/*
 * Interactive-demo components shared across the maths posts. Loaded after
 * css/post.css, which carries the page chrome (.topic, .la-index, .controls,
 * .readout, canvas sizing, …).
 *
 * Each block notes which engine builds the markup, so a change here can be
 * traced to the JS that depends on it.
 */

/* ---------------------------------------------------------------- heatmap */
/* Built by Heatmap in js/prob-engine.js. Used by the probability post (joint /
   marginal / conditional / independence), information theory (mutual
   information, InfoNCE similarity matrix). */

.heatmap-box {
  display: grid;
  gap: 2px;
  margin: 0 0 .6rem;
  /* Set by Heatmap once it knows the grid size. */
  grid-template-columns: auto repeat(var(--cols, 5), 1fr);
}

.heatmap-cell {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 3px;
  font-size: .72rem;
  font-variant-numeric: tabular-nums;
  cursor: ns-resize;
  user-select: none;
  transition: outline-color .12s ease;
  outline: 2px solid transparent;
}

.heatmap-cell.selected { outline-color: #f97316; }
.heatmap-cell.dimmed { opacity: .28; }

/* Row/column sums drawn alongside the grid during marginalization. */
.heatmap-margin {
  display: grid;
  place-items: center;
  font-size: .72rem;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

.heatmap-axis {
  font-size: .7rem;
  color: var(--muted);
  display: grid;
  place-items: center;
}

/* ------------------------------------------------------------- bar racks */
/* Drag-to-reshape discrete distributions. Built by BarRack in the information
   theory post's interactive.js (entropy, coding, perplexity). */

.bar-rack {
  display: grid;
  gap: 4px;
  align-items: end;
  height: 190px;
  margin: 0 0 .5rem;
  padding: .4rem .3rem 0;
  border: 1px solid var(--line, #e2e2e2);
  border-radius: 6px;
  background: #fff;
  touch-action: none;
}

.bar-col {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
  height: 100%;
  cursor: ns-resize;
  user-select: none;
}

.bar-col .bar-fill {
  width: 100%;
  border-radius: 3px 3px 0 0;
  background: rgba(6, 69, 173, .55);
  transition: background .12s ease;
}

.bar-col.reference .bar-fill { background: rgba(140, 140, 140, .45); }
.bar-col:focus-visible { outline: 2px solid #f97316; outline-offset: 2px; }

.bar-col .bar-label {
  font-size: .68rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  padding-top: 2px;
}

/* ------------------------------------------------------------ token cells */
/* Small labelled chips laid out in a row. Used for the autoregressive token
   strip (probability, chain rule) and per-symbol code lengths (information
   theory, coding). */

.token-strip,
.code-strip {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin: 0 0 .6rem;
}

.token-cell {
  padding: .3rem .55rem;
  border: 1px solid var(--line, #e2e2e2);
  border-radius: 4px;
  font-size: .78rem;
  font-variant-numeric: tabular-nums;
}

.token-cell.conditioned { background: rgba(6, 69, 173, .08); }
.token-cell.current { border-color: #f97316; background: rgba(249, 115, 22, .1); }

.code-cell {
  padding: .3rem .5rem;
  border: 1px solid var(--line, #e2e2e2);
  border-radius: 4px;
  font-size: .74rem;
  font-variant-numeric: tabular-nums;
  line-height: 1.35;
  text-align: center;
}

.code-cell b {
  display: block;
  font-weight: 600;
  color: #0645ad;
}

/* ------------------------------------------------------------ field plots */
/* Scalar/vector field figures drawn by the Chart2D extensions in
   js/calc-engine.js (heat, contour, quiver). */

/* Paired canvases sit side by side and want to be shorter than the 300px
   default that .topic-demo canvas sets. */
.topic-demo-dual canvas { height: 210px; }

.field-legend {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin: .1rem 0 .5rem;
  font-size: .72rem;
  color: var(--muted);
}

.field-legend .ramp {
  flex: 1;
  height: 9px;
  border-radius: 3px;
  border: 1px solid var(--line, #e2e2e2);
  /* Matches Calc.diverging() in js/calc-engine.js: blue (−) → white → red (+). */
  background: linear-gradient(to right,
    rgb(45, 125, 255), rgb(150, 190, 255), #fff, rgb(255, 180, 150), rgb(255, 105, 65));
}