/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Primary Colors from ATLAS */
  --primary-color: #16A085;
  --primary-hover: #138D75;
  --secondary-color: #48BB78;
  --danger-color: #F56565;
  --warning-color: #ED8936;
  --info-color: #4299E1;
  --success-color: #38C77D;
  
  /* Background Colors */
  --bg-primary: #FFFFFF;
  --bg-secondary: #F8F9FA;
  --bg-tertiary: #E9ECEF;
  --sidebar-bg: #2C3E50;
  --sidebar-active: #16A085;
  
  /* Text Colors */
  --text-primary: #2D3748;
  --text-secondary: #718096;
  --text-tertiary: #A0AEC0;
  --text-white: #FFFFFF;
  
  /* Border Colors */
  --border-color: #E2E8F0;
  --border-light: #EDF2F7;
  
  /* Layout */
  --sidebar-width: 260px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.12);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
  background: var(--bg-secondary);
  color: var(--text-primary);
  line-height: 1.6;
  font-size: 14px;
}

/* Layout */
.layout {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  color: var(--text-white);
  display: flex;
  flex-direction: column;
  position: fixed;
  height: 100vh;
  overflow-y: auto;
  z-index: 1000;
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--primary-color);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
  color: white;
}

.logo-text {
  font-size: 16px;
  font-weight: 600;
  color: white;
}

.sidebar-nav {
  flex: 1;
  padding: 16px 0;
}

.nav-section {
  margin-bottom: 20px;
}

.nav-section-title {
  font-size: 11px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.5);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 8px 20px;
  margin-bottom: 4px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 20px;
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: all 0.2s;
  position: relative;
  font-size: 14px;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-white);
}

.nav-link.active {
  background: var(--sidebar-active);
  color: var(--text-white);
}

.nav-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.sidebar-footer {
  padding: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 36px;
  height: 36px;
  background: var(--primary-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 14px;
}

.user-details {
  flex: 1;
}

.user-name {
  font-size: 13px;
  font-weight: 600;
  color: white;
}

.user-role {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.6);
}

/* Main Content */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 24px;
  max-width: calc(100vw - var(--sidebar-width));
  background: var(--bg-secondary);
}

/* Page Header */
.page-header {
  margin-bottom: 24px;
  background: transparent;
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.page-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
}

.header-stats {
  display: flex;
  gap: 40px;
  align-items: center;
}

.header-stat-item {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 36px;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
}

.stat-number.unscheduled {
  color: var(--text-secondary);
}

.stat-label {
  display: block;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: 6px;
}

/* Filters Container */
.filters-container {
  background: var(--bg-primary);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-light);
  position: relative;
}

.filter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-bottom: 16px;
}

.filter-item {
  display: flex;
  flex-direction: column;
}

.filter-item label {
  display: block;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.filter-input,
.filter-select {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-size: 14px;
  background: var(--bg-primary);
  color: var(--text-primary);
  transition: all 0.2s;
  height: 38px;
}

.filter-input:focus,
.filter-select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(22, 160, 133, 0.1);
}

.clear-filters-btn {
  position: absolute;
  bottom: 20px;
  right: 20px;
  padding: 8px 16px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.clear-filters-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-secondary);
}

/* Timetable Version Box */
.timetable-version {
  background: #2C3E50;
  color: var(--text-white);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-card);
}

.version-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 24px;
}

.version-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.version-label {
  font-size: 11px;
  font-weight: 600;
  opacity: 0.7;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.version-value {
  font-size: 18px;
  font-weight: 700;
  color: white;
}

.status-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  width: fit-content;
}

.status-generated {
  background: var(--success-color);
  color: white;
}

/* Day Section */
.day-section {
  margin-bottom: 24px;
}

.day-header {
  background: var(--bg-primary);
  padding: 16px 20px;
  border-radius: 8px;
  margin-bottom: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
}

.day-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.day-count {
  font-size: 14px;
  color: var(--text-secondary);
  font-weight: 500;
}

/* Class Cards */
.class-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 16px;
}

.class-card {
  background: var(--bg-primary);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  padding: 16px;
  transition: all 0.2s;
  cursor: pointer;
  box-shadow: var(--shadow-card);
}

.class-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--border-color);
}

.card-time {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.card-time svg {
  width: 14px;
  height: 14px;
  stroke: var(--text-tertiary);
}

.card-time-value {
  background: var(--bg-tertiary);
  padding: 4px 8px;
  border-radius: 4px;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 12px;
}

.card-subject {
  margin-bottom: 14px;
}

.subject-badge {
  display: inline-block;
  background: var(--primary-color);
  color: white;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.3px;
  margin-bottom: 8px;
}

.subject-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
}

.card-info {
  display: grid;
  gap: 8px;
}

.card-info-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
}

.card-info-row svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  stroke: var(--text-tertiary);
}

/* Loading State */
.loading-state {
  text-align: center;
  padding: 60px 20px;
  background: var(--bg-primary);
  border-radius: 8px;
  border: 1px solid var(--border-light);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-color);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 16px;
}

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

.loading-state p {
  color: var(--text-secondary);
  font-size: 14px;
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  background: var(--bg-primary);
  border-radius: 8px;
  border: 1px solid var(--border-light);
}

.empty-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.3;
}

.empty-state h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.empty-state p {
  color: var(--text-secondary);
  font-size: 14px;
}

/* Modal Styles */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  padding: 20px;
}

.modal-content {
  background: var(--bg-primary);
  border-radius: 8px;
  max-width: 800px;
  width: 100%;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: var(--bg-tertiary);
  border-radius: 50%;
  font-size: 20px;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  line-height: 1;
}

.modal-close:hover {
  background: var(--border-color);
}

.modal-body {
  padding: 24px;
  overflow-y: auto;
  flex: 1;
}

.schedule-list {
  display: grid;
  gap: 12px;
}

.schedule-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  background: var(--bg-secondary);
  border-radius: 8px;
  border: 1px solid var(--border-light);
}

.schedule-time-badge {
  background: var(--primary-color);
  color: white;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
  height: fit-content;
}

.schedule-details {
  flex: 1;
}

.schedule-subject {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.schedule-meta {
  font-size: 13px;
  color: var(--text-secondary);
}

/* Tabs */
.tabs-container {
  display: flex;
  gap: 4px;
  margin-bottom: 0;
  border-bottom: 1px solid var(--border-light);
  background: var(--bg-primary);
  padding: 16px 20px 0;
  border-radius: 8px 8px 0 0;
  border: 1px solid var(--border-light);
  border-bottom: none;
}

.tab-button {
  padding: 10px 20px;
  border: none;
  background: transparent;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  position: relative;
  transition: all 0.2s;
  border-radius: 6px 6px 0 0;
}

.tab-button:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
}

.tab-button.active {
  color: var(--primary-color);
  background: transparent;
}

.tab-button.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary-color);
}

.tab-content {
  display: none;
  background: var(--bg-primary);
  padding: 24px;
  border-radius: 0 0 8px 8px;
  border: 1px solid var(--border-light);
  border-top: none;
}

.tab-content.active {
  display: block;
}

/* Unscheduled Items */
.unscheduled-list {
  background: var(--bg-primary);
}

.unscheduled-items {
  display: grid;
  gap: 12px;
}

.unscheduled-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  transition: all 0.2s;
}

.unscheduled-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--border-color);
}

.unscheduled-icon {
  width: 48px;
  height: 48px;
  background: var(--bg-tertiary);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.unscheduled-details {
  flex: 1;
}

.unscheduled-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.unscheduled-meta {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.unscheduled-reason {
  font-size: 12px;
  color: var(--text-tertiary);
  padding: 4px 10px;
  background: var(--bg-tertiary);
  border-radius: 4px;
  display: inline-block;
}

/* Responsive Design */
@media (max-width: 1200px) {
  .class-cards-grid {
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  }
}

@media (max-width: 1024px) {
  .sidebar {
    width: 220px;
  }
  
  .main-content {
    margin-left: 220px;
  }
  
  .filter-grid {
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  }
}

@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.3s;
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
    max-width: 100vw;
    padding: 16px;
  }
  
  .header-top {
    flex-direction: column;
    gap: 16px;
  }
  
  .header-stats {
    width: 100%;
    justify-content: space-around;
  }
  
  .filter-grid {
    grid-template-columns: 1fr;
  }
  
  .class-cards-grid {
    grid-template-columns: 1fr;
  }
  
  .version-info {
    grid-template-columns: 1fr 1fr;
  }
  
  .page-title {
    font-size: 24px;
  }
  
  .stat-number {
    font-size: 28px;
  }
}

/* School Color Variations */
.subject-badge[data-school="7"],
.class-card[data-school="7"] .subject-badge { 
  background: #E12A7B; 
}

.subject-badge[data-school="8"],
.class-card[data-school="8"] .subject-badge { 
  background: #009FE0; 
}

.subject-badge[data-school="11"],
.class-card[data-school="11"] .subject-badge { 
  background: #ED1A3B; 
}

.subject-badge[data-school="13"],
.class-card[data-school="13"] .subject-badge { 
  background: #ED1A3B; 
}

.subject-badge[data-school="16"],
.class-card[data-school="16"] .subject-badge { 
  background: #CC5500; 
}

/* Scrollbar Styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-tertiary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb {
  background: var(--text-tertiary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* Buttons */
.btn {
  padding: 10px 20px;
  border: none;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

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

.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-secondary);
  border-color: var(--text-secondary);
}

/* Feedback Button */
.feedback-btn {
  position: fixed;
  top: 24px;
  right: 24px;
  padding: 8px 16px;
  background: white;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s;
  z-index: 100;
}

.feedback-btn:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--text-secondary);
}

/* Timetable Cards Container */
.timetable-cards {
  display: grid;
  gap: 16px;
}