/* Reasoning demos: flat, sharp-cornered, page palette. No shadows or gradients.
 * Motion only during a reader-started replay: short colour and opacity
 * transitions (at most 300 ms), removed under prefers-reduced-motion. */
.reasoning-demo {
  --rd-warm: #9a5a3c;
  --rd-kept: #56615b;
  --rd-faint: #aab3ad;
  --rd-rule: #e8ece7;
  margin-top: 18px;
  padding: 27px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  font-size: 14px;
  line-height: 1.65;
}
.reasoning-demo [hidden] { display: none !important; }
.reasoning-demo *, .reasoning-demo *::before { border-radius: 0; }
.reasoning-demo .rd-heading { margin-bottom: 22px; }
.reasoning-demo .rd-heading h3 { margin: 6px 0 10px; }
.reasoning-demo .rd-heading p { margin: 0; max-width: 760px; }
.reasoning-demo h4 { margin: 0 0 8px; font: 400 18px/1.4 Georgia, serif; color: var(--ink); }
.reasoning-demo h5 { margin: 0 0 6px; font-size: 12px; font-weight: 600; line-height: 1.45; color: var(--muted); }
.reasoning-demo .rd-keep-case { text-transform: none; letter-spacing: .02em; }
.reasoning-demo .rd-small-label { display: block; margin: 0 0 6px; color: var(--muted); font-size: 10.5px; font-weight: 600; letter-spacing: .08em; line-height: 1.5; text-transform: uppercase; }
.reasoning-demo .rd-footnote { margin: 14px 0 0; color: var(--muted); font-size: 12px; line-height: 1.7; max-width: 820px; }
.reasoning-demo .rd-control-help { color: var(--muted); font-size: 12px; line-height: 1.5; }
.reasoning-demo .rd-controls { display: flex; align-items: center; flex-wrap: wrap; gap: 10px 14px; margin: 0 0 18px; }
.reasoning-demo button {
  min-height: 36px; margin: 0; padding: 6px 11px;
  border: 1px solid #bbc8bf; border-radius: 0; background: #fff; color: var(--ink);
  font: inherit; font-size: 13px; line-height: 1.3; cursor: pointer;
}
.reasoning-demo button:hover { background: var(--wash); }
.reasoning-demo button[aria-pressed="true"] { border-color: var(--accent); background: var(--accent); color: #fff; }
.reasoning-demo button:disabled { cursor: default; color: #a3aba6; background: #f6f7f5; border-color: var(--line); }
.reasoning-demo button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.reasoning-demo .rd-choice-group { display: flex; flex-wrap: wrap; gap: 7px; margin: 0; padding: 0; border: 0; min-width: 0; }
.reasoning-demo .rd-choice-group legend { width: 100%; margin: 0 0 7px; padding: 0; color: var(--muted); font-size: 12px; }
.reasoning-demo .rd-status { margin: 14px 0 0; font-size: 13.5px; }
.reasoning-demo code { font: 11.5px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--muted); }

/* ContraSolver: prompt, graph, editable judgments, pass log. */
.reasoning-demo .cs-prompt-text { margin: 0 0 10px; font: 400 16px/1.5 Georgia, serif; }
.reasoning-demo .cs-responses { display: grid; gap: 4px; margin: 0; padding: 0; list-style: none; font-size: 13.5px; }
.reasoning-demo .cs-responses li { display: grid; grid-template-columns: 22px minmax(0, 1fr); gap: 10px; align-items: baseline; }
.reasoning-demo .cs-letter { display: inline-block; width: 20px; border: 1px solid var(--ink); font-size: 11px; font-weight: 600; line-height: 18px; text-align: center; }
.reasoning-demo .cs-workspace { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: 32px; align-items: start; margin-top: 22px; padding-top: 22px; border-top: 1px solid var(--line); }
.reasoning-demo .cs-figure { margin: 0; }
.reasoning-demo .cs-graph { display: block; width: 100%; max-width: 420px; height: auto; margin: 0 auto; }
.reasoning-demo .cs-line { fill: none; stroke: var(--rd-kept); stroke-width: 1.6; }
.reasoning-demo .cs-hit { fill: none; stroke: transparent; stroke-width: 16; pointer-events: none; }
.reasoning-demo .cs-graph.is-interactive .cs-hit { pointer-events: stroke; cursor: pointer; }
.reasoning-demo .cs-edge.is-heuristic .cs-line { stroke: var(--accent); stroke-width: 3.2; }
.reasoning-demo .cs-edge.is-contradictory .cs-line { stroke: var(--rd-warm); stroke-width: 2.2; stroke-dasharray: 7 4; }
.reasoning-demo .cs-edge.is-implied .cs-line { stroke: var(--rd-faint); stroke-width: 1.3; stroke-dasharray: 2 4; }
.reasoning-demo .cs-arrowhead { fill: var(--rd-kept); }
.reasoning-demo .cs-arrowhead.is-heuristic { fill: var(--accent); }
.reasoning-demo .cs-arrowhead.is-contradictory { fill: var(--rd-warm); }
.reasoning-demo .cs-arrowhead.is-implied { fill: var(--rd-faint); }
.reasoning-demo .cs-label rect { fill: #fff; }
.reasoning-demo .cs-label text { fill: var(--muted); font: 14.5px -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-variant-numeric: tabular-nums; text-anchor: middle; }
.reasoning-demo .cs-label.is-heuristic text { fill: var(--accent); font-weight: 700; }
.reasoning-demo .cs-label.is-contradictory text { fill: var(--rd-warm); font-weight: 700; }
.reasoning-demo .cs-label.is-implied text { fill: #8c958f; }
.reasoning-demo .cs-node rect { fill: #fff; stroke: var(--ink); stroke-width: 1.3; }
.reasoning-demo .cs-node text { fill: var(--ink); font: 600 17px -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; text-anchor: middle; }
.reasoning-demo .cs-legend { display: flex; flex-wrap: wrap; gap: 4px 16px; margin-top: 10px; color: var(--muted); font-size: 12px; }
.reasoning-demo .cs-legend i, .reasoning-demo .cs-swatch { display: inline-block; width: 22px; height: 0; margin-right: 6px; vertical-align: middle; border-top: 2px solid var(--rd-kept); }
.reasoning-demo .is-heuristic > i, .reasoning-demo .cs-row.is-heuristic .cs-swatch { border-top: 3px solid var(--accent); }
.reasoning-demo .is-contradictory > i, .reasoning-demo .cs-row.is-contradictory .cs-swatch { border-top: 2px dashed var(--rd-warm); }
.reasoning-demo .is-implied > i, .reasoning-demo .cs-row.is-implied .cs-swatch { border-top: 2px dotted var(--rd-faint); }
.reasoning-demo .cs-legend-note { width: 100%; }
.reasoning-demo .cs-result { display: grid; gap: 8px; margin: 18px 0 0; padding-top: 14px; border-top: 1px solid var(--line); }
.reasoning-demo .cs-result div { display: grid; grid-template-columns: minmax(0, 11.5rem) minmax(0, 1fr); gap: 12px; align-items: baseline; }
.reasoning-demo .cs-result dt { color: var(--muted); font-size: 12px; }
.reasoning-demo .cs-result dd { margin: 0; font-size: 14px; font-weight: 600; }
.reasoning-demo .cs-result .is-pairs dd { color: var(--accent); }
.reasoning-demo .cs-result .is-contradictions dd { color: var(--rd-warm); }
.reasoning-demo .cs-edges-head, .reasoning-demo .cs-row { display: grid; grid-template-columns: 22px 4.9rem 7.6rem minmax(0, 1fr); gap: 10px; align-items: center; }
.reasoning-demo .cs-edges-head { margin: 0 0 4px; color: var(--muted); font-size: 11px; font-weight: 600; }
.reasoning-demo .cs-edge-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.reasoning-demo .cs-row { min-height: 42px; padding: 3px 0; border-bottom: 1px solid var(--rd-rule); font-size: 13px; }
.reasoning-demo .cs-swatch { margin: 0; width: 22px; }
.reasoning-demo .cs-judgment { font-variant-numeric: tabular-nums; }
.reasoning-demo .cs-flip { width: 100%; padding: 6px 4px; text-align: center; }
.reasoning-demo .cs-weight { display: inline-flex; align-items: center; }
.reasoning-demo .cs-weight button { width: 34px; min-height: 34px; padding: 0; font-size: 15px; }
.reasoning-demo .cs-weight output { display: inline-block; min-width: 3.1em; text-align: center; font-variant-numeric: tabular-nums; }
.reasoning-demo .cs-outcome { color: var(--muted); font-size: 12.5px; line-height: 1.4; }
.reasoning-demo .cs-row.is-heuristic .cs-outcome { color: var(--accent); font-weight: 600; }
.reasoning-demo .cs-row.is-contradictory .cs-outcome { color: var(--rd-warm); font-weight: 600; }
.reasoning-demo .cs-reset { margin: 14px 0 0; }
.reasoning-demo .cs-readout { margin-top: 26px; padding-top: 18px; border-top: 1px solid var(--line); }
.reasoning-demo .cs-log { margin: 0; padding: 0; list-style: none; }
.reasoning-demo .cs-log li { display: grid; grid-template-columns: 4.4rem minmax(0, 1fr); column-gap: 14px; padding: 7px 0; border-bottom: 1px solid var(--rd-rule); font-size: 13.5px; }
.reasoning-demo .cs-log strong { grid-row: 1 / span 2; font-weight: 600; }
.reasoning-demo .cs-log span { grid-column: 2; }

/* Measured before/after rows shared by both demos (Table 4; Table 2). */
.reasoning-demo .rd-measured { margin: 30px 0 0; padding-top: 20px; border-top: 1px solid var(--line); }
.reasoning-demo .rd-measured figcaption p { margin: 0; max-width: 760px; color: var(--muted); font-size: 13px; }
.reasoning-demo .rd-dumbbell-legend { display: flex; flex-wrap: wrap; gap: 4px 18px; margin: 12px 0 4px; color: var(--muted); font-size: 12px; }
.reasoning-demo .rd-dumbbell-group { margin-top: 10px; }
.reasoning-demo .rd-dumbbell-group h5 { margin-bottom: 2px; }
.reasoning-demo .rd-dumbbell-row { display: grid; grid-template-columns: 7.5rem minmax(0, 1fr) 7.6rem; gap: 14px; align-items: center; min-height: 26px; font-size: 12.5px; }
.reasoning-demo .rd-dumbbell-track, .reasoning-demo .rd-axis { position: relative; height: 18px; }
.reasoning-demo .rd-dumbbell-track::before { content: ""; position: absolute; left: 0; right: 0; top: 50%; border-top: 1px solid var(--line); }
.reasoning-demo .rd-dumbbell-span { position: absolute; top: calc(50% - 1px); border-top: 2px solid #9aa59f; }
.reasoning-demo .rd-dot { position: absolute; top: 50%; width: 10px; height: 10px; margin: -5px 0 0 -5px; box-sizing: border-box; border: 1.5px solid var(--ink); background: #fff; }
.reasoning-demo .rd-dot.is-after { border-color: var(--accent); background: var(--accent); }
.reasoning-demo .rd-dumbbell-legend .rd-dot { position: relative; display: inline-block; top: 1px; margin: 0 6px 0 0; }
.reasoning-demo .rd-dumbbell-values { text-align: right; font-variant-numeric: tabular-nums; }
.reasoning-demo .rd-axis span { position: absolute; top: 0; transform: translateX(-50%); color: var(--muted); font-size: 10.5px; line-height: 18px; }
.reasoning-demo .rd-axis span:first-child { transform: none; }
.reasoning-demo .rd-axis span:last-child:not(:first-child) { transform: translateX(-100%); }

/* Atomic to Composite: worked task, all-split results, error locations. */
.reasoning-demo .ac-task { padding-top: 18px; border-top: 1px solid var(--line); }
.reasoning-demo .ac-question { margin: 0 0 16px; font: 400 19px/1.45 Georgia, serif; }
.reasoning-demo .ac-sources { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.reasoning-demo .ac-sources > div { padding-left: 12px; border-left: 2px solid var(--line); }
.reasoning-demo .ac-sources p { margin: 0; font-size: 13.5px; }
.reasoning-demo .ac-empty { color: var(--muted); font-style: italic; }
.reasoning-demo .ac-trace-title { margin-top: 18px; }
.reasoning-demo .ac-trace { margin: 0; padding: 0; list-style: none; counter-reset: hop; border-top: 1px solid var(--line); }
.reasoning-demo .ac-trace li { counter-increment: hop; display: grid; grid-template-columns: 1.4rem 4.6rem minmax(0, 1fr); gap: 8px; align-items: baseline; padding: 7px 0; border-bottom: 1px solid var(--rd-rule); font-size: 14px; }
.reasoning-demo .ac-trace li::before { content: counter(hop); color: var(--muted); font-size: 12px; font-variant-numeric: tabular-nums; }
.reasoning-demo .ac-source { font-size: 10.5px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.reasoning-demo [data-source="memory"] .ac-source { color: var(--accent); }
.reasoning-demo .ac-relation { color: var(--muted); font-style: italic; }
.reasoning-demo .ac-answer { display: flex; align-items: baseline; gap: 14px; margin: 12px 0 0; }
.reasoning-demo .ac-answer > span { color: var(--muted); font-size: 12px; }
.reasoning-demo .ac-answer strong { color: var(--accent); font: 400 17px/1.4 Georgia, serif; }
.reasoning-demo .ac-legend { display: flex; flex-wrap: wrap; gap: 4px 18px; margin: 12px 0 2px; color: var(--muted); font-size: 12px; }
.reasoning-demo .ac-legend i { display: inline-block; width: 14px; height: 10px; margin-right: 6px; vertical-align: -1px; background: var(--accent); }
.reasoning-demo .ac-legend .is-composite i, .reasoning-demo .ac-bar-row.is-composite i { background: #a3ada7; }
.reasoning-demo .ac-split { padding: 12px 0 10px; border-bottom: 1px solid var(--rd-rule); }
.reasoning-demo .ac-split-head { margin: 0 0 6px; font-size: 13px; }
.reasoning-demo .ac-split-head span { color: var(--muted); }
.reasoning-demo .ac-split-head code { margin-left: 4px; }
.reasoning-demo .ac-bar-row { display: grid; grid-template-columns: 7.2rem minmax(0, 1fr) 3.4rem; gap: 10px; align-items: center; margin: 3px 0; font-size: 12.5px; }
.reasoning-demo .ac-bar-track { height: 12px; background: var(--wash); }
.reasoning-demo .ac-bar-track i { display: block; height: 100%; background: var(--accent); }
.reasoning-demo .ac-bar-row strong { text-align: right; font-variant-numeric: tabular-nums; font-weight: 600; }
.reasoning-demo .ac-gap { margin: 4px 0 0 calc(7.2rem + 10px); color: var(--muted); font-size: 12.5px; }
.reasoning-demo .ac-gap.is-reversed { color: var(--ink); font-weight: 600; }

@media (max-width: 860px) {
  .reasoning-demo .cs-workspace { grid-template-columns: minmax(0, 1fr); gap: 24px; }
}
@media (max-width: 700px) {
  .reasoning-demo { padding: 20px 16px; }
  .reasoning-demo .ac-sources { grid-template-columns: minmax(0, 1fr); gap: 12px; }
}
@media (max-width: 520px) {
  .reasoning-demo .cs-edges-head { display: none; }
  .reasoning-demo .cs-row { grid-template-columns: 16px 4.6rem minmax(0, 1fr); gap: 0 10px; padding: 5px 0 6px; }
  .reasoning-demo .cs-outcome { font-size: 12px; }
  .reasoning-demo .cs-swatch { width: 16px; }
  .reasoning-demo .cs-outcome { grid-column: 2 / -1; }
  .reasoning-demo .cs-result div { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .reasoning-demo .cs-log li { grid-template-columns: minmax(0, 1fr); }
  .reasoning-demo .cs-log strong { grid-row: auto; }
  .reasoning-demo .cs-log span { grid-column: 1; }
  .reasoning-demo .rd-dumbbell-row { grid-template-columns: minmax(0, 1fr) auto; gap: 0 10px; padding: 3px 0; }
  .reasoning-demo .rd-dumbbell-track { grid-column: 1 / -1; grid-row: 2; }
  .reasoning-demo .rd-axis-row > span:not(.rd-axis) { display: none; }
  .reasoning-demo .rd-axis { grid-column: 1 / -1; }
  .reasoning-demo .ac-bar-row { grid-template-columns: 5.7rem minmax(0, 1fr) 2.9rem; gap: 8px; font-size: 12px; }
  .reasoning-demo .ac-gap { margin-left: calc(5.7rem + 8px); }
  .reasoning-demo .ac-split-head code { display: block; margin: 2px 0 0; }
  .reasoning-demo .rd-dumbbell-row { padding: 2px 0 6px; }
}
@media (max-width: 360px) {
  .reasoning-demo .ac-trace li { grid-template-columns: 1.1rem minmax(0, 1fr); }
  .reasoning-demo .ac-trace .ac-hop { grid-column: 2; }
}

/* Top-level eyebrow matches the other demo families. */
.reasoning-demo .rd-heading .rd-eyebrow { color: var(--accent); font-size: 10px; letter-spacing: .1em; }

/* Visually hidden text for assistive technology. */
.reasoning-demo .rd-visually-hidden { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }

/* Evidence blocks: the measured chart starts directly under the heading. */
.reasoning-demo.rd-evidence > .rd-measured:first-of-type { margin-top: 0; padding-top: 0; border-top: 0; }

/* Reader-started replay: Play, Pause, Step, Reset and a one-line status. */
.reasoning-demo .rd-player { gap: 6px; margin: 0 0 8px; }
.reasoning-demo .rd-player button { min-width: 64px; }
.reasoning-demo .rd-player-status { min-height: 1.7em; margin: 0 0 14px; color: var(--ink); font-size: 13px; line-height: 1.55; }
.reasoning-demo .rd-player-status:empty { margin-bottom: 6px; }

/* ContraSolver replay: unexamined edges, the decision being made, the log sentence. */
.reasoning-demo .cs-edge.is-pending .cs-line { stroke: #c9d0cb; stroke-width: 1.2; stroke-dasharray: 1 5; }
.reasoning-demo .cs-arrowhead.is-pending { fill: #c9d0cb; }
.reasoning-demo .cs-label.is-pending text { fill: #9aa39e; }
.reasoning-demo .cs-edge.is-current .cs-line { stroke-width: 4.2; }
.reasoning-demo .cs-edge.is-current.is-pending .cs-line { stroke: var(--ink); stroke-dasharray: none; stroke-width: 2.4; }
.reasoning-demo .cs-label.is-current rect { stroke: var(--ink); stroke-width: 1.2; }
.reasoning-demo .cs-label.is-current text { fill: var(--ink); font-weight: 700; }
.reasoning-demo .cs-row.is-pending .cs-outcome { color: #8c958f; font-style: italic; }
.reasoning-demo .cs-row.is-pending .cs-swatch, .reasoning-demo .cs-legend .is-pending > i { border-top: 2px dotted #c9d0cb; }
/* The legend names unexamined edges only while a replay shows them. */
.reasoning-demo:not(.is-replaying) .cs-legend .is-pending { display: none; }
.reasoning-demo .cs-row.is-current { background: var(--wash); }
.reasoning-demo .cs-result-region.is-partial dd { color: var(--muted); }
.reasoning-demo .cs-log span.is-current { background: var(--wash); box-shadow: none; outline: 1px solid var(--line); }
.reasoning-demo .cs-log .is-future { color: #a3aba6; }
.reasoning-demo .cs-line, .reasoning-demo .cs-label text, .reasoning-demo .cs-row, .reasoning-demo .cs-log span { transition: stroke .25s ease, stroke-width .25s ease, fill .25s ease, color .25s ease, background-color .25s ease; }

/* Atomic replay: the fact each hop reads, hops not reached yet, the pending answer. */
.reasoning-demo .ac-fact { transition: background-color .25s ease, color .25s ease; }
.reasoning-demo .ac-fact.is-used { color: var(--ink); text-decoration: underline; text-decoration-color: #b9c4bd; text-underline-offset: 3px; }
.reasoning-demo .ac-fact.is-current { background: var(--wash); color: var(--ink); outline: 1px solid var(--accent); text-decoration: none; }
.reasoning-demo [data-source-panel] { transition: border-color .25s ease; }
.reasoning-demo [data-source-panel].is-current { border-left-color: var(--accent); }
.reasoning-demo .ac-trace li { transition: background-color .25s ease, opacity .25s ease; }
.reasoning-demo .ac-trace li.is-future > span { visibility: hidden; }
.reasoning-demo .ac-trace li.is-current { background: var(--wash); }
.reasoning-demo .ac-answer strong.is-pending { color: var(--muted); }

@media (prefers-reduced-motion: reduce) {
  .reasoning-demo *, .reasoning-demo *::before, .reasoning-demo *::after { transition: none !important; }
}