:root {
  --sidebar-width: 250px;
}

body {
  min-height: 100vh;
}

.sidebar {
  width: var(--sidebar-width);
  min-height: 100vh;
  background: #212529;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 100;
  padding-top: 1rem;
}

.sidebar .nav-link {
  color: rgba(255, 255, 255, 0.7);
  padding: 0.7rem 1.2rem;
  border-radius: 0;
  font-size: 0.95rem;
}

.sidebar .nav-link:hover,
.sidebar .nav-link.active {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
}

.sidebar .nav-link .badge {
  font-size: 0.7rem;
}

.sidebar-brand {
  color: #fff;
  font-size: 1.1rem;
  font-weight: 600;
  padding: 0.5rem 1.2rem 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: 0.5rem;
}

.main-content {
  margin-left: var(--sidebar-width);
  padding: 1.5rem 2rem;
}

.top-bar {
  margin-left: var(--sidebar-width);
  padding: 0.8rem 2rem;
  background: #fff;
  border-bottom: 1px solid #dee2e6;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

.stat-card {
  border-left: 4px solid;
  transition: transform 0.15s;
}

.stat-card:hover {
  transform: translateY(-2px);
}

.stat-card.primary { border-left-color: #0d6efd; }
.stat-card.warning { border-left-color: #ffc107; }
.stat-card.success { border-left-color: #198754; }
.stat-card.danger  { border-left-color: #dc3545; }
.stat-card.info    { border-left-color: #0dcaf0; }

.table th {
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  color: #6c757d;
}

.badge-status {
  font-size: 0.78rem;
  padding: 0.35em 0.65em;
}

.course-tree .module-item {
  border-left: 3px solid #0d6efd;
  margin-bottom: 0.5rem;
}

.course-tree .lesson-item {
  padding-left: 1.5rem;
}

.login-container {
  max-width: 400px;
  margin: 10vh auto;
}