:root {
  /* Red/White Theme - Light Mode */
  --primary-color: #d52b1e;
  --secondary-color: #e74c3c;
  --success-color: #27ae60;
  --danger-color: #d52b1e;
  --warning-color: #f39c12;
  --dark-bg: #ffffff;
  --card-bg: #ffffff;
  --border-color: #e0e0e0;
  --text-light: #1f2937;
  --text-muted: #6b7280;
  --hover-bg: rgba(213, 43, 30, 0.08);
  --hover-border: rgba(213, 43, 30, 0.3);
}

/* Dark Mode Colors */
body.dark-mode {
  --dark-bg: #1a1a1a;
  --card-bg: #242424;
  --border-color: #3a3a3a;
  --text-light: #f0f0f0;
  --text-muted: #b0b0b0;
  --hover-bg: rgba(213, 43, 30, 0.15);
  --hover-border: rgba(213, 43, 30, 0.4);
}

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

body {
  background-color: var(--dark-bg);
  color: var(--text-light);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  overflow-x: hidden;
  transition:
    background-color 0.3s ease,
    color 0.3s ease;
}

.dark-bg {
  background-color: var(--dark-bg);
  transition: background-color 0.3s ease;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--card-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-color);
}

/* Dark Mode Toggle — Sidebar variant */
.dark-mode-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 1rem;
  margin: 0 0.5rem 0.5rem;
  border-radius: 10px;
  background: var(--hover-bg);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.dark-mode-row:hover {
  border-color: var(--hover-border);
}

.dark-mode-row .dm-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  user-select: none;
}

.dark-mode-row .dm-label i {
  font-size: 1rem;
  color: var(--primary-color);
}

/* Toggle switch */
.dm-switch {
  position: relative;
  width: 44px;
  height: 24px;
  flex-shrink: 0;
}

.dm-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.dm-switch .slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background: var(--border-color);
  border-radius: 24px;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.dm-switch .slider::before {
  content: '';
  position: absolute;
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background: white;
  border-radius: 50%;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
}

.dm-switch input:checked + .slider {
  background: var(--primary-color);
}

.dm-switch input:checked + .slider::before {
  transform: translateX(20px);
}

/* Dark Mode Toggle — Login page floating variant */
.dark-mode-toggle-float {
  position: fixed;
  top: 1.25rem;
  right: 1.25rem;
  z-index: 10000;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  transition: all 0.3s ease;
}

.dark-mode-toggle-float:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(213, 43, 30, 0.15);
}

.dark-mode-toggle-float:active {
  transform: translateY(0) scale(0.95);
}

/* Hide old generic class if any remain */
.dark-mode-toggle {
  display: none !important;
}

/* Text Utilities */
.text-white {
  color: var(--text-light) !important;
}

.text-muted {
  color: var(--text-muted) !important;
}

.text-white-50 {
  color: rgba(31, 41, 55, 0.5) !important;
}

.text-center.text-muted.py-4 {
  background-color: #ffffff !important;
  transition: all 0.5s ease;
}

.text-link {
  color: var(--primary-color);
  text-decoration: none;
  transition: all 0.3s ease;
}

.text-link:hover {
  color: var(--primary-color);
  text-decoration: underline;
  background-color: var(--hover-bg);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
}

/* Cards */
.card {
  background-color: var(--card-bg) !important;
  border: 1px solid var(--border-color) !important;
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-2px);
  background-color: var(--hover-bg) !important;
  border-color: var(--hover-border) !important;
  box-shadow: 0 8px 16px rgba(213, 43, 30, 0.15);
}

.card-body {
  padding: 1.5rem;
}

.card-title {
  color: var(--text-light);
  font-weight: 600;
  margin-bottom: 1.5rem;
}

/* Gradient Cards */
.bg-gradient-blue {
  background: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%) !important;
}

.bg-gradient-purple {
  background: linear-gradient(135deg, #d52b1e 0%, #b91c1c 100%) !important;
}

.bg-gradient-orange {
  background: linear-gradient(135deg, #ea580c 0%, #c2410c 100%) !important;
}

.bg-gradient-green {
  background: linear-gradient(135deg, #16a34a 0%, #15803d 100%) !important;
}

/* Buttons */
.btn {
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.3s ease;
  border: none;
}

.btn-gradient {
  background: linear-gradient(
    135deg,
    var(--primary-color) 0%,
    var(--secondary-color) 100%
  );
  color: white;
  box-shadow: 0 4px 12px rgba(213, 43, 30, 0.3);
}

.btn-gradient:hover {
  transform: translateY(-2px);
  box-shadow:
    0 6px 16px rgba(213, 43, 30, 0.4),
    inset 0 0 20px rgba(255, 100, 100, 0.1);
  color: white;
}

.btn-gradient:active {
  transform: translateY(0);
}

.btn-outline-danger {
  color: var(--danger-color);
  border-color: var(--danger-color);
}

.btn-outline-danger:hover {
  background-color: var(--hover-bg);
  border-color: var(--danger-color);
  color: var(--danger-color);
  box-shadow: inset 0 0 10px rgba(213, 43, 30, 0.15);
}

.btn-outline-danger:active {
  background-color: var(--danger-color);
  color: white;
}

.btn-secondary {
  background-color: var(--border-color);
  border: 1px solid var(--border-color);
  color: var(--text-light);
  transition: all 0.3s ease;
}

.btn-secondary:hover {
  background-color: var(--hover-bg);
  border-color: var(--hover-border);
  box-shadow: inset 0 0 10px rgba(213, 43, 30, 0.1);
}

.btn-secondary:active {
  background-color: rgba(213, 43, 30, 0.2);
  border-color: var(--primary-color);
}

.btn-sm {
  padding: 0.4rem 0.8rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
}

/* Forms */
.form-control,
.form-select {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  color: var(--text-light);
  border-radius: 8px;
  transition: all 0.3s ease;
}

.form-control:hover,
.form-select:hover {
  border-color: var(--hover-border);
  background-color: var(--hover-bg);
}

.form-control:focus,
.form-select:focus {
  background-color: var(--card-bg);
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(213, 43, 30, 0.15);
  color: var(--text-light);
}

.form-control::placeholder {
  color: var(--text-muted);
}

.form-label {
  color: var(--text-light);
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.form-control-dark {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  color: var(--text-light);
}

.form-control-dark:focus {
  background-color: #ffffff;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(213, 43, 30, 0.15);
}

.form-select-dark {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  color: var(--text-light);
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
}

.form-select-dark:focus {
  background-color: #ffffff;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(213, 43, 30, 0.15);
}

/* Login Page */
.login-card {
  max-width: 450px;
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2.5rem;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
  animation: slideUp 0.6s ease-out;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.login-title {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #d52b1e 0%, #e74c3c 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.nav-link {
  color: var(--text-muted);
  border-radius: 8px;
  transition: all 0.3s ease;
  margin-bottom: 0.5rem;
}

.nav-link:hover {
  background-color: var(--hover-bg);
  color: var(--primary-color);
  box-shadow: inset 0 0 8px rgba(213, 43, 30, 0.1);
}

.nav-link.active {
  background: linear-gradient(
    135deg,
    var(--primary-color) 0%,
    var(--secondary-color) 100%
  );
  color: white !important;
  box-shadow: 0 4px 12px rgba(213, 43, 30, 0.3);
  font-weight: 600;
}

/* Sidebar */
.sidebar {
  background-color: var(--card-bg);
  border-right: 1px solid var(--border-color);
  min-height: 100vh;
  padding-top: 1rem;
  transition: all 0.3s ease;
}

.sidebar-header {
  padding: 0 1rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-header h5 {
  font-weight: 700;
  font-size: 1.25rem;
  margin: 0;
}

.sidebar-header .close-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-light);
  font-size: 1.5rem;
  cursor: pointer;
  transition: all 0.3s ease;
}

.sidebar-header .close-btn:hover {
  color: rgba(255, 100, 100, 0.8);
  transform: rotate(90deg);
}

/* Hamburger Menu Button */
.hamburger-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-light);
  font-size: 1.5rem;
  cursor: pointer;
  margin-right: 1rem;
  transition: all 0.3s ease;
  z-index: 1001;
}

.hamburger-btn:hover {
  color: rgba(255, 100, 100, 0.8);
  transform: scale(1.1);
}

.hamburger-btn i {
  transition: all 0.3s ease;
}

/* Table */
.table-dark {
  color: var(--primary-color);
  background-color: #ffffff;
}

.table-dark thead {
  border-bottom: 2px solid var(--border-color);
}

.table-dark th {
  color: var(--primary-color);
  font-weight: 600;
  border-color: var(--border-color);
  background-color: #ffffff;
}

.table-dark td {
  border-color: var(--border-color);
  vertical-align: middle;
  color: var(--primary-color);
}

.table-dark tbody tr {
  transition: all 0.2s ease;
}

.table-dark tbody tr:hover {
  background-color: rgba(213, 43, 30, 0.05);
}

#studentsTableBody {
  background-color: #ffffff !important;
  --bs-table-hover-bg: transparent !important;
}

#studentsTableBody tr {
  background-color: #ffffff !important;
}

.table-responsive {
  border-radius: 8px;
  overflow: hidden;
}

/* Alerts */
.alert {
  border-radius: 8px;
  border: 1px solid;
  animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.alert-danger {
  background-color: rgba(213, 43, 30, 0.1);
  border-color: rgba(213, 43, 30, 0.3);
  color: #b91c1c;
}

.alert-success {
  background-color: rgba(39, 174, 96, 0.1);
  border-color: rgba(39, 174, 96, 0.3);
  color: #15803d;
}

.btn-close-white {
  filter: invert(1);
}

/* Modal */
.modal-content {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
}

.modal-header,
.modal-footer {
  border-color: var(--border-color);
}

.modal-title {
  color: var(--text-light);
  font-weight: 600;
}

.modal-body {
  color: var(--text-light);
}

/* Badges */
.badge {
  border-radius: 6px;
  font-weight: 500;
  padding: 0.4rem 0.8rem;
}

.badge-primary {
  background-color: rgba(213, 43, 30, 0.2);
  color: var(--primary-color);
}

.badge-success {
  background-color: rgba(39, 174, 96, 0.2);
  color: var(--success-color);
}

/* Timeline */
.timeline {
  position: relative;
  padding: 1rem 0;
}

.timeline-item {
  padding-left: 2rem;
  position: relative;
  padding-bottom: 1.5rem;
  border-left: 2px solid var(--border-color);
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--primary-color);
  border: 2px solid var(--card-bg);
}

.timeline-item:last-child {
  border-left: none;
}

.timeline-item:last-child::after {
  display: none;
}

/* Activity Card */
.activity-card {
  background: linear-gradient(
    135deg,
    rgba(213, 43, 30, 0.1) 0%,
    rgba(214, 88, 48, 0.1) 100%
  );
  border: 1px solid rgba(213, 43, 30, 0.2);
  border-radius: 12px;
  padding: 1.5rem;
  transition: all 0.3s ease;
  cursor: pointer;
}

.activity-card:hover {
  transform: translateY(-4px);
  border-color: rgba(213, 43, 30, 0.4);
  box-shadow: 0 8px 16px rgba(213, 43, 30, 0.12);
  background: linear-gradient(
    135deg,
    rgba(255, 100, 100, 0.08) 0%,
    rgba(255, 100, 100, 0.05) 100%
  );
}

.activity-card h5 {
  color: var(--primary-color);
  font-weight: 600;
}

.activity-card p {
  color: var(--text-muted);
  margin: 0.5rem 0;
  font-size: 0.95rem;
}

/* Rankings */
.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  font-weight: 700;
  font-size: 1rem;
}

.rank-1 {
  background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
  color: white;
}

.rank-2 {
  background: linear-gradient(135deg, #e5e7eb 0%, #d1d5db 100%);
  color: #1f2937;
}

.rank-3 {
  background: linear-gradient(135deg, #fed7aa 0%, #fdba74 100%);
  color: #1f2937;
}

.rank-default {
  background: rgba(0, 212, 255, 0.1);
  color: var(--primary-color);
}

/* Responsive */
@media (max-width: 768px) {
  .hamburger-btn {
    display: block;
  }

  .sidebar {
    position: fixed;
    left: -100%;
    width: 70%;
    max-width: 300px;
    height: 100vh;
    z-index: 1000;
    transition: left 0.3s ease;
    overflow-y: auto;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.5);
  }

  .sidebar.show {
    left: 0;
  }

  .sidebar-header .close-btn {
    display: block;
  }

  .container-fluid > .row {
    position: relative;
  }

  .col-md-9,
  .col-lg-10 {
    width: 100% !important;
    margin-left: 0;
  }

  main {
    padding: 1rem !important;
    margin-top: 3rem;
  }

  .login-card {
    margin: 1rem;
    padding: 1.5rem;
  }

  .card {
    margin-bottom: 1rem;
  }

  .table {
    font-size: 0.85rem;
  }

  .row {
    margin-bottom: 1rem;
  }

  .col-md-4,
  .col-md-3 {
    margin-bottom: 1rem;
  }

  .navbar-top {
    top: 0;
    left: 0;
    right: 0;
    height: 3rem;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    z-index: 999;
    padding: 0 1rem;
  }
}

@media (max-width: 576px) {
  .login-title {
    font-size: 2rem;
  }

  .btn-group {
    flex-direction: column;
  }

  .btn-group .btn {
    border-radius: 8px;
    margin-bottom: 0.5rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .card-body {
    padding: 1rem;
  }

  .table {
    font-size: 0.75rem;
  }
}

/* Loading Animation */
.loading {
  display: inline-block;
  width: 1rem;
  height: 1rem;
  border: 2px solid rgba(0, 212, 255, 0.3);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Utilities */
.min-vh-100 {
  min-height: 100vh;
}

.opacity-75 {
  opacity: 0.75;
}

.border-secondary {
  border-color: var(--border-color) !important;
}

.bg-secondary {
  background-color: var(--border-color) !important;
}

.position-sticky {
  position: sticky;
}

.overflow-hidden {
  overflow: hidden !important;
}

/* Print Styles */
@media print {
  .sidebar,
  .btn-outline-danger,
  .btn-gradient {
    display: none;
  }

  body {
    background-color: white;
  }

  .card,
  .table {
    break-inside: avoid;
  }
}