.two-column-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.manual-card .hint {
  margin-top: 0.75rem;
  font-size: 0.9rem;
}

.manual-controls {
  margin-top: 0.75rem;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.example-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.data-actions {
  margin-top: 1rem;
  border-top: 1px solid var(--app-border);
  padding-top: 1rem;
}
.column-selectors {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}
.regression-equation-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
}
.regression-equation-text {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 1.1rem;
  background: #f1f4f8;
  padding: 1rem;
  border-radius: 8px;
  color: #1e40af;
  margin: 0;
  text-align: center;
}
.regression-equation-text em {
  font-style: normal;
  color: #1d4ed8; /* A slightly different blue to stand out */
}
.tool-directory,
.chart-card,
.metrics-panel,
.summary-section {
  /* Rely on shared styles; this file only tweaks layout where needed. */
}

.advanced-card {
  margin-top: 1rem;
}

.advanced-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-top: 0.75rem;
}

.advanced-block h3 {
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

.reference-selector {
  margin-top: 1rem;
}

/* ========================================
   PROFESSOR MODE TUTORIAL STYLES
   ======================================== */

/* Toggle switch in header */
.professor-mode-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 6px 12px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    color: white;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.professor-mode-toggle:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.professor-mode-toggle input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: #fbbf24;
}

/* Professor Mode styles are now in shared/css/main.css */