:root {
  --bg-primary: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent-gold: #f59e0b;
  --accent-blue: #3b82f6;
  --accent-green: #10b981;
  --accent-red: #ef4444;
  --border-color: #334155;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body {
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: var(--font-family);
  line-height: 1.6;
  padding: 24px;
  min-height: 100vh;
}

.container {
  max-width: 1300px;
  margin: 0 auto;
}

/* Header & Brand */
.header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 28px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 16px;
}

.brand-title {
  font-size: 26px;
  font-weight: 700;
  background: linear-gradient(135deg, #f59e0b, #eab308);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: #000;
}
.btn-primary:hover {
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
}

.btn-secondary {
  background: #334155;
  color: #f8fafc;
}
.btn-secondary:hover {
  background: #475569;
}

.btn-whatsapp {
  background: #25D366;
  color: #fff;
  padding: 6px 12px;
  font-size: 12px;
}
.btn-whatsapp:hover {
  background: #1da851;
}

.btn-renew {
  background: #3b82f6;
  color: #fff;
  padding: 6px 12px;
  font-size: 12px;
}
.btn-renew:hover {
  background: #2563eb;
}

.btn-icon {
  padding: 6px 10px;
  font-size: 13px;
}

.btn-danger {
  background: rgba(239, 68, 68, 0.2);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.4);
}
.btn-danger:hover {
  background: #ef4444;
  color: #fff;
}

/* Stats Row */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-bottom: 28px;
}

.stat-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s;
}
.stat-card:hover {
  transform: translateY(-2px);
}

.stat-info h3 {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}
.stat-info p {
  font-size: 28px;
  font-weight: 700;
  margin-top: 4px;
}

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}

.stat-expiring .stat-icon {
  background: rgba(245, 158, 11, 0.15);
  color: var(--accent-gold);
}
.stat-expiring {
  border-left: 4px solid var(--accent-gold);
}

.stat-expired .stat-icon {
  background: rgba(239, 68, 68, 0.15);
  color: var(--accent-red);
}
.stat-expired {
  border-left: 4px solid var(--accent-red);
}

.stat-active .stat-icon {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-green);
}
.stat-active {
  border-left: 4px solid var(--accent-green);
}

.stat-revenue .stat-icon {
  background: rgba(59, 130, 246, 0.15);
  color: var(--accent-blue);
}
.stat-revenue {
  border-left: 4px solid var(--accent-blue);
}

/* Controls & Toolbar */
.toolbar {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 16px 20px;
  margin-bottom: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
}

.filter-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.tab-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.tab-btn.active {
  background: var(--accent-gold);
  color: #000;
  font-weight: 600;
  border-color: var(--accent-gold);
}

.search-box {
  position: relative;
  min-width: 280px;
}
.search-input {
  width: 100%;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 8px 14px 8px 36px;
  border-radius: 8px;
  font-size: 14px;
}
.search-input:focus {
  outline: none;
  border-color: var(--accent-gold);
}
.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
}

/* Table Design */
.table-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

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

.student-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 14px;
}

.student-table th {
  background: #111827;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-color);
}

.student-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-color);
  vertical-align: middle;
}

.student-table tbody tr {
  transition: background 0.15s;
}
.student-table tbody tr:hover {
  background-color: var(--bg-card-hover);
}

/* Status Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
}

.badge-active {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-expiring {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.4);
  animation: pulse-border 2s infinite;
}

.badge-expired {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.4);
}

@keyframes pulse-border {
  0% { box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.4); }
  70% { box-shadow: 0 0 0 6px rgba(245, 158, 11, 0); }
  100% { box-shadow: 0 0 0 0 rgba(245, 158, 11, 0); }
}

.seat-pill {
  background: #334155;
  color: #e2e8f0;
  padding: 3px 10px;
  border-radius: 6px;
  font-weight: 700;
  font-size: 13px;
}

.action-buttons {
  display: flex;
  gap: 6px;
}

/* Seat Grid Visualizer */
.seat-visualizer-card {
  margin-top: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
}
.seat-visualizer-header {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.seat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
  gap: 10px;
}

.seat-box {
  background: #0f172a;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 10px 4px;
  text-align: center;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
}
.seat-box:hover {
  transform: scale(1.05);
}

.seat-box.occupied-active {
  background: rgba(16, 185, 129, 0.2);
  border-color: #10b981;
  color: #34d399;
}
.seat-box.occupied-expiring {
  background: rgba(245, 158, 11, 0.25);
  border-color: #f59e0b;
  color: #fbbf24;
}
.seat-box.occupied-expired {
  background: rgba(239, 68, 68, 0.25);
  border-color: #ef4444;
  color: #f87171;
}

/* Modal Popup */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  z-index: 999;
  justify-content: center;
  align-items: center;
  padding: 16px;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  width: 100%;
  max-width: 500px;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.5);
  overflow: hidden;
  animation: fadeIn 0.2s ease-out;
}

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

.modal-header {
  padding: 16px 20px;
  background: #111827;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.modal-header h3 {
  font-size: 17px;
  font-weight: 700;
}
.modal-close {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 20px;
  cursor: pointer;
}

.modal-body {
  padding: 20px;
}

.form-group {
  margin-bottom: 16px;
}
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-muted);
}
.form-control {
  width: 100%;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 14px;
}
.form-control:focus {
  outline: none;
  border-color: var(--accent-gold);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.modal-footer {
  padding: 14px 20px;
  background: #111827;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-muted);
}

/* Branding Footer */
.app-footer {
  margin-top: 40px;
  padding: 20px 0;
  text-align: center;
  border-top: 1px solid var(--border-color);
  font-size: 13px;
  color: var(--text-muted);
}

.app-footer a {
  color: var(--accent-gold);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.2s ease;
}

.app-footer a:hover {
  color: #fbbf24;
  text-decoration: underline;
}