.layout-grid {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-md);
}

.controls-sidebar {
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  align-items: center;
}

.controls-sidebar h3 {
  width: 100%;
  margin-bottom: var(--spacing-sm);
}

.control-group {
  flex: 1;
  min-width: 180px;
  margin-bottom: 0;
}

.control-group label {
  display: block;
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

.control-group span {
  color: var(--primary);
  font-weight: bold;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--primary);
}

.box-visualizer {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.box-column {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.box-title {
  font-size: 1.1rem;
  color: var(--text-primary);
  text-align: center;
  border-bottom: 2px solid var(--border);
  padding-bottom: var(--spacing-sm);
}

.math-panel {
  background: var(--surface);
  padding: var(--spacing-md);
  border-radius: var(--radius);
  font-size: 0.9rem;
  border: 1px solid var(--border);
}

.formula {
  margin-top: var(--spacing-sm);
  color: var(--secondary);
}

/* Visualization Layers */
.scene {
  background: var(--bg-color);
  padding: var(--spacing-lg);
  border-radius: var(--radius);
  border: 1px dashed var(--border);
  min-height: 400px;
  display: flex;
  justify-content: center;
}

/* Margin Layer (Orange) */
.margin-area {
  background-color: rgba(255, 165, 0, 0.2);
  border: 1px dashed orange;
  position: relative;
  transition: all 0.2s ease;
  flex-shrink: 0;
}

/* Border Layer (Yellow) */
.border-area {
  background-color: rgba(255, 255, 0, 0.4);
  position: relative;
  transition: all 0.2s ease;
}

/* Padding Layer (Green) */
.padding-area {
  background-color: rgba(0, 128, 0, 0.2);
  border: 1px dashed green;
  position: relative;
  transition: all 0.2s ease;
}

/* Content Layer (Blue) */
.content-area {
  background-color: rgba(0, 0, 255, 0.2);
  border: 1px dashed blue;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: all 0.2s ease;
  min-height: 50px; /* arbitrary height to give substance */
  text-align: center;
  font-weight: bold;
  font-size: 0.85rem;
}

.label {
  position: absolute;
  top: 2px;
  left: 4px;
  font-size: 0.55rem;
  font-weight: 700;
  text-transform: uppercase;
  color: rgba(0,0,0,0.4);
  pointer-events: none;
  letter-spacing: 0.05em;
}

/* The actual models respect sizings */
.content-box-model .content-area {
  box-sizing: content-box;
}
.border-box-model .content-area {
  box-sizing: border-box;
}