/* ─── VARIABLES ──────────────────────────────────────────────── */
:root {
  --primary:       #0097b2;
  --primary-dark:  #007a90;
  --primary-light: #e0f7fa;
  --black:         #111111;
  --white:         #ffffff;
  --bg:            #f0f2f5;
  --surface:       #ffffff;
  --text:          #111111;
  --text-muted:    #6b7280;
  --border:        #e2e8f0;
  --danger:        #e53e3e;
  --danger-light:  #fff5f5;
  --success:       #38a169;
  --radius:        8px;
  --radius-lg:     12px;
  --shadow-sm:     0 1px 3px rgba(0,0,0,.08);
  --shadow:        0 4px 12px rgba(0,0,0,.10);
  --nav-h:         60px;
  --transition:    .18s ease;
}

/* ─── RESET ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 15px; }
body {
  font-family: 'Inter', 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); text-decoration: underline; }
img { max-width: 100%; }

/* ─── TOP NAV ─────────────────────────────────────────────────── */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: var(--black);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  box-shadow: var(--shadow);
}
.navbar-brand {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: .5px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.navbar-brand img { height: 32px; }
.navbar-links {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
}
.navbar-links a {
  color: rgba(255,255,255,.8);
  padding: 6px 12px;
  border-radius: var(--radius);
  font-size: .875rem;
  transition: background var(--transition), color var(--transition);
}
.navbar-links a:hover, .navbar-links a.active {
  background: rgba(255,255,255,.1);
  color: var(--white);
  text-decoration: none;
}
.navbar-user {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: .875rem;
  color: rgba(255,255,255,.7);
}
.navbar-user strong { color: var(--white); }

/* ─── PAGE WRAPPER ────────────────────────────────────────────── */
.page-wrapper {
  max-width: 1200px;
  margin: 0 auto;
  padding: 28px 20px;
}

/* ─── PAGE HEADER ─────────────────────────────────────────────── */
.page-header {
  margin-bottom: 24px;
}
.page-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--black);
}
.page-header p { color: var(--text-muted); margin-top: 2px; }
.page-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

/* ─── STAT CARDS ──────────────────────────────────────────────── */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
  margin-bottom: 28px;
}
.stat-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--primary);
}
.stat-card .stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--black);
  line-height: 1;
}
.stat-card .stat-label {
  font-size: .8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-top: 6px;
}

/* ─── CARD / SECTION ──────────────────────────────────────────── */
.card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
  overflow: hidden;
}
.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
}
.card-header h2 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--black);
}
.card-body { padding: 24px; }

/* ─── TABLE ───────────────────────────────────────────────────── */
.table-responsive { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: .9rem;
}
thead tr {
  background: var(--black);
  color: var(--white);
}
thead th {
  padding: 11px 16px;
  text-align: left;
  font-weight: 600;
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .4px;
  white-space: nowrap;
}
tbody tr {
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}
tbody tr:hover { background: var(--primary-light); }
tbody td {
  padding: 12px 16px;
  vertical-align: middle;
}
tbody tr:last-child { border-bottom: none; }

/* ─── BUTTONS ─────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-size: .875rem;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: background var(--transition), transform var(--transition), opacity var(--transition);
  text-decoration: none;
  white-space: nowrap;
}
.btn:hover { opacity: .9; transform: translateY(-1px); text-decoration: none; }
.btn:active { transform: translateY(0); }

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

.btn-dark { background: var(--black); color: var(--white); }
.btn-dark:hover { background: #333; color: var(--white); }

.btn-danger { background: var(--danger); color: var(--white); }
.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}
.btn-outline:hover { background: var(--primary-light); color: var(--primary); }

.btn-sm { padding: 5px 10px; font-size: .8rem; }
.btn-icon { padding: 6px 8px; }

/* ─── FORMS ───────────────────────────────────────────────────── */
.form-group { margin-bottom: 18px; }
.form-group label {
  display: block;
  font-size: .875rem;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--black);
}
.form-group label .required { color: var(--danger); }
.form-control {
  width: 100%;
  padding: 9px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  font-size: .9rem;
  color: var(--text);
  background: var(--white);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
}
.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0,151,178,.15);
}
textarea.form-control { resize: vertical; min-height: 90px; }
select.form-control { cursor: pointer; }

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  align-items: end;
}
.form-inline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}
.form-inline .form-control { width: auto; flex: 1; min-width: 140px; }

/* ─── ALERT / ERROR ───────────────────────────────────────────── */
.alert {
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: .875rem;
  margin-bottom: 16px;
}
.alert-error {
  background: var(--danger-light);
  color: var(--danger);
  border: 1px solid #feb2b2;
}
.alert-success {
  background: #f0fff4;
  color: var(--success);
  border: 1px solid #9ae6b4;
}

/* ─── BADGE ───────────────────────────────────────────────────── */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .3px;
}
.badge-primary { background: var(--primary-light); color: var(--primary-dark); }
.badge-success { background: #f0fff4; color: var(--success); }
.badge-danger  { background: var(--danger-light); color: var(--danger); }
.badge-open    { background: #f0fff4; color: var(--success); }
.badge-closed  { background: #f7fafc; color: var(--text-muted); }

/* ─── SIGN IN PAGE ────────────────────────────────────────────── */
.auth-wrapper {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--black);
  padding: 20px;
}
.auth-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 40px 36px;
  width: 100%;
  max-width: 400px;
  box-shadow: var(--shadow);
}
.auth-logo {
  text-align: center;
  margin-bottom: 28px;
}
.auth-logo img { height: 48px; }
.auth-logo h1 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary);
  margin-top: 10px;
}
.auth-card h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 22px;
  color: var(--black);
}
.auth-footer {
  text-align: center;
  margin-top: 18px;
  font-size: .85rem;
  color: var(--text-muted);
}

/* ─── RFID REGISTRATION ───────────────────────────────────────── */
.rfid-card {
  background: var(--primary-light);
  border: 2px dashed var(--primary);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  margin: 20px 0;
}
.rfid-card h3 { color: var(--primary-dark); margin-bottom: 8px; }
.uid-display {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--black);
  letter-spacing: 2px;
  margin: 16px 0;
  font-family: monospace;
}
.scanning-pulse {
  display: inline-block;
  width: 12px; height: 12px;
  background: var(--primary);
  border-radius: 50%;
  animation: pulse 1.2s ease-in-out infinite;
  margin-right: 8px;
  vertical-align: middle;
}
@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50%       { transform: scale(1.4); opacity: .5; }
}

/* ─── ATTENDANCE DASHBOARD ────────────────────────────────────── */
.live-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: .8rem;
  color: var(--success);
  font-weight: 600;
}
.live-dot {
  width: 8px; height: 8px;
  background: var(--success);
  border-radius: 50%;
  animation: pulse 1.5s ease-in-out infinite;
}

/* ─── TEACHER SCHEDULE ROW ────────────────────────────────────── */
.teacher-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.teacher-row:last-child { border-bottom: none; }
.teacher-row label { font-weight: 500; flex: 1; min-width: 160px; }

/* ─── EMPTY STATE ─────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  color: var(--text-muted);
}
.empty-state i { font-size: 2.5rem; margin-bottom: 12px; color: var(--border); }
.empty-state p { margin-bottom: 16px; }

/* ─── BACK LINK ───────────────────────────────────────────────── */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: .875rem;
  margin-bottom: 20px;
}
.back-link:hover { color: var(--primary); text-decoration: none; }

/* ─── UTILITIES ───────────────────────────────────────────────── */
.text-muted  { color: var(--text-muted); }
.text-primary { color: var(--primary); }
.text-danger  { color: var(--danger); }
.fw-bold { font-weight: 700; }
.mb-0 { margin-bottom: 0; }
.gap-2 { gap: 8px; }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.flex-wrap { flex-wrap: wrap; }

/* ─── RESPONSIVE ──────────────────────────────────────────────── */
@media (max-width: 640px) {
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .page-header-row { flex-direction: column; align-items: flex-start; gap: 12px; }
  .navbar { padding: 0 16px; }
  .auth-card { padding: 28px 20px; }
  .card-body { padding: 16px; }
  thead th, tbody td { padding: 9px 10px; }
}