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

:root {
  --primary: #3b82f6;
  --secondary: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --dark: #1f2937;
  --light: #f3f4f6;
  --border: #e5e7eb;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: var(--dark);
  min-height: 100vh;
  padding: 20px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  background: white;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
  overflow: hidden;
}

header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 40px 20px;
  text-align: center;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
}

header p {
  font-size: 1rem;
  opacity: 0.9;
}

/* ============ TABS ============ */
.tabs {
  display: flex;
  border-bottom: 2px solid var(--border);
  background: var(--light);
}

.tab-btn {
  flex: 1;
  padding: 16px 20px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--dark);
  transition: all 0.3s ease;
  border-bottom: 3px solid transparent;
}

.tab-btn:hover {
  background: rgba(59, 130, 246, 0.05);
}

.tab-btn.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.tab-content {
  display: none;
  padding: 40px;
  animation: fadeIn 0.3s ease;
}

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

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============ FORMS ============ */
.form {
  max-width: 600px;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: var(--dark);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-group textarea {
  min-height: 100px;
  resize: vertical;
}

/* Rating stars */
.rating {
  display: flex;
  gap: 8px;
  font-size: 2rem;
  margin-bottom: 8px;
}

.star {
  cursor: pointer;
  color: #cbd5e0;
  transition: all 0.2s ease;
  user-select: none;
}

.star:hover,
.star.hover {
  color: #f59e0b;
  transform: scale(1.1);
}

.star.active {
  color: #fbbf24;
  transform: scale(1.05);
}

.rating-text {
  font-size: 0.9rem;
  color: #6b7280;
  margin-left: 8px;
  font-weight: 500;
}

/* ============ BUTTONS ============ */
.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

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

.btn-primary:hover {
  background: #2563eb;
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(59, 130, 246, 0.2);
}

.btn-secondary {
  background: var(--light);
  color: var(--dark);
  border: 1px solid var(--border);
}

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

.btn-danger {
  background: var(--danger);
  color: white;
  padding: 8px 12px;
  font-size: 0.9rem;
}

.btn-danger:hover {
  background: #dc2626;
}

/* ============ CARDS ============ */
.card {
  background: var(--light);
  border-radius: 8px;
  padding: 24px;
  margin-bottom: 24px;
  border: 1px solid var(--border);
}

.card h3 {
  margin-bottom: 16px;
  color: var(--dark);
}

/* ============ ANALYTICS ============ */
.analytics-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 24px;
}

.analytics-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.analytics-item {
  padding: 12px;
  background: white;
  border-radius: 6px;
  border-left: 4px solid var(--primary);
}

.analytics-item strong {
  display: block;
  margin-bottom: 4px;
  color: var(--dark);
}

.analytics-item small {
  color: #6b7280;
  font-size: 0.9rem;
}

/* ============ SESSIONS LIST ============ */
.sessions-controls {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}

#searchInput {
  flex: 1;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
}

.sessions-list {
  display: grid;
  gap: 16px;
}

.session-card {
  background: var(--light);
  border-radius: 8px;
  padding: 20px;
  border-left: 4px solid var(--primary);
  transition: all 0.3s ease;
}

.session-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

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

.session-header h4 {
  color: var(--dark);
  margin: 0;
}

.session-meta {
  font-size: 0.9rem;
  color: #6b7280;
  margin-bottom: 12px;
}

.session-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-right: 8px;
  margin-bottom: 8px;
}

.badge-tool {
  background: #dbeafe;
  color: #1e40af;
}

.badge-category {
  background: #dcfce7;
  color: #166534;
}

.badge-quality {
  background: #fef3c7;
  color: #92400e;
}

.badge-model {
  background: #e9d5ff;
  color: #6b21a8;
}

.session-content {
  margin: 12px 0;
  font-size: 0.95rem;
  line-height: 1.6;
}

.session-content strong {
  display: block;
  margin-top: 8px;
  color: var(--dark);
}

.session-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

/* ============ WEEKLY SUMMARY ============ */
.weekly-summary-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.weekly-data {
  background: var(--light);
  padding: 16px;
  border-radius: 8px;
  font-size: 0.95rem;
  line-height: 1.8;
}

.weekly-stat {
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.weekly-stat:last-child {
  border-bottom: none;
}

.weekly-stat strong {
  display: block;
  color: var(--dark);
}

.weekly-stat span {
  color: var(--primary);
  font-weight: 600;
  font-size: 1.2rem;
}

/* ============ FOOTER ============ */
footer {
  background: var(--light);
  padding: 20px;
  text-align: center;
  color: #6b7280;
  border-top: 1px solid var(--border);
}

/* ============ UTILITIES ============ */
.loading {
  text-align: center;
  color: #9ca3af;
  padding: 20px;
}

@media (max-width: 768px) {
  .container {
    border-radius: 0;
  }

  header h1 {
    font-size: 1.75rem;
  }

  .tabs {
    flex-wrap: wrap;
  }

  .tab-btn {
    flex: 1 1 50%;
  }

  .tab-content {
    padding: 20px;
  }

  .analytics-container {
    grid-template-columns: 1fr;
  }

  .weekly-summary-container {
    grid-template-columns: 1fr;
  }
}