:root {
  --bg-color: #f8fafc;
  --surface-color: #ffffff;
  --border-color: #e2e8f0;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --success: #16a34a;
  --danger: #dc2626;
  --danger-hover: #b91c1c;
  --warning: #d97706;
  --admin-badge: #7c3aed;
  --user-badge: #0284c7;
  --radius: 8px;
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  padding: 24px 16px;
}

.app-container {
  max-width: 1040px;
  margin: 0 auto;
}

/* Header */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 24px;
}

.brand h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
}

.tagline {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.user-header {
  display: flex;
  align-items: center;
  gap: 16px;
}

.user-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.username-display {
  font-weight: 600;
}

.interests-container {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

/* Badges */
.badge {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 9999px;
  color: #fff;
}

.badge.admin {
  background-color: var(--admin-badge);
}

.badge.user {
  background-color: var(--user-badge);
}

.chip {
  font-size: 0.75rem;
  background-color: #f1f5f9;
  color: #475569;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--border-color);
}

.count-badge {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Alerts */
.alert-banner {
  padding: 12px 16px;
  border-radius: var(--radius);
  margin-bottom: 20px;
  font-size: 0.9rem;
}

.alert-banner.success {
  background-color: #dcfce7;
  color: #15803d;
  border: 1px solid #bbf7d0;
}

.alert-banner.error {
  background-color: #fee2e2;
  color: #b91c1c;
  border: 1px solid #fecaca;
}

.alert-banner.info {
  background-color: #e0f2fe;
  color: #0369a1;
  border: 1px solid #bae6fd;
}

/* Cards */
.card {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 16px;
}

/* Forms */
.form-group {
  margin-bottom: 14px;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 4px;
}

input[type="text"],
input[type="email"],
input[type="password"],
textarea,
select {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  background-color: #fff;
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
}

.flex-1 { flex: 1; }
.align-end { align-self: flex-end; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.15s ease;
}

.btn-primary {
  background-color: var(--primary);
  color: #fff;
}
.btn-primary:hover { background-color: var(--primary-hover); }

.btn-secondary {
  background-color: #e2e8f0;
  color: #334155;
}
.btn-secondary:hover { background-color: #cbd5e1; }

.btn-success {
  background-color: var(--success);
  color: #fff;
}

.btn-danger {
  background-color: var(--danger);
  color: #fff;
}
.btn-danger:hover { background-color: var(--danger-hover); }

.btn-outline {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
}
.btn-outline:hover { background-color: #f1f5f9; }

.btn-block { width: 100%; }

.btn-sm {
  padding: 6px 12px;
  font-size: 0.8rem;
}

.btn-xs {
  padding: 4px 8px;
  font-size: 0.75rem;
}

.btn-group {
  display: flex;
  gap: 8px;
}

.demo-buttons {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--border-color);
}

.demo-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: block;
  margin-bottom: 6px;
}

/* Tabs */
.nav-tabs {
  display: flex;
  gap: 8px;
  border-bottom: 2px solid var(--border-color);
  margin-bottom: 20px;
}

.tab-btn {
  background: none;
  border: none;
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
}

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

.tab-content {
  display: none;
}
.tab-content.active {
  display: block;
}

.content-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.admin-toggle {
  background-color: #eff6ff;
  border: 1px solid #bfdbfe;
  padding: 6px 12px;
  border-radius: var(--radius);
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: #1e40af;
  cursor: pointer;
}

/* Grid & Cards */
.notes-grid,
.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
  margin-bottom: 20px;
}

.item-card {
  background: #fff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 16px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow);
}

.item-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
  margin-bottom: 8px;
}

.item-title {
  font-size: 1.05rem;
  font-weight: 600;
}

.item-content {
  font-size: 0.9rem;
  color: #334155;
  white-space: pre-wrap;
  margin-bottom: 14px;
  flex: 1;
}

.item-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  border-top: 1px solid #f1f5f9;
  padding-top: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.item-actions {
  display: flex;
  gap: 6px;
  margin-top: 8px;
}

/* Tables */
.table-responsive {
  overflow-x: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.data-table th,
.data-table td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.data-table th {
  background-color: #f8fafc;
  color: var(--text-muted);
  font-weight: 600;
}

/* Pagination */
.pagination-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Scenarios */
.scenario-badge {
  display: inline-block;
  background-color: #4338ca;
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
  margin-bottom: 8px;
}

.scenario-context {
  font-size: 0.85rem;
  color: #334155;
  background-color: #f8fafc;
  border-left: 3px solid var(--primary);
  padding: 8px 12px;
  margin: 10px 0 16px 0;
}

.agg-results-container {
  margin-top: 16px;
}

.interest-group-card {
  background: #fff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 12px 16px;
  margin-bottom: 10px;
}

.interest-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 6px;
}

/* Utilities */
.hidden { display: none !important; }

@media (max-width: 640px) {
  .auth-grid {
    grid-template-columns: 1fr;
  }
}