/* ============================================
   ATTENDANCE MONITORING SYSTEM - STYLES
   ============================================ */

/* CSS Variables */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #1a1a24;
  --bg-card-hover: #22222e;
  --text-primary: #f0f0f5;
  --text-secondary: #8888a0;
  --text-muted: #555566;
  --accent-primary: #10b981;
  --accent-secondary: #3b82f6;
  --danger: #ef4444;
  --warning: #f59e0b;
  --success: #10b981;
  --border-color: #2a2a3a;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s ease;
}

/* Light Theme */
.light-theme {
  --bg-primary: #f5f5f7;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f0f0f5;
  --text-primary: #1a1a2e;
  --text-secondary: #555566;
  --text-muted: #888899;
  --border-color: #e0e0e8;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
}

/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
}

/* ============================================
   UTILITIES
   ============================================ */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px;
}

.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-4 {
  gap: 16px;
}

.gap-6 {
  gap: 24px;
}

.grid {
  display: grid;
}

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

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

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

.hidden {
  display: none !important;
}

/* ============================================
   LOGIN PAGE
   ============================================ */
.login-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--bg-primary) 0%, #1a1a2e 100%);
  padding: 20px;
}

.login-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 48px;
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow);
}

.login-logo {
  text-align: center;
  margin-bottom: 32px;
}

.login-logo h1 {
  font-size: 28px;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 8px;
}

.login-logo p {
  color: var(--text-secondary);
  font-size: 14px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 14px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 15px;
  transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 24px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  width: 100%;
  background: var(--accent-primary);
  color: #fff;
}

.btn-primary:hover {
  background: #0ea572;
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
}

.btn-danger:hover {
  background: #dc2626;
}

.login-demo {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

.login-demo h3 {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.demo-credentials {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.demo-user {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  font-size: 13px;
}

.demo-user span {
  color: var(--text-secondary);
}

.demo-user code {
  color: var(--accent-primary);
  font-family: 'Monaco', 'Consolas', monospace;
}

.error-message {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: var(--danger);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
  font-size: 14px;
}

/* ============================================
   DASHBOARD LAYOUT
   ============================================ */
.dashboard {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.dashboard-header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 24px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent-primary);
}

.header-badge {
  padding: 4px 12px;
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-primary);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 14px;
  color: #fff;
}

.user-name {
  font-weight: 500;
  font-size: 14px;
}

.theme-toggle {
  width: 40px;
  height: 40px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-primary);
}

.theme-toggle:hover {
  background: var(--bg-card-hover);
}

.dashboard-main {
  flex: 1;
  padding: 24px;
}

.dashboard-content {
  max-width: 1400px;
  margin: 0 auto;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
}

.page-subtitle {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 24px;
  transition: var(--transition);
}

.card:hover {
  border-color: var(--accent-primary);
  box-shadow: 0 0 20px rgba(16, 185, 129, 0.1);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.card-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Stat Cards */
.stat-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 24px;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--card-accent, var(--accent-primary));
}

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

.stat-card.success { --card-accent: var(--success); }
.stat-card.warning { --card-accent: var(--warning); }
.stat-card.danger { --card-accent: var(--danger); }
.stat-card.info { --card-accent: var(--accent-secondary); }

.stat-icon {
  width: 48px;
  height: 48px;
  background: rgba(16, 185, 129, 0.1);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  font-size: 24px;
}

.stat-card.success .stat-icon { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.stat-card.warning .stat-icon { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.stat-card.danger .stat-icon { background: rgba(239, 68, 68, 0.1); color: var(--danger); }
.stat-card.info .stat-icon { background: rgba(59, 130, 246, 0.1); color: var(--accent-secondary); }

.stat-value {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 14px;
  color: var(--text-secondary);
}

.stat-change {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  margin-top: 8px;
  padding: 4px 8px;
  border-radius: 4px;
}

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

.stat-change.negative {
  background: rgba(239, 68, 68, 0.1);
  color: var(--danger);
}

/* ============================================
   TABLES
   ============================================ */
.table-container {
  overflow-x: auto;
}

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

thead {
  background: var(--bg-secondary);
}

th {
  padding: 14px 16px;
  text-align: left;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border-color);
  cursor: pointer;
  transition: var(--transition);
}

th:hover {
  color: var(--text-primary);
}

th.sortable::after {
  content: '↕';
  margin-left: 8px;
  opacity: 0.5;
}

th.sort-asc::after {
  content: '↑';
  opacity: 1;
  color: var(--accent-primary);
}

th.sort-desc::after {
  content: '↓';
  opacity: 1;
  color: var(--accent-primary);
}

td {
  padding: 16px;
  border-bottom: 1px solid var(--border-color);
  font-size: 14px;
}

tr:hover {
  background: var(--bg-card-hover);
}

/* Attendance Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
}

.badge-success {
  background: rgba(16, 185, 129, 0.15);
  color: var(--success);
}

.badge-warning {
  background: rgba(245, 158, 11, 0.15);
  color: var(--warning);
}

.badge-danger {
  background: rgba(239, 68, 68, 0.15);
  color: var(--danger);
}

/* Progress Bar */
.progress-bar {
  height: 8px;
  background: var(--bg-secondary);
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.5s ease;
}

.progress-fill.success { background: var(--success); }
.progress-fill.warning { background: var(--warning); }
.progress-fill.danger { background: var(--danger); }

/* ============================================
   CHARTS
   ============================================ */
.chart-container {
  position: relative;
  height: 250px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.pie-chart {
  position: relative;
  width: 200px;
  height: 200px;
}

.pie-chart-center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  background: var(--bg-card);
  width: 100px;
  height: 100px;
  border-radius: 50%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.pie-chart-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent-primary);
}

.pie-chart-label {
  font-size: 11px;
  color: var(--text-secondary);
}

.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 20px;
  justify-content: center;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
}

.legend-color {
  width: 12px;
  height: 12px;
  border-radius: 3px;
}

/* Bar Chart */
.bar-chart {
  display: flex;
  align-items: flex-end;
  justify-content: space-around;
  height: 200px;
  padding: 20px 0;
  gap: 12px;
}

.bar-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
  max-width: 60px;
}

.bar {
  width: 100%;
  background: linear-gradient(180deg, var(--accent-primary) 0%, rgba(16, 185, 129, 0.5) 100%);
  border-radius: 4px 4px 0 0;
  transition: height 0.5s ease;
  min-height: 4px;
}

.bar-label {
  margin-top: 8px;
  font-size: 11px;
  color: var(--text-secondary);
}

.bar-value {
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

/* ============================================
   FILTERS & SEARCH
   ============================================ */
.filters-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.search-box {
  flex: 1;
  min-width: 250px;
  position: relative;
}

.search-box input {
  width: 100%;
  padding: 12px 16px 12px 44px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  transition: var(--transition);
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent-primary);
}

.search-box::before {
  content: '🔍';
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 14px;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.filter-group label {
  font-size: 13px;
  color: var(--text-secondary);
}

.filter-group select {
  padding: 10px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: var(--transition);
}

.filter-group select:focus {
  outline: none;
  border-color: var(--accent-primary);
}

/* Filter Tabs */
.filter-tabs {
  display: flex;
  gap: 8px;
  background: var(--bg-secondary);
  padding: 4px;
  border-radius: var(--radius-sm);
}

.filter-tab {
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
}

.filter-tab:hover {
  color: var(--text-primary);
}

.filter-tab.active {
  background: var(--accent-primary);
  color: #fff;
}

/* ============================================
   INSIGHTS PANEL
   ============================================ */
.insights-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

.insight-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 20px;
}

.insight-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.insight-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

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

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

.insight-icon.danger {
  background: rgba(239, 68, 68, 0.1);
  color: var(--danger);
}

.insight-title {
  font-size: 14px;
  font-weight: 600;
}

.insight-list {
  list-style: none;
}

.insight-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
}

.insight-item:last-child {
  border-bottom: none;
}

.insight-item-name {
  font-size: 13px;
  color: var(--text-primary);
}

.insight-item-value {
  font-size: 13px;
  font-weight: 600;
}

/* ============================================
   STUDENT PROFILE
   ============================================ */
.student-profile {
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.profile-avatar {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  font-weight: 700;
  color: #fff;
}

.profile-info h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 4px;
}

.profile-meta {
  display: flex;
  gap: 20px;
  color: var(--text-secondary);
  font-size: 14px;
}

.profile-meta span {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ============================================
   SUBJECT CARDS
   ============================================ */
.subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.subject-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 20px;
  transition: var(--transition);
}

.subject-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.subject-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.subject-name {
  font-size: 16px;
  font-weight: 600;
}

.subject-code {
  font-size: 12px;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 4px 8px;
  border-radius: 4px;
}

.subject-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.subject-stat {
  text-align: center;
}

.subject-stat-value {
  font-size: 18px;
  font-weight: 700;
}

.subject-stat-label {
  font-size: 11px;
  color: var(--text-secondary);
}

/* ============================================
   ALERTS
   ============================================ */
.alert {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}

.alert-warning {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.alert-danger {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.alert-icon {
  font-size: 20px;
}

.alert-content h4 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 4px;
}

.alert-content p {
  font-size: 13px;
  color: var(--text-secondary);
}

/* ============================================
   TABS
   ============================================ */
.tabs {
  display: flex;
  gap: 4px;
  background: var(--bg-secondary);
  padding: 4px;
  border-radius: var(--radius-sm);
  margin-bottom: 24px;
}

.tab {
  flex: 1;
  padding: 12px 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.tab:hover {
  color: var(--text-primary);
}

.tab.active {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* ============================================
   DEPARTMENT SELECTOR
   ============================================ */
.dept-selector {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.dept-btn {
  padding: 12px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.dept-btn:hover {
  border-color: var(--accent-primary);
  color: var(--text-primary);
}

.dept-btn.active {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: #fff;
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1200px) {
  .stat-cards {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .insights-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .stat-cards {
    grid-template-columns: 1fr;
  }
  
  .header-content {
    flex-wrap: wrap;
    gap: 16px;
  }
  
  .filters-bar {
    flex-direction: column;
    align-items: stretch;
  }
  
  .search-box {
    min-width: 100%;
  }
  
  .student-profile {
    flex-direction: column;
    text-align: center;
  }
  
  .profile-meta {
    flex-direction: column;
    gap: 8px;
  }
  
  .login-card {
    padding: 32px 24px;
  }
  
  .page-title {
    font-size: 22px;
  }
}

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

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-10px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.animate-fade-in {
  animation: fadeIn 0.4s ease forwards;
}

.animate-slide-in {
  animation: slideIn 0.3s ease forwards;
}

/* Staggered animation delays */
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }
.stagger-4 { animation-delay: 0.4s; }