:root {
  --primary: #3498db;
  --primary-dark: #2980b9;
  --secondary: #2c3e50;
  --success: #27ae60;
  --danger: #e74c3c;
  --warning: #f39c12;
  --info: #1abc9c;
  --light: #f8f9fa;
  --dark: #343a40;
  --gray: #95a5a6;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f5f7fa;
  color: #333;
  line-height: 1.6;
  overflow-x: hidden;
}

/* Main Container */
.main-container {
  display: flex;
  min-height: 100vh;
}

/* Sidebar Styles */
.sidebar {
  background: var(--secondary);
  color: white;
  width: 250px;
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  transition: all 0.3s;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-content {
  overflow-y: auto;
  flex: 1;
  padding-bottom: 20px;
  scrollbar-width: thin;
  scrollbar-color: var(--primary) var(--secondary);
}

/* Scrollbar styling */
.sidebar-content::-webkit-scrollbar {
  width: 6px;
}

.sidebar-content::-webkit-scrollbar-track {
  background: var(--secondary);
}

.sidebar-content::-webkit-scrollbar-thumb {
  background-color: var(--primary);
  border-radius: 3px;
}

.sidebar-header {
  padding: 20px;
  text-align: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  flex-shrink: 0;
}

.profile-section {
  padding: 20px;
  text-align: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  flex-shrink: 0;
}

.profile-img {
  width: 70px;
  height: 70px;
  object-fit: cover;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.2);
  margin-bottom: 10px;
}

.nav {
  padding: 10px;
  flex-grow: 1;
}

.nav-link {
  color: rgba(255, 255, 255, 0.8);
  padding: 12px 15px;
  margin: 5px 0;
  border-radius: 4px;
  display: flex;
  align-items: center;
  transition: all 0.3s;
  text-decoration: none;
}

.nav-link:hover, .nav-link.active {
  background: var(--primary);
  color: white;
}

.nav-link i {
  margin-right: 10px;
  width: 20px;
  text-align: center;
}

/* Main Content */
.main-content {
  flex: 1;
  margin-left: 250px;
  padding: 20px;
  min-height: 100vh;
  transition: all 0.3s;
  overflow-y: auto;
}

/* Mobile Styles */
.mobile-menu-toggle {
  position: fixed;
  top: 15px;
  left: 15px;
  z-index: 1100;
  background: var(--secondary);
  color: white;
  border: none;
  border-radius: 4px;
  padding: 8px 10px;
  cursor: pointer;
  display: none;
}

.sidebar-close {
  position: absolute;
  top: 10px;
  right: 10px;
  background: none;
  border: none;
  color: white;
  font-size: 1.3rem;
  cursor: pointer;
  display: none;
  z-index: 1101;
}

.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  display: none;
}

@media (max-width: 991px) {
  .sidebar {
    left: -250px;
  }

  .sidebar.open {
    left: 0;
  }

  .main-content {
    margin-left: 0;
  }

  .mobile-menu-toggle {
    display: block;
  }

  .sidebar-close {
    display: block;
  }

  .sidebar.open + .sidebar-overlay {
    display: block;
  }
}

/* Search Input Styling */
#tableSearch {
  max-width: 300px;
  margin: auto;
  margin-bottom: 15px;
  border-radius: 20px;
  padding: 8px 15px;
}

/* Table Styling */
.table-dark {
  background-color: var(--secondary);
}

.table-dark th {
  background-color: var(--secondary);
  border-color: rgba(255, 255, 255, 0.1);
  color: white;
}

/* Button Styling */
.btn-outline-primary {
  border-color: var(--primary);
  color: var(--primary);
}

.btn-outline-primary:hover {
  background-color: var(--primary);
  border-color: var(--primary);
  color: white;
}

/* Card Styling */
.card {
  border: none;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.card-header {
  background-color: var(--primary);
  color: white;
  border-radius: 8px 8px 0 0 !important;
  border-bottom: none;
}

/* Badge Styling */
.badge {
  border-radius: 20px;
}

/* Modal Styling */
.modal-content {
  border-radius: 8px;
  border: none;
}

.modal-header {
  border-radius: 8px 8px 0 0;
}

/* Form Styling */
.form-control {
  border-radius: 6px;
  border: 1px solid #ddd;
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
}

/* Pagination Styling */
.page-link {
  color: var(--primary);
  border-color: var(--primary);
}

.page-link:hover {
  color: white;
  background-color: var(--primary);
  border-color: var(--primary);
}

.page-item.active .page-link {
  background-color: var(--primary);
  border-color: var(--primary);
}

/* Alert Styling */
.alert {
  border-radius: 8px;
  border: none;
}

/* Loading Spinner */
.spinner-border {
  color: var(--primary);
}

/* Responsive Design */
@media (max-width: 768px) {
  .main-content {
    padding: 15px;
  }

  .sidebar {
    width: 250px;
  }

  .main-content {
    margin-left: 0;
  }
}

/* Custom Scrollbar for Main Content */
.main-content::-webkit-scrollbar {
  width: 6px;
}

.main-content::-webkit-scrollbar-track {
  background: #f1f1f1;
}

.main-content::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 3px;
}

.main-content::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* Ensure Bootstrap modals appear above the fixed sidebar which uses a high z-index */
.modal-backdrop {
  z-index: 1240 !important;
}
.modal {
  z-index: 1250 !important;
}

/* Teacher Profile Styles */
.teacher-profile-header {
    background: linear-gradient(135deg, #3498db 0%, #2c3e50 100%);
    color: white;
    border-radius: 10px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    margin-bottom: 2rem;
}
.teacher-avatar {
    width: 150px;
    height: 150px;
    object-fit: cover;
    border: 5px solid white;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}
.stat-card {
    border-radius: 10px;
    transition: all 0.3s ease;
    border: none;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-bottom: 1.5rem;
}
.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}
.stat-card .card-body {
    padding: 1.5rem;
}
.rating-stars {
    color: #f39c12;
    font-size: 1.2rem;
    letter-spacing: 2px;
}
.nav-pills .nav-link {
    border-radius: 5px;
    margin-right: 5px;
    padding: 10px 15px;
    font-weight: 500;
  color: white;
    background-color: #3498db;
    border: 1px solid #dee2e6;
}
.nav-pills .nav-link:hover {
    background-color: #e9ecef;
}
.nav-pills .nav-link.active {
    background-color: #3498db;
    color: white;
    border-color: #3498db;
    box-shadow: 0 2px 5px rgba(52, 152, 219, 0.5);
}
.tab-content {
    background-color: white;
    border-radius: 0 0 10px 10px;
    padding: 2rem;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    border: 1px solid #eee;
    border-top: none;
}
.info-table th {
    background-color: #f8f9fa;
    font-weight: 600;
    white-space: nowrap;
}
.attendance-badge {
    font-size: 0.75rem;
    padding: 0.35em 0.65em;
}
.progress {
    height: 10px;
    border-radius: 5px;
}
.session-card, .assignment-card {
    transition: all 0.3s ease;
    margin-bottom: 1rem;
    border-left: 4px solid #3498db;
}
.session-card:hover, .assignment-card:hover {
    transform: translateX(5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}
.rating-card {
    border-left: 4px solid #f39c12;
}
.course-badge {
    background-color: #e3f2fd;
    color: #1976d2;
}
.group-badge {
    background-color: #e8f5e9;
    color: #388e3c;
}
.attendance-stats {
    font-size: 0.85rem;
}
.submission-stats {
    font-size: 0.85rem;
}

/* Footer Styles */
.site-footer {
    background-color: var(--secondary);
    color: white;
    padding: 40px 0 20px;
    position: relative;
    width: calc(100% - 250px);
    margin-left: 250px;
    z-index: 10;
    margin-top: 60px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 30px;
}

.footer-column {
    flex: 1;
    min-width: 250px;
    margin-bottom: 20px;
}

.footer-column h3 {
    color: var(--primary);
    margin-bottom: 15px;
    font-size: 1.2rem;
    font-weight: 600;
}

.footer-column p {
    line-height: 1.6;
    margin-bottom: 15px;
    color: rgba(255, 255, 255, 0.8);
}

.footer-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-column ul li {
    margin-bottom: 8px;
}

.footer-column ul li a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
}

.footer-column ul li a:hover {
    color: var(--primary);
}

.footer-column ul li a i {
    margin-right: 8px;
    font-size: 0.8rem;
}

.social-icons {
    display: flex;
    gap: 15px;
    margin-top: 15px;
}

.social-icons a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.2rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    text-decoration: none;
}

.social-icons a:hover {
    color: white;
    background-color: var(--primary);
    transform: translateY(-2px);
}

/* Footer Responsive */
@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .footer-column {
        margin-bottom: 30px;
    }

    .social-icons {
        justify-content: center;
    }
}