/* === CSS Variables === */
:root {
  --bg: #0a0a0a;
  --surface: #141414;
  --surface-elevated: #1e1e1e;
  --surface-hover: #262626;
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --text-muted: #666666;
  --accent: #e53935;
  --accent-hover: #ff5252;
  --accent-glow: rgba(229, 57, 53, 0.3);
  --border: #2a2a2a;
  --success: #4caf50;
  --radius: 12px;
  --radius-sm: 8px;
  --transition-duration: 200ms;

  /* Time of day colors (warm gradient) */
  --time-morning: #f59e0b;    /* Golden/Yellow - before 12pm */
  --time-afternoon: #f97316;  /* Orange - 12pm to 6pm */
  --time-evening: #ef4444;    /* Red/Pink - after 6pm */
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

/* === App Container === */
#app {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 16px;
  padding-bottom: 40px;
}

/* === Header === */
.header {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 2px;
}

.logo span {
  color: var(--accent);
}

.refresh-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, transform 0.2s;
}

.refresh-btn:hover {
  background: var(--surface-elevated);
}

.refresh-btn.spinning svg {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* === Views === */
.view {
  display: none;
  opacity: 0;
  transition: opacity var(--transition-duration) ease-out;
}

.view.active {
  display: block;
  opacity: 1;
}

.view.fade-out {
  opacity: 0;
}

.view-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.view-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
}

.back-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  background: var(--surface);
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: background 0.2s;
}

.back-btn:hover {
  background: var(--surface-elevated);
  color: var(--text-primary);
}

/* === Mode Selection === */
.mode-container {
  text-align: center;
  padding: 40px 0;
}

.mode-container h2 {
  font-size: 1.5rem;
  margin-bottom: 32px;
}

.mode-buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.mode-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 32px 16px;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: all 0.2s;
}

.mode-btn:hover {
  background: var(--surface-elevated);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.mode-btn svg {
  color: var(--accent);
}

.mode-title {
  font-size: 1rem;
  font-weight: 600;
}

.mode-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* === Calendar View === */
.calendar-container {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.week-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.week-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Divider between calendar and instructors */
.divider {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 32px 0;
  color: var(--text-muted);
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.divider span {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Section label for instructors on home */
.section-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
}

.instructors-section .search-container {
  margin-bottom: 16px;
}

.week-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 8px;
}

.day-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 14px 6px;
  background: var(--surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  transition: all 0.2s;
  text-align: center;
}

.day-card:hover:not(:disabled) {
  background: var(--surface-elevated);
  border-color: var(--text-muted);
  transform: translateY(-2px);
}

.day-card:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.day-card.today {
  border-color: var(--accent);
  box-shadow: 0 0 12px var(--accent-glow);
}

.day-card .day-name {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.day-card .day-num {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 4px 0;
}

.day-card.today .day-num {
  color: var(--accent);
}

.day-card .day-focus {
  font-size: 0.65rem;
  color: var(--text-muted);
  line-height: 1.3;
  min-height: 2.6em;
  display: flex;
  align-items: center;
}

.day-card .day-count {
  font-size: 0.7rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Day card tap feedback */
.day-card.tapped {
  transform: scale(0.95);
  background: var(--accent);
  border-color: var(--accent);
}

.day-card.tapped .day-num,
.day-card.tapped .day-name,
.day-card.tapped .day-focus,
.day-card.tapped .day-count {
  color: white;
}

/* Last visited highlight */
.day-card.last-visited {
  border-color: var(--accent);
  box-shadow: 0 0 12px var(--accent-glow);
  animation: fade-highlight 300ms ease-out forwards;
}

@keyframes fade-highlight {
  0% { box-shadow: 0 0 12px var(--accent-glow); border-color: var(--accent); }
  100% { box-shadow: none; border-color: var(--border); }
}

/* === Time Slots View === */
.day-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
}

.day-date {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.focus-badge {
  display: inline-block;
  padding: 8px 16px;
  background: var(--accent);
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.location-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

/* Ensure instructor detail tabs are visible */
.instructor-location-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

.tab {
  flex: 1;
  padding: 12px;
  background: var(--surface);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 150ms ease-out;
}

.tab:hover {
  background: var(--surface-elevated);
}

.tab.active {
  background: var(--accent);
  color: var(--text-primary);
}

.classes-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: opacity 150ms ease-out;
}

.classes-list.fade {
  opacity: 0.3;
}

.class-card {
  display: flex;
  align-items: center;
  padding: 16px;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: all 0.2s;
}

.class-card:hover {
  background: var(--surface-elevated);
  border-color: var(--text-muted);
  transform: translateX(4px);
}

.class-time {
  font-size: 1rem;
  font-weight: 600;
  min-width: 80px;
  color: var(--accent);
}

/* Time of day color classes */
.class-time.morning { color: var(--time-morning); }
.class-time.afternoon { color: var(--time-afternoon); }
.class-time.evening { color: var(--time-evening); }

.class-details {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.class-instructor {
  font-weight: 500;
}

.class-location {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.sub-badge {
  display: inline-block;
  padding: 2px 6px;
  background: var(--surface-elevated);
  border-radius: 4px;
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-left: 8px;
}

/* Class card actions container */
.class-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

/* Hide icons on desktop */
.class-actions .btn-icon {
  display: none;
}

.book-btn {
  padding: 8px 16px;
  background: var(--accent);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  transition: background 0.2s;
  text-decoration: none;
  color: inherit;
  display: flex;
  align-items: center;
  justify-content: center;
}

.class-card:hover .book-btn {
  background: var(--accent-hover);
}

/* Copy button */
.copy-btn {
  padding: 8px 12px;
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 34px;
  box-sizing: border-box;
}

.copy-btn:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.copy-btn.copied {
  background: var(--success);
  border-color: var(--success);
  color: white;
}

.copy-btn.copied .btn-text,
.copy-btn.copied .btn-icon {
  display: none;
}

.copy-btn.copied::after {
  content: '✓';
  font-size: 14px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* === Instructor Views === */
.search-container {
  margin-bottom: 20px;
}

.search-input {
  width: 100%;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 1rem;
}

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

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

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

.instructor-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px;
  background: var(--surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  transition: all 0.2s;
}

.instructor-item:hover {
  background: var(--surface-elevated);
  border-color: var(--text-muted);
}

.instructor-item .name {
  font-weight: 500;
}

.instructor-item .count {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Starred instructor in list */
.instructor-item.starred-instructor {
  border-color: var(--accent);
  background: rgba(229, 57, 53, 0.08);
}

/* Instructor item right section */
.instructor-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Star button */
.star-btn {
  font-size: 1.1rem;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  transition: color 0.2s, transform 0.2s;
}

.star-btn:hover {
  color: var(--accent);
  transform: scale(1.15);
}

.star-btn.starred {
  color: var(--accent);
}

/* Star button in instructor detail header */
.detail-star {
  margin-left: 8px;
  vertical-align: middle;
}

/* Star indicator in class cards */
.star-indicator {
  color: var(--accent);
  margin-right: 4px;
}

/* Starred instructor class highlight */
.class-card.starred-instructor {
  border-color: var(--accent);
  background: rgba(229, 57, 53, 0.08);
}

.instructor-header h2 {
  font-size: 1.25rem;
}

.class-count {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.instructor-classes {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.location-section h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.class-card-full {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: all 0.2s;
}

.class-card-full:hover {
  background: var(--surface-elevated);
  border-color: var(--text-muted);
}

.class-card-full .class-date-time {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 90px;
}

.class-card-full .date {
  font-weight: 500;
}

.class-card-full .time {
  color: var(--accent);
  font-weight: 600;
}

/* Time of day colors for instructor view */
.class-card-full .time.morning { color: var(--time-morning); }
.class-card-full .time.afternoon { color: var(--time-afternoon); }
.class-card-full .time.evening { color: var(--time-evening); }

.class-card-full .focus {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Class info row with focus and location */
.class-card-full .class-info {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* Location badge in instructor view */
.location-badge {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--surface-elevated);
  border-radius: 4px;
  color: var(--text-secondary);
  width: fit-content;
}

/* Fade animation for instructor classes */
.instructor-classes {
  transition: opacity 150ms ease-out;
}

.instructor-classes.fade {
  opacity: 0.3;
}

/* === Loading === */
.loading {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(10, 10, 10, 0.9);
  justify-content: center;
  align-items: center;
  flex-direction: column;
  gap: 16px;
  z-index: 100;
}

.loading.active {
  display: none; /* Disabled - shows too quickly and causes jitter */
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* === Footer === */
.footer {
  display: none;
}

/* === Responsive === */
@media (max-width: 480px) {
  #app {
    padding: 0 12px;
  }

  .week-section {
    overflow-x: hidden;
  }

  .week-grid {
    gap: 4px;
    width: 100%;
  }

  .day-card {
    padding: 10px 2px;
  }

  .day-card .day-name {
    font-size: 0.6rem;
  }

  .day-card .day-num {
    font-size: 1.2rem;
  }

  .day-card .day-focus {
    font-size: 0.55rem;
  }

  .mode-buttons {
    grid-template-columns: 1fr;
  }

  .mode-btn {
    flex-direction: row;
    gap: 16px;
    padding: 20px;
    text-align: left;
  }

  .mode-btn svg {
    flex-shrink: 0;
  }

  .class-time {
    min-width: 70px;
    font-size: 0.9rem;
  }

  /* Show icons, hide text on mobile */
  .class-actions .btn-text {
    display: none;
  }

  .class-actions .btn-icon {
    display: block;
  }

  .copy-btn, .book-btn {
    padding: 8px;
    width: 34px;
    height: 34px;
  }
}

/* === Empty State === */
.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary);
}

.empty-state svg {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  opacity: 0.5;
}

/* === Toast Notification === */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 20px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  z-index: 200;
  opacity: 0;
  transition: transform 0.3s ease-out, opacity 0.3s ease-out;
  pointer-events: none;
}

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

/* === Instructor Card Slide Animation === */
.instructor-item {
  transition: all 0.2s, transform 0.4s ease-out, opacity 0.4s ease-out;
}

.instructor-item.slide-animate {
  transition: transform 0.4s ease-out, opacity 0.4s ease-out, background 0.4s ease-out, border-color 0.4s ease-out;
}