/* ============================================================
   Dark Mode · Glassmorphism · Tuition QR
   ============================================================ */

:root {
  --bg-gradient: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
  --glass-bg: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.10);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.37);
  --glass-blur: blur(16px);

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent: #6366f1;
  --accent-hover: #818cf8;
  --accent-glow: rgba(99, 102, 241, 0.35);

  --danger: #ef4444;
  --success: #22c55e;
  --warning: #eab308;

  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;

  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg-gradient);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 3px; }

/* ===== Glass Card ===== */
.glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
}

.glass-sm {
  background: var(--glass-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
}

/* ===== Layout ===== */
.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px 16px;
}

.container-wide {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 16px;
}

/* ===== Header ===== */
.header {
  text-align: center;
  padding: 32px 16px 24px;
}

.header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  background: linear-gradient(135deg, #818cf8, #c084fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 4px;
}

/* ===== Search ===== */
.search-wrap {
  position: relative;
  margin-bottom: 16px;
}

.search-wrap input {
  width: 100%;
  padding: 14px 16px 14px 46px;
  background: var(--glass-bg);
  backdrop-filter: blur(8px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 1rem;
  outline: none;
  transition: border 0.2s, box-shadow 0.2s;
}

.search-wrap input::placeholder { color: var(--text-muted); }
.search-wrap input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.search-wrap .icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.2rem;
  color: var(--text-muted);
  pointer-events: none;
}

/* ===== Suggestions ===== */
.suggestions {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  z-index: 20;
  max-height: 280px;
  overflow-y: auto;
  margin-top: 4px;
  background: rgba(30, 27, 60, 0.95);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--glass-shadow);
  display: none;
}

.suggestions.open { display: block; }

.suggestions .item {
  padding: 12px 16px;
  cursor: pointer;
  transition: background 0.15s;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}

.suggestions .item:last-child { border-bottom: none; }
.suggestions .item:hover { background: rgba(99, 102, 241, 0.12); }

.suggestions .item .name { font-weight: 600; font-size: 0.95rem; }
.suggestions .item .meta { font-size: 0.78rem; color: var(--text-muted); margin-top: 2px; }
.suggestions .item mark { background: rgba(99, 102, 241, 0.3); color: var(--accent-hover); border-radius: 2px; padding: 0 2px; }

/* ===== Student Card ===== */
.student-card {
  padding: 24px;
  margin-top: 16px;
  animation: fadeUp 0.35s ease;
}

.student-card .row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid rgba(255,255,255,0.05);
}

.student-card .row:last-child { border-bottom: none; }
.student-card .label { color: var(--text-muted); font-size: 0.85rem; }
.student-card .value { font-weight: 600; font-size: 0.95rem; text-align: right; }

.student-card input[type="text"],
.student-card select {
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xs);
  color: var(--text-primary);
  padding: 8px 10px;
  font-size: 0.95rem;
  width: 160px;
  text-align: right;
  outline: none;
  transition: border 0.2s;
}

.student-card input:focus,
.student-card select:focus {
  border-color: var(--accent);
}

.student-card select option { background: #1e1b3c; color: #f1f5f9; }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.btn:active { transform: scale(0.97); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff;
  box-shadow: 0 4px 16px var(--accent-glow);
}

.btn-primary:hover { box-shadow: 0 6px 24px var(--accent-glow); transform: translateY(-1px); }

.btn-primary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  background: rgba(255,255,255,0.08);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
}

.btn-secondary:hover { background: rgba(255,255,255,0.13); }

.btn-danger {
  background: rgba(239, 68, 68, 0.15);
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.25);
}

.btn-danger:hover { background: rgba(239, 68, 68, 0.25); }

.btn-sm {
  padding: 8px 14px;
  font-size: 0.82rem;
  border-radius: var(--radius-sm);
}

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: var(--radius-sm);
}

/* ===== QR Section ===== */
.qr-section {
  margin-top: 20px;
  text-align: center;
  animation: fadeUp 0.35s ease;
}

.qr-section a {
  display: inline-block;
  text-decoration: none;
}

.qr-section a img {
  cursor: pointer;
  transition: transform 0.2s, opacity 0.3s;
}

.qr-section a:hover img {
  transform: scale(1.03);
}

.qr-section img {
  max-width: 240px;
  width: 100%;
  border-radius: var(--radius);
  background: #fff;
  padding: 8px;
  transition: opacity 0.3s;
}

.qr-section img.loading { opacity: 0.3; }

.qr-info {
  margin-top: 12px;
  padding: 16px;
  background: rgba(255,255,255,0.04);
  border-radius: var(--radius-sm);
  text-align: left;
}

.qr-info .line {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 0.88rem;
}

.qr-info .line .lbl { color: var(--text-muted); }
.qr-info .line .val { font-weight: 600; }

.transfer-content {
  margin-top: 12px;
  padding: 12px 14px;
  background: rgba(0,0,0,0.25);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255,255,255,0.06);
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  word-break: break-all;
  display: flex;
  align-items: center;
  gap: 10px;
}

.transfer-content .text { flex: 1; }

.copy-btn {
  cursor: pointer;
  background: rgba(255,255,255,0.08);
  border: none;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-xs);
  font-size: 0.8rem;
  white-space: nowrap;
  transition: 0.15s;
}

.copy-btn:hover { background: rgba(255,255,255,0.15); color: var(--text-primary); }
.copy-btn.copied { background: rgba(34,197,94,0.15); color: var(--success); }

.warning-msg {
  margin-top: 12px;
  padding: 10px 14px;
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-sm);
  color: #fca5a5;
  font-size: 0.78rem;
  text-align: center;
  line-height: 1.5;
}

/* ===== Filters (Admin) ===== */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 16px;
}

.filter-bar select,
.filter-bar input {
  padding: 10px 14px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.9rem;
  outline: none;
  flex: 1;
  min-width: 140px;
}

.filter-bar select:focus,
.filter-bar input:focus { border-color: var(--accent); }
.filter-bar select option { background: #1e1b3c; }

/* ===== Table ===== */
.table-wrap {
  overflow-x: auto;
  margin-top: 12px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

th, td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  white-space: nowrap;
}

th {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

tbody tr:hover { background: rgba(255,255,255,0.03); }

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(6px);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: fadeIn 0.2s ease;
}

.modal {
  width: 100%;
  max-width: 480px;
  padding: 28px;
  background: rgba(30, 27, 60, 0.97);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  max-height: 90vh;
  overflow-y: auto;
}

.modal h2 {
  font-size: 1.2rem;
  margin-bottom: 20px;
}

.modal .field {
  margin-bottom: 16px;
}

.modal .field label {
  display: block;
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.modal .field input,
.modal .field select {
  width: 100%;
  padding: 10px 12px;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xs);
  color: var(--text-primary);
  font-size: 0.9rem;
  outline: none;
}

.modal .field input:focus,
.modal .field select:focus { border-color: var(--accent); }
.modal .field select option { background: #1e1b3c; }

.modal .actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}

.modal .actions .btn { flex: 1; }

/* ===== Stats Grid ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 14px;
  margin-bottom: 24px;
}

.stat-card {
  padding: 20px;
  text-align: center;
}

.stat-card .num {
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(135deg, #818cf8, #c084fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-card .lbl {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ===== Admin Header ===== */
.admin-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

.admin-header h1 { font-size: 1.3rem; }

.admin-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.admin-nav .btn { font-size: 0.82rem; padding: 8px 16px; }
.admin-nav .btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ===== Tab content ===== */
.tab-content { display: none; }
.tab-content.active { display: block; animation: fadeUp 0.3s ease; }

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  padding: 12px 24px;
  border-radius: var(--radius);
  background: rgba(30, 27, 60, 0.97);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  font-size: 0.88rem;
  z-index: 200;
  opacity: 0;
  transition: all 0.35s ease;
  pointer-events: none;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
  pointer-events: auto;
}

.toast.success { border-color: rgba(34,197,94,0.4); }
.toast.error { border-color: rgba(239,68,68,0.4); }

/* ===== Skeleton / Loading ===== */
.skeleton {
  background: rgba(255,255,255,0.06);
  border-radius: var(--radius-xs);
  animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 0.7; }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ===== Empty state ===== */
.empty-state {
  text-align: center;
  padding: 48px 16px;
  color: var(--text-muted);
}

.empty-state .icon { font-size: 3rem; margin-bottom: 12px; opacity: 0.5; }

/* ===== File input ===== */
.file-upload {
  position: relative;
  padding: 24px;
  text-align: center;
  border: 2px dashed rgba(255,255,255,0.12);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border 0.2s;
}

.file-upload:hover { border-color: var(--accent); }
.file-upload input[type="file"] { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.file-upload .label { color: var(--text-muted); font-size: 0.85rem; }

/* ===== Misc ===== */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: 600;
}

.badge-green { background: rgba(34,197,94,0.15); color: var(--success); }
.badge-red { background: rgba(239,68,68,0.15); color: var(--danger); }
.badge-blue { background: rgba(99,102,241,0.15); color: var(--accent-hover); }

.checkbox-group { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px; }

.checkbox-group label {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: rgba(255,255,255,0.04);
  border-radius: var(--radius-xs);
  font-size: 0.85rem;
  cursor: pointer;
}

.checkbox-group input[type="checkbox"] { accent-color: var(--accent); }

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .container { padding: 12px; }
  .container-wide { padding: 16px 12px; }
  .header { padding: 24px 12px 16px; }
  .header h1 { font-size: 1.35rem; }
  .student-card { padding: 16px; }
  .modal { padding: 20px; }
  .admin-header { flex-direction: column; align-items: stretch; }
  .admin-nav { justify-content: center; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .filter-bar { flex-direction: column; }
  .filter-bar select,
  .filter-bar input { min-width: auto; }
  .qr-section img { max-width: 180px; }
}