 1; }

.page-title {
  font-family: var(--font-heading);
  font-size: clamp(1.4rem, 3vw, 1.8rem);
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}

.page-subtitle {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0;
}

.page-header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

/* ── Grid Layouts ────────────────────────────────────────── */
.grid {
  display: grid;
  gap: var(--space-6);
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-auto { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.grid-stats { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }

/* ── Breadcrumb ──────────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb-sep { color: var(--text-muted); opacity: 0.4; }
.breadcrumb-current { color: var(--text-secondary); font-weight: 500; }

/* ── Empty State ─────────────────────────────────────────── */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-16) var(--space-8);
  text-align: center;
  gap: var(--space-4);
}
.empty-state-icon {
  width: 72px; height: 72px;
  border-radius: 50%;
  background: rgba(255,255,255,0.05);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.8rem;
  color: var(--text-muted);
}
.empty-state h3 { color: var(--text-secondary); font-size: 1.1rem; }
.empty-state p   { color: var(--text-muted); max-width: 360px; }

/* ── Sidebar mobile ──────────────────────────────────────── */
.mobile-menu-toggle {
  display: none;
  background: none; border: none;
  color: var(--text-secondary);
  font-size: 1.3rem; cursor: pointer;
  padding: var(--space-2);
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 1024px) {
  :root { --sidebar-width: 240px; }
  .main-content { padding: var(--space-6); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .app-shell {
    grid-template-columns: 1fr;
    grid-template-rows: var(--topbar-height) 1fr;
  }

  .sidebar {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    z-index: 300;
    transform: translateX(-100%);
  }
  .sidebar.open { transform: translateX(0); }

  .topbar { grid-column: 1; padding: 0 var(--space-5); }
  .main-content {
    grid-column: 1;
    padding: var(--space-4);
    padding-bottom: var(--space-12);
  }

  .mobile-menu-toggle { display: flex; }
  .topbar-search { display: none; }
  .page-header { flex-direction: column; align-items: stretch; }
  .page-header-actions { flex-wrap: wrap; }

  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .grid-stats { grid-template-columns: repeat(2, 1fr); }

  .table-wrapper { font-size: 0.82rem; }
}

@media (max-width: 480px) {
  .grid-stats { grid-template-columns: 1fr; }
}

/* ── Mobile overlay ──────────────────────────────────────── */
.sidebar-overlay {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 299;
}
.sidebar-overlay.active { display: block; }