/* ========================================================================
   Term Schedule Builder — Design System & Styles
   Clean white/light theme with horizontal timeline table layout
   ======================================================================== */

/* ── Reset ──────────────────────────────────────────────────────────────── */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ── Design Tokens ──────────────────────────────────────────────────────── */
:root {
  /* Backgrounds */
  --bg-base: #f5f7fa;
  --bg-surface: #ffffff;
  --bg-elevated: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: rgba(0, 0, 0, 0.02);
  --bg-input: #f0f2f5;
  --bg-input-focus: #e8ecf1;
  --bg-overlay: rgba(0, 0, 0, 0.4);

  /* Borders */
  --border: #e2e5ea;
  --border-light: #d0d5dd;
  --border-focus: rgba(59, 130, 246, 0.5);

  /* Text */
  --text-primary: #1a1d26;
  --text-secondary: #5a6070;
  --text-muted: #98a1b3;

  /* Type accent colors — Lectures (#95B3D7) */
  --lecture-accent: #366092;
  --lecture-bg: #95b3d7;
  --lecture-text: #0f2537;
  --lecture-border: #366092;

  /* Type accent colors — Labs & Tutorials (#DA9694) */
  --lab-accent: #9c4543;
  --lab-bg: #da9694;
  --lab-text: #3b1413;
  --lab-border: #9c4543;

  /* Type accent colors — Tutorials (#DA9694) */
  --tutorial-accent: #9c4543;
  --tutorial-bg: #da9694;
  --tutorial-text: #3b1413;
  --tutorial-border: #9c4543;

  /* Program colors */
  --prog-general: #607d8b;
  --prog-general-bg: rgba(96, 125, 139, 0.1);
  --prog-biotech: #2e7d32;
  --prog-biotech-bg: rgba(46, 125, 50, 0.1);
  --prog-chemistry: #f57f17;
  --prog-chemistry-bg: rgba(245, 127, 23, 0.1);
  --prog-renewable: #1565c0;
  --prog-renewable-bg: rgba(21, 101, 192, 0.1);
  --prog-physics: #7b1fa2;
  --prog-physics-bg: rgba(123, 31, 162, 0.1);
  --prog-math: #00695c;
  --prog-math-bg: rgba(0, 105, 92, 0.1);

  /* General accents */
  --accent-blue: #3b82f6;
  --accent-red: #ef4444;
  --accent-green: #10b981;
  --accent-amber: #f59e0b;
  --accent-purple: #8b5cf6;

  /* Radius */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;

  /* Font */
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.1);
  --shadow-xl: 0 16px 48px rgba(0,0,0,0.12);

  /* Transitions */
  --t-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --t-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --t-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Base ───────────────────────────────────────────────────────────────── */
html {
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font);
  background: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── App Container ──────────────────────────────────────────────────────── */
.app {
  max-width: 1800px;
  margin: 0 auto;
  padding: 0 20px 40px;
}

/* ── Header ─────────────────────────────────────────────────────────────── */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-left h1 {
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.header-left .logo-icon {
  font-size: 1.6rem;
}

.header-center {
  font-size: 0.76rem;
  color: var(--text-muted);
  font-weight: 600;
  text-align: center;
  padding: 5px 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.header-badge {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 8px;
  border-radius: 20px;
  background: rgba(74, 144, 244, 0.12);
  color: var(--accent-blue);
  border: 1px solid rgba(74, 144, 244, 0.2);
}

.header-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* ── Buttons ────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  background: var(--bg-card);
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--t-fast);
  white-space: nowrap;
}

.btn:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.18);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn:active { transform: translateY(0); }

.btn * {
  pointer-events: none;
}

.header, .header-actions, .btn {
  pointer-events: auto !important;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-blue) 0%, #3a7ae0 100%);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 2px 8px rgba(74, 144, 244, 0.25);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #5a9ef7 0%, #4a8af0 100%);
  box-shadow: 0 4px 16px rgba(74, 144, 244, 0.35);
  border-color: transparent;
}

.btn-danger {
  color: var(--accent-red);
  border-color: rgba(239, 85, 101, 0.25);
}

.btn-danger:hover {
  background: rgba(239, 85, 101, 0.1);
  border-color: rgba(239, 85, 101, 0.4);
}

.btn-success {
  background: linear-gradient(135deg, var(--accent-green) 0%, #22c388 100%);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 2px 8px rgba(52, 211, 153, 0.25);
}

.btn-success:hover {
  box-shadow: 0 4px 16px rgba(52, 211, 153, 0.35);
  border-color: transparent;
}

.btn-emerald {
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 2px 8px rgba(5, 150, 105, 0.25);
}

.btn-emerald:hover {
  background: linear-gradient(135deg, #047857 0%, #065f46 100%);
  box-shadow: 0 4px 16px rgba(5, 150, 105, 0.35);
  border-color: transparent;
}

.btn-icon {
  padding: 8px;
  min-width: 36px;
  justify-content: center;
  font-size: 1.1rem;
}

.btn-sm {
  padding: 5px 10px;
  font-size: 0.75rem;
}

/* ── Stats Bar ──────────────────────────────────────────────────────────── */
.stats-bar {
  display: flex;
  gap: 12px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.stat-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  backdrop-filter: blur(8px);
  flex: 1;
  min-width: 130px;
}

.stat-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
}

.stat-icon.blue { background: rgba(74, 144, 244, 0.12); }
.stat-icon.red { background: rgba(239, 85, 101, 0.12); }
.stat-icon.amber { background: rgba(240, 160, 48, 0.12); }
.stat-icon.green { background: rgba(52, 211, 153, 0.12); }
.stat-icon.purple { background: rgba(167, 139, 250, 0.12); }

.stat-info { display: flex; flex-direction: column; }

.stat-value {
  font-size: 1.2rem;
  font-weight: 800;
  line-height: 1.2;
}

.stat-label {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.legend-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 16px;
  padding: 10px 16px;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  flex-wrap: wrap;
}

.legend-left {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.legend-credit {
  font-size: 0.76rem;
  color: var(--text-muted);
  font-weight: 600;
  margin-left: auto;
}

.legend-section {
  display: flex;
  align-items: center;
  gap: 14px;
}

.legend-section-title {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-right: 2px;
}

.legend-divider {
  width: 1px;
  height: 24px;
  background: var(--border-light);
  margin: 0 6px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 3px;
}

.legend-dot.lecture { background: #95b3d7; border: 1px solid #366092; }
.legend-dot.lab { background: #da9694; border: 1px solid #9c4543; }
.legend-dot.tutorial { background: #da9694; border: 1px solid #9c4543; }

/* ══════════════════════════════════════════════════════════════════════════
   SCHEDULE TABLE — Horizontal timeline layout
   ══════════════════════════════════════════════════════════════════════════ */

.schedule-container {
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  border: 1px solid var(--border);
  overflow: hidden;
  contain: paint;
  backdrop-filter: blur(12px);
}

.schedule-scroll {
  overflow-x: auto;
  overflow-y: auto;
  max-height: calc(100vh - 260px);
  border-radius: var(--radius-lg);
}

/* Custom scrollbar */
.schedule-scroll::-webkit-scrollbar { width: 8px; height: 8px; }
.schedule-scroll::-webkit-scrollbar-track { background: #f0f2f5; }
.schedule-scroll::-webkit-scrollbar-thumb { background: #c5cad3; border-radius: 4px; }
.schedule-scroll::-webkit-scrollbar-thumb:hover { background: #a0a8b5; }

/* Table */
.sched-table {
  border-collapse: separate;
  border-spacing: 0;
  width: max-content;
  min-width: 100%;
}

/* ── Table Header ─────────────────────────────────────────────────────── */
.sched-table thead th {
  position: sticky;
  top: 0;
  z-index: 20;
  background: #d9d9d9 !important;
  border-bottom: 2px solid #000000 !important;
  color: #1a1d26 !important;
  font-weight: 800;
  white-space: nowrap;
}

.sched-th-day {
  min-width: 80px;
  width: 80px;
  padding: 8px 10px;
  text-align: center;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-right: 2px solid #000000 !important;
  border-bottom: 2px solid #000000 !important;
  position: sticky;
  left: 0;
  z-index: 25 !important;
  background: #d9d9d9 !important;
  color: #1a1d26 !important;
  border-top-left-radius: calc(var(--radius-lg) - 1px);
}

.sched-table thead tr th:last-child,
.sched-th-end {
  border-top-right-radius: calc(var(--radius-lg) - 1px);
}

.sched-table tbody tr:last-child td:first-child,
.sched-table tbody tr:last-child td.sched-day {
  border-bottom-left-radius: calc(var(--radius-lg) - 1px);
}

.sched-table tbody tr:last-child td:last-child,
.sched-table tbody tr:last-child td.sched-end-cell {
  border-bottom-right-radius: calc(var(--radius-lg) - 1px);
}

.sched-th-level {
  min-width: 90px;
  width: 90px;
  padding: 8px 8px;
  text-align: center;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-right: 2px solid #000000 !important;
  border-bottom: 2px solid #000000 !important;
  position: sticky;
  left: 80px;
  z-index: 24 !important;
  background: #d9d9d9 !important;
  color: #1a1d26 !important;
}

.sched-th-time {
  min-width: 58px;
  width: 58px;
  padding: 8px 2px;
  text-align: center;
  font-size: 0.68rem;
  font-weight: 700;
  color: #1a1d26;
  border-right: 1px solid #000000 !important;
  border-bottom: 2px solid #000000 !important;
  white-space: nowrap;
  background: #d9d9d9 !important;
}

.sched-th-time.on-hour {
  border-right: 2px solid #000000 !important;
  color: #000000;
  font-weight: 800;
  background: #d9d9d9 !important;
}

.sched-th-end {
  min-width: 58px;
  width: 58px;
  border-right: none;
  border-bottom: 2px solid #000000 !important;
  font-size: 0.68rem;
  font-weight: 800;
  color: #000000;
  background: #d9d9d9 !important;
}

.sched-end-cell {
  width: 58px;
  min-width: 58px;
  border-right: none;
  border-bottom: 2px solid #000000 !important;
  background: transparent;
}

/* ── Table Body ───────────────────────────────────────────────────────── */

/* Day cell */
.sched-day {
  position: sticky;
  left: 0;
  z-index: 20;
  font-weight: 800;
  font-size: 0.78rem;
  padding: 6px 10px;
  text-align: center;
  border-right: 2px solid #000000 !important;
  border-bottom: 3px solid #000000 !important;
  vertical-align: middle;
  letter-spacing: -0.01em;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  min-height: 50px;
  min-width: 80px;
  width: 80px;
}

/* Level cell */
.sched-level {
  position: sticky;
  left: 80px;
  z-index: 15;
  background: #ffffff !important;
  font-weight: 700;
  font-size: 0.7rem;
  padding: 4px 6px;
  text-align: center;
  border-right: 2px solid #000000 !important;
  border-bottom: 1.5px solid #000000 !important;
  vertical-align: middle;
  white-space: nowrap;
  min-width: 90px;
  width: 90px;
  box-shadow: 3px 0 6px -2px rgba(0, 0, 0, 0.08);
}

.sched-level-pill {
  display: inline-block;
  padding: 3px 10px;
  border-radius: var(--radius-xs);
  font-weight: 800;
  font-size: 0.68rem;
  letter-spacing: 0.01em;
}

/* Empty cell */
.sched-empty {
  border-right: 1px solid #000000 !important;
  border-bottom: 1.5px solid #000000 !important;
  height: 50px;
}

.sched-empty.on-hour {
  border-right: 2px solid #000000 !important;
}

/* ── Entry Cell (course block) ─────────────────────────────────────────── */
.sched-entry-cell {
  padding: 4px 8px;
  cursor: pointer;
  vertical-align: middle;
  border-left: 4px solid;
  border-top: 1.5px solid rgba(0, 0, 0, 0.15);
  border-bottom: 1.5px solid rgba(0, 0, 0, 0.15);
  border-right: 1.5px solid rgba(0, 0, 0, 0.15);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  transition: all var(--t-fast);
  height: 52px;
  position: relative;
  text-align: center;
  border-radius: 2px;
}

.sched-entry-cell:hover {
  filter: brightness(0.95);
  z-index: 5;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.12);
}

/* Conflict cell indicator */
.sched-entry-cell.has-conflict {
  border: 2px solid #ef4444 !important;
  background: rgba(239, 68, 68, 0.16) !important;
  box-shadow: 0 0 8px rgba(239, 68, 68, 0.35) !important;
}

.entry-conflict-badge {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  font-size: 0.58rem;
  font-weight: 800;
  color: #ffffff;
  background: #dc2626;
  padding: 1px 5px;
  border-radius: 3px;
  letter-spacing: 0.02em;
  line-height: 1.2;
  margin-bottom: 2px;
  box-shadow: 0 1px 3px rgba(220, 38, 38, 0.3);
  animation: pulseWarning 2s infinite;
}

@keyframes pulseWarning {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.75; }
}

.popup-conflict-box {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.popup-conflict-title {
  font-size: 0.78rem;
  font-weight: 800;
  color: #dc2626;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.popup-conflict-list {
  font-size: 0.72rem;
  color: #7f1d1d;
  padding-left: 16px;
  margin: 0;
}

.popup-conflict-list li {
  margin-bottom: 2px;
  font-weight: 600;
}

.sched-entry-cell-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  width: 100%;
  height: 100%;
  gap: 1px;
}

/* Lecture entries */
.sched-entry-cell.lecture {
  background: var(--lecture-bg);
  border-left-color: var(--lecture-accent);
  border-top-color: rgba(29, 78, 216, 0.35);
  border-bottom-color: rgba(29, 78, 216, 0.35);
  border-right-color: rgba(29, 78, 216, 0.35);
}

/* Lab entries */
.sched-entry-cell.lab {
  background: var(--lab-bg);
  border-left-color: var(--lab-accent);
  border-top-color: rgba(220, 38, 38, 0.35);
  border-bottom-color: rgba(220, 38, 38, 0.35);
  border-right-color: rgba(220, 38, 38, 0.35);
}

/* Tutorial entries */
.sched-entry-cell.tutorial {
  background: var(--tutorial-bg);
  border-left-color: var(--tutorial-accent);
  border-top-color: rgba(217, 119, 6, 0.35);
  border-bottom-color: rgba(217, 119, 6, 0.35);
  border-right-color: rgba(217, 119, 6, 0.35);
}

/* Entry content inside cell */
.entry-course {
  font-size: 0.72rem;
  font-weight: 800;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  text-align: center;
  width: 100%;
}

.sched-entry-cell.lecture .entry-course { color: var(--lecture-text); }
.sched-entry-cell.lab .entry-course { color: var(--lab-text); }
.sched-entry-cell.tutorial .entry-course { color: var(--tutorial-text); }

.entry-type-label {
  font-size: 0.63rem;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  text-align: center;
  width: 100%;
}

.sched-entry-cell.lecture .entry-type-label { color: var(--lecture-accent); }
.sched-entry-cell.lab .entry-type-label { color: var(--lab-accent); }
.sched-entry-cell.tutorial .entry-type-label { color: var(--tutorial-accent); }

/* Color details across all entry types (Lecture, Lab, Tutorial) */
.sched-entry-cell .entry-course .code-part {
  color: #0000ff !important;
  font-weight: 800;
}
.sched-entry-cell .entry-course .name-part {
  color: #000000 !important;
  font-weight: 800;
}
.sched-entry-cell .entry-type-label .type-prefix {
  color: #0000ff !important;
  font-weight: 800;
}
.sched-entry-cell .entry-type-label .type-group {
  color: #ff0000 !important;
  font-weight: 800;
}
.sched-entry-cell .entry-instructor,
.sched-entry-cell .entry-facility {
  color: #000000 !important;
  font-weight: 700;
}

.entry-instructor {
  font-size: 0.65rem;
  font-weight: 700;
  color: #1e293b;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  text-align: center;
  width: 100%;
}

.entry-facility {
  font-size: 0.62rem;
  font-weight: 700;
  color: #334155;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  text-align: center;
  width: 100%;
}

/* ── Row separators ───────────────────────────────────────────────────── */
.sched-row td {
  border-bottom: 1.5px solid #000000 !important;
}

.sched-row.level-last td {
  border-bottom: 5.5px solid #000000 !important;
}

.sched-row.day-last td,
.sched-day {
  border-bottom: 3.5px solid #dc2626 !important;
}

/* ── Empty state ──────────────────────────────────────────────────────── */
.sched-empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-muted);
}

.sched-empty-state .icon { font-size: 2.5rem; margin-bottom: 10px; opacity: 0.4; }
.sched-empty-state .title { font-size: 0.95rem; font-weight: 700; margin-bottom: 4px; }
.sched-empty-state .sub { font-size: 0.8rem; }

/* ══════════════════════════════════════════════════════════════════════════
   MODALS
   ══════════════════════════════════════════════════════════════════════════ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg-overlay);
  backdrop-filter: blur(6px);
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  animation: fadeIn 200ms ease;
}

.modal-overlay.active { display: flex; }

.modal {
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 620px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  animation: slideUp 250ms ease;
}

.modal::-webkit-scrollbar { width: 6px; }
.modal::-webkit-scrollbar-track { background: transparent; }
.modal::-webkit-scrollbar-thumb { background: #d0d5dd; border-radius: 3px; }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg-elevated);
  z-index: 5;
}

.modal-header h2 {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.3rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-xs);
  transition: all var(--t-fast);
  line-height: 1;
}

.modal-close:hover {
  color: var(--text-primary);
  background: rgba(0,0,0,0.05);
}

.modal-body { padding: 24px; }

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 24px;
  border-top: 1px solid var(--border);
}

/* ── Form ───────────────────────────────────────────────────────────────── */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.form-group.full-width { grid-column: 1 / -1; }

.form-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.instructors-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.instructor-input-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.instructor-num-badge {
  font-size: 0.7rem;
  font-weight: 800;
  color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.25);
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.btn-remove-inst {
  background: none;
  border: 1px solid #fca5a5;
  color: #ef4444;
  font-size: 1.1rem;
  font-weight: 800;
  cursor: pointer;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--t-fast);
  line-height: 1;
  flex-shrink: 0;
}

.btn-remove-inst:hover {
  background: #fee2e2;
  color: #dc2626;
  border-color: #f87171;
}

.form-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.form-input,
.form-select {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  background: var(--bg-input);
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 500;
  transition: all var(--t-fast);
  outline: none;
}

.form-input:focus,
.form-select:focus {
  border-color: var(--border-focus);
  background: var(--bg-input-focus);
  box-shadow: 0 0 0 3px rgba(74, 144, 244, 0.1);
}

.form-input::placeholder { color: var(--text-muted); }

.form-select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%238b90a7' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 30px;
}

.form-select option {
  background: var(--bg-elevated);
  color: var(--text-primary);
}

.component-preview {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  background: rgba(74, 144, 244, 0.08);
  border: 1px solid rgba(74, 144, 244, 0.15);
  font-size: 0.8rem;
}

.component-preview .code {
  font-weight: 800;
  color: var(--accent-blue);
  font-family: 'Courier New', monospace;
}

.component-preview .label {
  color: var(--text-secondary);
  font-weight: 500;
}

/* ── Type Selector ──────────────────────────────────────────────────────── */
.type-selector {
  display: flex;
  gap: 8px;
}

.type-option {
  flex: 1;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-light);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 0.8rem;
  font-weight: 700;
  cursor: pointer;
  text-align: center;
  transition: all var(--t-fast);
}

.type-option:hover {
  border-color: rgba(255,255,255,0.18);
  color: var(--text-primary);
}

.type-option.active.lecture-type {
  background: var(--lecture-bg);
  border-color: var(--lecture-accent);
  color: var(--lecture-text);
}

.type-option.active.lab-type {
  background: var(--lab-bg);
  border-color: var(--lab-accent);
  color: var(--lab-text);
}

.type-option.active.tutorial-type {
  background: var(--tutorial-bg);
  border-color: var(--tutorial-accent);
  color: var(--tutorial-text);
}

/* ── Sub-group selector ─────────────────────────────────────────────────── */
.sub-group-selector {
  display: flex;
  gap: 6px;
}

.sub-group-btn {
  flex: 1;
  padding: 8px;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-light);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
  text-align: center;
  transition: all var(--t-fast);
}

.sub-group-btn.active {
  background: rgba(74, 144, 244, 0.12);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* ── Dropzone ───────────────────────────────────────────────────────────── */
.dropzone {
  border: 2px dashed var(--border-light);
  border-radius: var(--radius-md);
  padding: 40px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--t-normal);
  margin-bottom: 16px;
}

.dropzone:hover,
.dropzone.drag-over {
  border-color: var(--accent-blue);
  background: rgba(74, 144, 244, 0.04);
}

.dropzone-icon { font-size: 2.5rem; margin-bottom: 10px; }
.dropzone-title { font-weight: 700; font-size: 0.95rem; margin-bottom: 4px; }
.dropzone-sub { font-size: 0.78rem; color: var(--text-muted); }
.dropzone input[type="file"] { display: none; }

/* ── Import Preview ─────────────────────────────────────────────────────── */
.import-preview { margin-top: 16px; }

.import-preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.import-preview-header h3 { font-size: 0.9rem; font-weight: 700; }

.import-preview-count {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
  background: rgba(52, 211, 153, 0.1);
  padding: 3px 10px;
  border-radius: 20px;
}

.import-table-wrap {
  max-height: 250px;
  overflow-y: auto;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.import-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.72rem;
}

.import-table th {
  padding: 8px 10px;
  text-align: left;
  font-weight: 700;
  color: var(--text-secondary);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 0.66rem;
}

.import-table td {
  padding: 6px 10px;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
  white-space: nowrap;
}

.import-table tr:hover td { background: rgba(255,255,255,0.02); }

/* ── Entry Detail Popup ─────────────────────────────────────────────────── */
.entry-popup {
  position: fixed;
  z-index: 2000;
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 18px;
  min-width: 280px;
  max-width: 340px;
  max-height: calc(100vh - 30px);
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  animation: fadeIn 150ms ease;
}

.entry-popup::-webkit-scrollbar { width: 5px; }
.entry-popup::-webkit-scrollbar-track { background: transparent; }
.entry-popup::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }

.entry-popup-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 12px;
  gap: 10px;
}

.entry-popup-course {
  font-size: 0.95rem;
  font-weight: 800;
}

.entry-popup-type {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 4px;
  white-space: nowrap;
}

.entry-popup-type.lecture { background: var(--lecture-bg); color: var(--lecture-text); }
.entry-popup-type.lab { background: var(--lab-bg); color: var(--lab-text); }
.entry-popup-type.tutorial { background: var(--tutorial-bg); color: var(--tutorial-text); }

.entry-popup-details {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 14px;
}

.entry-popup-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
}

.entry-popup-row .icon { width: 16px; text-align: center; font-size: 0.85rem; }
.entry-popup-row .label { color: var(--text-muted); min-width: 65px; }
.entry-popup-row .value { color: var(--text-primary); font-weight: 600; }

.entry-popup-actions {
  display: flex;
  gap: 8px;
  border-top: 1px solid var(--border);
  padding-top: 12px;
}

/* ── Toast ──────────────────────────────────────────────────────────────── */
.app.page-locked {
  filter: blur(4px) grayscale(20%);
  transition: filter 0.3s ease;
}

.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 5000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  color: var(--text-primary);
  font-size: 0.82rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  animation: slideInRight 250ms ease;
  min-width: 250px;
}

.toast.success { border-left: 3px solid var(--accent-green); }
.toast.error { border-left: 3px solid var(--accent-red); }
.toast.info { border-left: 3px solid var(--accent-blue); }
.toast.hiding { animation: slideOutRight 250ms ease forwards; }

/* ── Footer ─────────────────────────────────────────────────────────────── */
.credit {
  text-align: center;
  padding: 24px 0 8px;
  font-size: 0.76rem;
  color: var(--text-muted);
  font-weight: 500;
}

.credit strong { color: var(--text-secondary); font-weight: 700; }

/* ── Confirm Dialog ─────────────────────────────────────────────────────── */
.confirm-content { text-align: center; padding: 10px 0; }
.confirm-content .warn-icon { font-size: 2.5rem; margin-bottom: 12px; }
.confirm-content p { font-size: 0.88rem; color: var(--text-secondary); margin-bottom: 6px; }
.confirm-content .warn-msg { font-weight: 700; color: var(--text-primary); }

/* ── Animations ─────────────────────────────────────────────────────────── */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes slideInRight { from { opacity: 0; transform: translateX(40px); } to { opacity: 1; transform: translateX(0); } }
@keyframes slideOutRight { from { opacity: 1; transform: translateX(0); } to { opacity: 0; transform: translateX(40px); } }

/* ── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .header { flex-direction: column; align-items: flex-start; }
  .header-actions { width: 100%; }
  .form-grid { grid-template-columns: 1fr; }
  .stats-bar { flex-wrap: wrap; }
  .stat-card { flex: 1 1 calc(50% - 6px); min-width: 0; }
  .legend-bar { flex-wrap: wrap; gap: 10px; }
  .type-selector { flex-direction: column; }
}

/* ── Unscheduled & Special Entries Panel ─────────────────────────────── */
.unscheduled-section-container {
  margin-top: 24px;
  background: #ffffff;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  padding: 18px 20px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
}

.unscheduled-header {
  margin-bottom: 14px;
}

.unscheduled-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1rem;
  font-weight: 800;
  color: #1e293b;
}

.unscheduled-badge {
  background: #3b82f6;
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 12px;
}

.unscheduled-sub {
  font-size: 0.78rem;
  color: #64748b;
  margin-top: 2px;
  display: block;
}

.unscheduled-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}

.unscheduled-card {
  border-radius: 8px;
  padding: 12px 14px;
  border-left: 4px solid #3b82f6;
  background: #f8fafc;
  border-top: 1px solid #e2e8f0;
  border-right: 1px solid #e2e8f0;
  border-bottom: 1px solid #e2e8f0;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.unscheduled-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.unscheduled-card.lec-card {
  background: #eff6ff;
  border-left-color: #3b82f6;
}

.unscheduled-card.lab-card {
  background: #fef2f2;
  border-left-color: #ef4444;
}

.unscheduled-card.tut-card {
  background: #fff7ed;
  border-left-color: #f97316;
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 4px;
}

.card-code {
  font-weight: 800;
  font-size: 0.88rem;
  color: #0f172a;
}

.card-type-tag {
  font-size: 0.65rem;
  font-weight: 800;
  padding: 2px 6px;
  border-radius: 4px;
}

.card-type-tag.lecture { background: #dbeafe; color: #1e40af; }
.card-type-tag.lab { background: #fee2e2; color: #991b1b; }
.card-type-tag.tutorial { background: #ffedd5; color: #9a3412; }

.card-name {
  font-size: 0.78rem;
  color: #334155;
  margin-bottom: 6px;
  font-weight: 600;
}

.card-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.72rem;
  color: #64748b;
  margin-top: 3px;
}

.card-class-no, .card-notes {
  font-size: 0.7rem;
  color: #475569;
  margin-top: 4px;
  background: rgba(255, 255, 255, 0.6);
  padding: 2px 6px;
  border-radius: 4px;
}

@media (max-width: 480px) {
  html { font-size: 13px; }
  .app { padding: 0 10px 20px; }
  .stat-card { flex: 1 1 100%; }
  .modal { max-height: 95vh; border-radius: var(--radius-md); }
  .modal-body { padding: 16px; }
}

/* ── Utility ────────────────────────────────────────────────────────────── */
.hidden { display: none !important; }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ══════════════════════════════════════════════════════════════════════════
   DUPLICATE MODAL & SESSION CLONING STYLES
   ══════════════════════════════════════════════════════════════════════════ */
.duplicate-source-card {
  background: #f8fafc;
  border: 1.5px solid #cbd5e1;
  border-left: 4px solid var(--accent-blue);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
}

.dup-source-top {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
  flex-wrap: wrap;
}

.dup-source-code {
  font-size: 0.95rem;
  font-weight: 800;
  color: #1e3a8a;
  background: #dbeafe;
  padding: 2px 8px;
  border-radius: 4px;
}

.dup-source-name {
  font-size: 0.88rem;
  font-weight: 700;
  color: #1e293b;
  flex: 1;
}

.dup-source-badge {
  font-size: 0.65rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.dup-source-badge.lecture { background: var(--lecture-bg); color: var(--lecture-text); }
.dup-source-badge.lab { background: var(--lab-bg); color: var(--lab-text); }
.dup-source-badge.tutorial { background: var(--tutorial-bg); color: var(--tutorial-text); }

.dup-source-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.74rem;
  color: #475569;
  font-weight: 600;
}

/* Day Mode Selector */
.dup-day-mode-toggle {
  display: flex;
  gap: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.dup-day-mode-toggle label {
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
}

/* Multi-Day Chips */
.dup-days-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.dup-day-chip {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: 20px;
  border: 1.5px solid var(--border-light);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--t-fast);
  user-select: none;
}

.dup-day-chip input {
  margin-right: 6px;
  cursor: pointer;
}

.dup-day-chip:has(input:checked) {
  background: #dbeafe;
  border-color: #2563eb;
  color: #1e40af;
  box-shadow: 0 1px 4px rgba(37, 99, 235, 0.15);
}

/* Duration badge & time tools */
.dup-duration-badge {
  font-size: 0.7rem;
  font-weight: 800;
  background: rgba(59, 130, 246, 0.12);
  color: #1d4ed8;
  padding: 2px 8px;
  border-radius: 10px;
}

.dup-time-tools {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #f1f5f9;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  flex-wrap: wrap;
  gap: 8px;
}

.dup-lock-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.74rem;
  font-weight: 700;
  color: #334155;
  cursor: pointer;
}

.dup-shift-buttons {
  display: flex;
  gap: 4px;
}

/* ══════════════════════════════════════════════════════════════════════════
   FLOATING CLIPBOARD ACTION BAR
   ══════════════════════════════════════════════════════════════════════════ */
.clipboard-bar {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3000;
  background: #ffffff;
  border: 2px solid #3b82f6;
  border-radius: 40px;
  box-shadow: 0 12px 32px rgba(37, 99, 235, 0.25), 0 4px 12px rgba(0, 0, 0, 0.1);
  padding: 8px 18px;
  animation: slideUp 200ms ease;
  max-width: 90vw;
}

.clipboard-content {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.clipboard-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.clipboard-icon {
  font-size: 1.4rem;
}

.clipboard-title {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.84rem;
  font-weight: 800;
  color: #0f172a;
}

.clipboard-tag {
  font-size: 0.65rem;
  font-weight: 800;
  background: #e2e8f0;
  color: #334155;
  padding: 1px 6px;
  border-radius: 4px;
  font-family: monospace;
}

.clipboard-duration {
  font-size: 0.68rem;
  font-weight: 700;
  background: #dbeafe;
  color: #1e40af;
  padding: 1px 6px;
  border-radius: 10px;
}

.clipboard-hint {
  font-size: 0.7rem;
  color: #64748b;
  font-weight: 500;
}

.clipboard-actions {
  display: flex;
  gap: 6px;
  align-items: center;
}

/* ══════════════════════════════════════════════════════════════════════════
   PASTE TARGET HIGHLIGHT ON EMPTY CELLS
   ══════════════════════════════════════════════════════════════════════════ */
body.clipboard-active .sched-empty {
  cursor: pointer !important;
  transition: background-color 150ms ease, border 150ms ease;
  position: relative;
}

body.clipboard-active .sched-empty:hover {
  background-color: rgba(59, 130, 246, 0.15) !important;
  outline: 2px dashed #2563eb !important;
  outline-offset: -2px;
}

body.clipboard-active .sched-empty:hover::after {
  content: '📋 Paste Here';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: #1e3a8a;
  color: #ffffff;
  font-size: 0.65rem;
  font-weight: 800;
  padding: 2px 6px;
  border-radius: 4px;
  pointer-events: none;
  white-space: nowrap;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
  z-index: 10;
}