.diagram-primitives {
  position: relative;
  width: 100%;
  min-height: min(var(--diagram-min-height, 280px), 52vh);
  aspect-ratio: var(--diagram-aspect-ratio, 16 / 9);
  overflow: hidden;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  background: var(--surface-base);
}

.diagram-primitives__svg {
  display: block;
  width: 100%;
  height: 100%;
  min-height: inherit;
  font-family: var(--font-ui);
  color: var(--text-primary);
  user-select: none;
}

.diagram-primitives__grid-line {
  stroke: #DDE4EE;
  stroke-width: 1.35;
  vector-effect: non-scaling-stroke;
}

.diagram-primitives__grid-line--minor {
  stroke: #EDF1F6;
  stroke-width: 1;
}

.diagram-primitives__axis,
.diagram-primitives__tick {
  stroke: #354158;
  stroke-width: 1.8;
  vector-effect: non-scaling-stroke;
}

.diagram-primitives__tick-label {
  fill: var(--text-muted);
  font-size: 16px;
  font-weight: var(--weight-medium);
}

.diagram-primitives__label {
  fill: currentColor;
  font-size: 19px;
  font-weight: var(--weight-semibold);
  paint-order: stroke;
  stroke: var(--surface-base);
  stroke-width: 5px;
  stroke-linejoin: round;
}

.diagram-primitives__line,
.diagram-primitives__curve {
  stroke: currentColor;
  stroke-width: 3;
  vector-effect: non-scaling-stroke;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.diagram-primitives__curve { stroke-width: 3.5; }
.diagram-primitives__line--dashed { stroke-dasharray: 9 8; }
.diagram-primitives__arrow-head { fill: currentColor; }

.diagram-primitives__region {
  stroke-width: 1.5;
  vector-effect: non-scaling-stroke;
}

.diagram-primitives__point {
  fill: currentColor;
  stroke: var(--surface-base);
  stroke-width: 4;
  vector-effect: non-scaling-stroke;
}

.diagram-primitives__handle {
  cursor: grab;
  stroke-width: 5;
  filter: drop-shadow(0 2px 3px rgba(23, 32, 51, 0.18));
}

.diagram-primitives__handle:active { cursor: grabbing; }
.diagram-primitives__handle:focus-visible {
  outline: none;
  stroke: var(--focus-ring);
  stroke-width: 7;
}

.diagram-primitives__tone--default { color: var(--text-primary); }
.diagram-primitives__tone--axis { color: #354158; }
.diagram-primitives__tone--primary,
.diagram-primitives__tone--curve { color: #175CD3; }
.diagram-primitives__tone--accent { color: #7A5AF8; }
.diagram-primitives__tone--tangent { color: #B54708; }
.diagram-primitives__tone--point { color: #0F766E; }
.diagram-primitives__tone--interactive,
.diagram-primitives__tone--handle { color: #0F766E; }
.diagram-primitives__tone--region { color: #12B76A; }
.diagram-primitives__tone--warning { color: #B54708; }

.diagram-primitives__slider {
  display: grid;
  gap: var(--space-2);
  min-width: min(100%, 240px);
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--surface-base);
}

.diagram-primitives__slider-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
}

.diagram-primitives__slider-label {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
}

.diagram-primitives__slider-value {
  min-width: 3ch;
  text-align: right;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.diagram-primitives__slider-input {
  width: 100%;
  min-height: var(--touch-target-min);
  accent-color: var(--mode-accent, #0F766E);
}

@media (max-width: 680px) {
  .diagram-primitives {
    min-height: min(var(--diagram-min-height, 250px), 44vh);
    aspect-ratio: 4 / 3;
  }

  .diagram-primitives__tick-label { font-size: 18px; }
  .diagram-primitives__label { font-size: 21px; }
  .diagram-primitives__slider { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .diagram-primitives__handle { filter: none; }
}