/* One node's equation, built edge by edge */

:where(.scene-gen) .gen-layout {
  display: grid;
  grid-template-columns: minmax(150px, 0.5fr) minmax(0, 1.5fr);
  gap: 16px;
}

:where(.scene-gen) .gen-panel {
  min-width: 0;
  padding: 14px 16px;
  background: var(--surface-muted);
  border-radius: var(--radius);
}

/* Capped like every other figure's graph: the generic `.scene svg` cap is 1000px,
   which for a 210-unit viewBox is a fivefold blow-up on a phone, where the panel
   also has the column to itself. */
:where(.scene-gen) .gen-cfg svg {
  width: 100%;
  max-width: 260px;
  height: auto;
  margin-inline: auto;
}

/* An edge this step is not about stays legible but recedes. */
:where(.scene-gen) .gen-edge line,
:where(.scene-gen) .gen-edge path {
  fill: none;
  stroke: var(--border-strong);
  stroke-width: 1.5;
  transition:
    stroke 200ms ease,
    stroke-width 200ms ease;
}

:where(.scene-gen) .gen-edge text {
  fill: var(--text-muted);
  font: 0.52rem var(--mono);
  transition: fill 200ms ease;
}

/* The head is a separate marker rather than the same one recoloured: a marker
   does not inherit the stroke of the edge that placed it. */
:where(.scene-gen) .gen-arrow-hl {
  fill: var(--accent);
}

:where(.scene-gen) .gen-edge.is-hl line,
:where(.scene-gen) .gen-edge.is-hl path {
  stroke: var(--accent);
  stroke-width: 2.5;
  marker-end: url("#gen-arrow-hl");
}

:where(.scene-gen) .gen-edge.is-hl text {
  fill: var(--accent);
  font-weight: 700;
}

:where(.scene-gen) .gen-node circle {
  fill: var(--surface);
  stroke: var(--border-strong);
  stroke-width: 1.5;
}

/* The node whose equation the panel is showing. */
:where(.scene-gen) .gen-node {
  cursor: pointer;
}

:where(.scene-gen) .gen-node circle {
  transition:
    fill 150ms ease,
    stroke 150ms ease;
}

:where(.scene-gen) .gen-node.is-hl circle {
  fill: var(--accent-soft);
  stroke: var(--accent);
  stroke-width: 2.5;
}

:where(.scene-gen) .gen-node:focus-visible {
  outline: none;
}

:where(.scene-gen) .gen-node:focus-visible circle {
  stroke: var(--accent);
  stroke-width: 3;
}

:where(.scene-gen) .gen-node text {
  fill: var(--text);
  font: 700 0.6rem var(--mono);
  text-anchor: middle;
}

/* One cell for every derivation: the panel is as tall as the tallest, so
   switching between them cannot move the graph the cursor is hovering. */
:where(.scene-gen) .gen-stack {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-content: start;
}

:where(.scene-gen) .gen-stack .gen-build {
  grid-column: 1;
  grid-row: 2;
  visibility: hidden;
}

:where(.scene-gen) .gen-stack .gen-build.is-shown {
  visibility: visible;
}

:where(.scene-gen) .gen-code {
  margin: 4px 0 0;
  overflow-x: auto;
  font-size: 0.78rem;
  line-height: 1.6;
}

:where(.scene-gen) .gen-hint {
  margin: 10px 0 0;
  color: var(--text-faint);
  font-size: 0.78rem;
  font-style: italic;
  text-align: center;
}

/* The derivation: numbered steps, with the per-edge contributions nested under
   the step that makes them, so the indentation is the containment. */
:where(.scene-gen) .gen-head {
  margin: 0 0 10px;
  font-size: 0.9rem;
}

:where(.scene-gen) .gen-head small {
  margin-left: 6px;
  color: var(--text-muted);
  font-size: 0.76rem;
}

:where(.scene-gen) .gen-list,
:where(.scene-gen) .gen-list ul {
  margin: 0;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 0.82rem;
}

:where(.scene-gen) .gen-list > li {
  margin-bottom: 10px;
}

:where(.scene-gen) .gen-list ul {
  margin-top: 6px;
  padding-left: 14px;
  list-style: none;
}

:where(.scene-gen) .gen-list ul > li {
  margin-bottom: 6px;
  border-left: 2px solid var(--border);
  padding-left: 10px;
}

:where(.scene-gen) .gen-tag {
  font: 700 0.74rem var(--mono);
  color: var(--accent);
}

:where(.scene-gen) .gen-act {
  margin-left: 6px;
  font: 0.74rem var(--mono);
}

@media (max-width: 860px) {
  :where(.scene-gen) .gen-layout {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* A second graph, whose nodes carry names rather than single letters. */
:where(.scene-gen) .gen-node rect {
  fill: var(--surface);
  stroke: var(--border-strong);
  stroke-width: 1.5;
  transition:
    fill 150ms ease,
    stroke 150ms ease;
}

:where(.scene-gen) .gen-node.is-hl rect {
  fill: var(--accent-soft);
  stroke: var(--accent);
  stroke-width: 2.5;
}

:where(.scene-gen) .gen-node:focus-visible rect {
  stroke: var(--accent);
  stroke-width: 3;
}

:where(.scene-gen) .gen-node rect + text {
  font-size: 0.52rem;
}

:where(.scene-gen, .scene-walk, .scene-ctxkey) .gen-cluster {
  fill: var(--text-faint);
  font: 700 0.56rem var(--mono);
  letter-spacing: 0.06em;
}