/* ============================================
   Tap & GO - College Bus Attendance System
   Modern UI/UX Styles
   ============================================ */

:root {
  --primary: #4f46e5;
  --primary-light: #6366f1;
  --primary-dark: #4338ca;
  --secondary: #06b6d4;
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-2: linear-gradient(135deg, #4f46e5 0%, #06b6d4 100%);
  --gradient-3: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 50%, #06b6d4 100%);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius-sm: 6px;
  --radius: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--gray-100);
  min-height: 100vh;
  color: var(--gray-800);
  line-height: 1.6;
}

/* ============================================
   Sidebar Navigation
   ============================================ */

.app-layout {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 280px;
  background: var(--gray-900);
  color: white;
  position: fixed;
  height: 100vh;
  overflow-y: auto;
  z-index: 100;
  transition: transform 0.3s ease;
}

.sidebar-header {
  padding: 1.5rem;
  background: var(--gradient-2);
  text-align: center;
}

.sidebar-logo {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 0.25rem;
}

.sidebar-subtitle {
  font-size: 0.75rem;
  opacity: 0.8;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.sidebar-nav {
  padding: 1rem 0;
}

.nav-section {
  padding: 0 1rem;
  margin-bottom: 0.5rem;
}

.nav-section-title {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gray-500);
  padding: 0.75rem 1rem;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.875rem 1rem;
  margin: 0.25rem 0.75rem;
  border-radius: var(--radius);
  color: var(--gray-300);
  text-decoration: none;
  transition: all 0.2s ease;
  font-size: 0.9rem;
}

.nav-item:hover {
  background: rgba(255, 255, 255, 0.1);
  color: white;
}

.nav-item.active {
  background: var(--primary);
  color: white;
}

.nav-item-icon {
  font-size: 1.25rem;
  width: 24px;
  text-align: center;
}

/* ============================================
   Main Content
   ============================================ */

.main-content {
  flex: 1;
  margin-left: 280px;
  min-height: 100vh;
}

.top-bar {
  background: white;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 50;
}

.page-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--gray-800);
}

.breadcrumb {
  font-size: 0.875rem;
  color: var(--gray-500);
}

.content-area {
  padding: 2rem;
}

/* ============================================
   Cards & Containers
   ============================================ */

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
}

.card {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: all 0.3s ease;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-800);
}

.card-body {
  padding: 1.5rem;
}

.card-footer {
  padding: 1rem 1.5rem;
  background: var(--gray-50);
  border-top: 1px solid var(--gray-200);
}

/* ============================================
   Stats Cards
   ============================================ */

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: white;
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.stat-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
}

.stat-icon.primary { background: rgba(79, 70, 229, 0.1); color: var(--primary); }
.stat-icon.success { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.stat-icon.warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.stat-icon.secondary { background: rgba(6, 182, 212, 0.1); color: var(--secondary); }

.stat-info h3 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--gray-800);
  line-height: 1.2;
}

.stat-info p {
  font-size: 0.875rem;
  color: var(--gray-500);
}

/* ============================================
   Form Elements
   ============================================ */

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--gray-700);
}

.form-label .required {
  color: var(--error);
  margin-left: 2px;
}

.form-input,
.form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-family: inherit;
  transition: all 0.2s ease;
  background: white;
}

.form-input:focus,
.form-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-input::placeholder {
  color: var(--gray-400);
}

.form-input.error {
  border-color: var(--error);
}

.form-hint {
  font-size: 0.75rem;
  color: var(--gray-500);
  margin-top: 0.25rem;
}

.form-error {
  font-size: 0.75rem;
  color: var(--error);
  margin-top: 0.25rem;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--gray-200);
  color: var(--gray-700);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--gray-300);
}

.btn-success {
  background: var(--success);
  color: white;
}

.btn-success:hover:not(:disabled) {
  background: #059669;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--gray-300);
  color: var(--gray-700);
}

.btn-outline:hover:not(:disabled) {
  border-color: var(--primary);
  color: var(--primary);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

.btn-block {
  width: 100%;
}

.btn-icon {
  padding: 0.75rem;
  border-radius: var(--radius);
}

/* ============================================
   Step Indicator (Registration Flow)
   ============================================ */

.steps-container {
  display: flex;
  justify-content: center;
  margin-bottom: 2rem;
}

.steps {
  display: flex;
  align-items: center;
  gap: 0;
}

.step {
  display: flex;
  align-items: center;
}

.step-circle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gray-200);
  color: var(--gray-500);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  transition: all 0.3s ease;
}

.step.active .step-circle {
  background: var(--primary);
  color: white;
  box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.2);
}

.step.completed .step-circle {
  background: var(--success);
  color: white;
}

.step-line {
  width: 60px;
  height: 3px;
  background: var(--gray-200);
  margin: 0 0.5rem;
  transition: background 0.3s ease;
}

.step.completed + .step .step-line,
.step.completed .step-line {
  background: var(--success);
}

.step-label {
  position: absolute;
  top: 50px;
  font-size: 0.75rem;
  color: var(--gray-500);
  white-space: nowrap;
  transform: translateX(-50%);
  left: 50%;
}

.step.active .step-label {
  color: var(--primary);
  font-weight: 600;
}

/* ============================================
   Camera / Face Training Section
   ============================================ */

.camera-section {
  background: var(--gray-900);
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  aspect-ratio: 4/3;
  max-width: 500px;
  margin: 0 auto;
}

.camera-preview {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.camera-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.5rem;
  pointer-events: none;
}

.camera-instruction {
  background: rgba(0, 0, 0, 0.7);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-align: center;
  align-self: center;
  backdrop-filter: blur(10px);
}

.camera-controls {
  display: flex;
  justify-content: center;
  gap: 1rem;
  pointer-events: auto;
}

.camera-btn {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  border: 4px solid white;
  background: var(--primary);
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.camera-btn:hover {
  transform: scale(1.1);
  background: var(--primary-light);
}

/* Face Grid Preview */
.face-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  margin-top: 1rem;
}

.face-preview {
  aspect-ratio: 1;
  border-radius: var(--radius);
  background: var(--gray-200);
  overflow: hidden;
  position: relative;
}

.face-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.face-preview.empty {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gray-400);
  font-size: 1.5rem;
}

.face-preview .check {
  position: absolute;
  bottom: 4px;
  right: 4px;
  width: 20px;
  height: 20px;
  background: var(--success);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 0.75rem;
}

/* Progress Bar */
.progress-container {
  margin: 1rem 0;
}

.progress-bar {
  height: 8px;
  background: var(--gray-200);
  border-radius: 999px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-2);
  border-radius: 999px;
  transition: width 0.5s ease;
}

.progress-text {
  text-align: center;
  font-size: 0.875rem;
  color: var(--gray-600);
  margin-top: 0.5rem;
}

/* ============================================
   Alerts & Notifications
   ============================================ */

.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  margin-bottom: 1rem;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.alert-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
}

.alert-content {
  flex: 1;
}

.alert-title {
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.alert-message {
  font-size: 0.875rem;
  opacity: 0.9;
}

.alert-success {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
  color: #065f46;
}

.alert-error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: #991b1b;
}

.alert-warning {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.2);
  color: #92400e;
}

.alert-info {
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.2);
  color: #155e75;
}

/* ============================================
   Tables
   ============================================ */

.table-container {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 1rem;
  text-align: left;
}

th {
  background: var(--gray-50);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--gray-600);
  border-bottom: 2px solid var(--gray-200);
}

td {
  border-bottom: 1px solid var(--gray-200);
  font-size: 0.9rem;
}

tr:hover {
  background: var(--gray-50);
}

.table-actions {
  display: flex;
  gap: 0.5rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
}

.badge-success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--success);
}

.badge-warning {
  background: rgba(245, 158, 11, 0.1);
  color: var(--warning);
}

.badge-error {
  background: rgba(239, 68, 68, 0.1);
  color: var(--error);
}

/* ============================================
   Loading States
   ============================================ */

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid var(--gray-200);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.spinner-sm {
  width: 16px;
  height: 16px;
  border-width: 2px;
}

.spinner-lg {
  width: 40px;
  height: 40px;
  border-width: 4px;
}

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

.skeleton {
  background: linear-gradient(90deg, var(--gray-200) 25%, var(--gray-100) 50%, var(--gray-200) 75%);
  background-size: 200% 100%;
  animation: skeleton 1.5s infinite;
  border-radius: var(--radius);
}

@keyframes skeleton {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.9);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
}

.loading-text {
  margin-top: 1rem;
  font-weight: 600;
  color: var(--gray-600);
}

/* ============================================
   Success Screen
   ============================================ */

.success-screen {
  text-align: center;
  padding: 3rem 2rem;
}

.success-icon {
  width: 100px;
  height: 100px;
  background: rgba(16, 185, 129, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 3rem;
  color: var(--success);
  animation: scaleIn 0.5s ease;
}

@keyframes scaleIn {
  0% { transform: scale(0); }
  50% { transform: scale(1.2); }
  100% { transform: scale(1); }
}

.success-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--gray-800);
  margin-bottom: 0.5rem;
}

.success-message {
  color: var(--gray-600);
  margin-bottom: 2rem;
}

.qr-display {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  border: 2px solid var(--gray-200);
  display: inline-block;
  margin-bottom: 1.5rem;
}

.qr-display img {
  width: 200px;
  height: 200px;
}

/* ============================================
   Empty States
   ============================================ */

.empty-state {
  text-align: center;
  padding: 3rem 2rem;
  color: var(--gray-500);
}

.empty-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 0.5rem;
}

.empty-message {
  margin-bottom: 1.5rem;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

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

  .mobile-toggle {
    display: block;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .top-bar {
    padding: 1rem;
  }

  .content-area {
    padding: 1rem;
  }
}

/* ============================================
   Animations
   ============================================ */

.fade-in {
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.slide-in {
  animation: slideIn 0.4s ease;
}

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

/* ============================================
   Utility Classes
   ============================================ */

.hidden { display: none !important; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.w-full { width: 100%; }