/* CAD Intuition Gym — workbench-calm product UI.
   Register (per _planning/design-agent-priorities.md Priority 0):
   product UI mirroring CAD-software chrome — quiet, dense, familiar controls.
   Accent color is scarce; the loud moments belong to the consequence. */

:root {
  --chrome: #eceff3;
  --panel: #ffffff;
  --panel-2: #f6f8fa;
  --border: #d6dde5;
  --border-strong: #b7c2ce;
  --ink: #1d2833;
  --muted: #5c6b7a;
  --faint: #8a97a5;
  --accent: #1a66d6;
  --accent-deep: #1554b4;
  --accent-soft: #e8f0fc;
  --good: #0d7a48;
  --good-soft: #e3f3ea;
  --bad: #c0372f;
  --bad-soft: #fbeae8;
  --warn: #91650e;
  --warn-soft: #faf1dc;
  --grid: #e9eef3;
  --scope: #6c55c8;
  --scope-soft: #efeafb;
  --radius: 8px;
  --ui: 'Sora', system-ui, sans-serif;
  --serif: 'Source Serif 4', georgia, serif;
  --mono: 'JetBrains Mono', ui-monospace, menlo, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--chrome);
  color: var(--ink);
  font-family: var(--ui);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

button { font-family: inherit; }

.kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0;
}

.linklike {
  background: none;
  border: 0;
  padding: 0;
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 2px;
  cursor: pointer;
  font-size: 12.5px;
}
.linklike:hover { color: var(--ink); }

/* ------------------------------------------------------------------ home */

.home { max-width: 720px; margin: 0 auto; padding: 56px 24px 64px; }

.home h1 {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(28px, 5vw, 40px);
  line-height: 1.15;
  margin: 10px 0 18px;
}

.lede {
  font-family: var(--serif);
  font-size: 17.5px;
  line-height: 1.65;
  margin: 0 0 14px;
  max-width: 62ch;
}

.sim-note {
  font-size: 13px;
  color: var(--muted);
  max-width: 62ch;
  margin: 0;
}

.section-label {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 44px 0 12px;
}

.ex-list {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.ex-row {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: background-color 0.12s;
}
.ex-row:last-child { border-bottom: 0; }
a.ex-row:hover { background: var(--panel-2); }
.ex-row.is-locked { opacity: 0.55; }

.ex-num { font-family: var(--mono); font-size: 13px; color: var(--faint); }
.ex-row-text { flex: 1; min-width: 0; }
.ex-row-title { display: block; font-weight: 600; font-size: 14.5px; }
.ex-row-tag { display: block; font-size: 13px; color: var(--muted); margin-top: 1px; }
.ex-status { font-family: var(--mono); font-size: 12px; color: var(--faint); white-space: nowrap; }
.ex-status.is-go { color: var(--accent); }
.ex-status.is-done { color: var(--good); }

.home-foot {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  margin-top: 26px;
  font-size: 12px;
  color: var(--faint);
}

.recap { margin-top: 44px; }
.recap .section-label { margin-top: 0; }

.recap-lede {
  font-size: 13px;
  line-height: 1.55;
  color: var(--muted);
  margin: 0 0 12px;
}

.recap-list {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.recap-row {
  display: flex;
  align-items: baseline;
  gap: 18px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
}
.recap-row:last-child { border-bottom: 0; }

.recap-text { flex: 1; min-width: 0; }

.recap-line {
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  margin: 0;
}

.recap-flip {
  font-size: 12.5px;
  font-style: italic;
  color: var(--muted);
  margin: 3px 0 0;
}

/* ---------------------------------------------------------------- player */

.player { max-width: 1220px; margin: 0 auto; padding: 18px 20px 48px; }

.ex-header-row {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 4px 2px 0;
  flex-wrap: wrap;
}
.backlink {
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
}
.backlink:hover { color: var(--ink); text-decoration: underline; text-underline-offset: 2px; }
.ex-title { font-weight: 600; flex: 1; }

.stepper {
  display: flex;
  gap: 4px;
  list-style: none;
  margin: 10px 0 14px;
  padding: 0;
  flex-wrap: wrap;
}
.step-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 12px 5px 6px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: none;
  font-size: 12.5px;
  color: var(--muted);
}
button.step-btn { cursor: pointer; transition: border-color 0.12s, color 0.12s; }
button.step-btn:hover { border-color: var(--border-strong); color: var(--ink); }
.step.is-current .step-btn {
  background: var(--panel);
  border-color: var(--border-strong);
  color: var(--ink);
  font-weight: 600;
}
.step-dot {
  display: inline-grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--chrome);
  border: 1px solid var(--border-strong);
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--muted);
}
.step.is-current .step-dot { background: var(--accent); border-color: var(--accent); color: #fff; }
.step.is-done .step-dot { background: var(--ink); border-color: var(--ink); color: #fff; }

.ex-body {
  display: grid;
  grid-template-columns: 216px minmax(0, 1fr) 372px;
  gap: 14px;
  align-items: start;
}

/* ---- features panel (the Onshape furniture) ---- */

.features-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.features-panel summary {
  list-style: none;
  cursor: pointer;
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
}
.features-panel summary::-webkit-details-marker { display: none; }
.features-panel[open] summary { border-bottom: 1px solid var(--border); }
.panel-kicker {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.panel-sub { font-size: 11px; color: var(--faint); }

.features-body { padding: 6px; }
.feat {
  display: flex;
  gap: 9px;
  padding: 8px 9px;
  border-radius: 6px;
  align-items: flex-start;
}
.feat.is-active { background: var(--accent-soft); }
.feat-dot {
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--faint);
  margin-top: 5px;
  flex: none;
}
.feat.is-active .feat-dot { background: var(--accent); }
.feat-text { min-width: 0; }
.feat-label { display: block; font-size: 12.5px; font-weight: 500; }
.feat-sub { display: block; font-size: 11.5px; color: var(--muted); margin-top: 1px; }

/* ---- viewport ---- */

.viewport-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px;
}
.viewport { display: flex; flex-direction: column; gap: 8px; }

.scene {
  display: block;
  width: 100%;
  height: auto;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
}

.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.pane { margin: 0; display: flex; flex-direction: column; gap: 6px; min-width: 0; }
.pane-cap {
  font-size: 11.5px;
  color: var(--muted);
  display: flex;
  gap: 7px;
  align-items: baseline;
}
.pane-key {
  font-family: var(--mono);
  font-size: 10.5px;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  padding: 0 5px;
  color: var(--ink);
  flex: none;
}

.outcome-chip {
  min-height: 26px;
  font-family: var(--mono);
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 6px;
  color: var(--muted);
}
.outcome-chip.is-on.tone-idle { background: var(--panel-2); color: var(--muted); }
.outcome-chip.is-on.tone-good { background: var(--good-soft); color: var(--good); }
.outcome-chip.is-on.tone-warn { background: var(--warn-soft); color: var(--warn); }
.outcome-chip.is-on.tone-bad { background: var(--bad-soft); color: var(--bad); }

/* ---- rail ---- */

.rail-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
}
.rail { display: flex; flex-direction: column; gap: 14px; }

.rail-head { font-family: var(--serif); font-size: 22px; line-height: 1.2; margin: 0; }
.prose { font-family: var(--serif); font-size: 15.5px; line-height: 1.6; margin: 0; }
.fine { font-size: 12px; color: var(--faint); margin: 0; }

.intent-card {
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--panel-2);
  padding: 13px 14px;
  display: flex;
  flex-direction: column;
  gap: 11px;
}
.intent-k {
  display: block;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}
.intent-v {
  display: block;
  font-family: var(--serif);
  font-size: 14.5px;
  line-height: 1.45;
  margin-top: 2px;
}

.options { display: flex; flex-direction: column; gap: 8px; }
.option {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  text-align: left;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--panel);
  cursor: pointer;
  position: relative;
  transition: border-color 0.12s, background-color 0.12s;
}
.option:hover { border-color: var(--border-strong); }
.option.is-selected {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: inset 0 0 0 1px var(--accent);
}
.option-key {
  font-family: var(--mono);
  font-size: 11px;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  padding: 1px 6px;
  margin-top: 1px;
  flex: none;
}
.option.is-selected .option-key { background: var(--accent); border-color: var(--accent); color: #fff; }
.option-text { min-width: 0; }
.option-label { display: block; font-weight: 600; font-size: 13.5px; padding-right: 64px; }
.option-sub { display: block; font-size: 12.5px; color: var(--muted); margin-top: 2px; }
.guess-tag {
  position: absolute;
  top: 9px;
  right: 11px;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}

.btn {
  font-weight: 600;
  font-size: 13.5px;
  padding: 10px 16px;
  border-radius: 6px;
  border: 1px solid var(--border-strong);
  background: var(--panel);
  color: var(--ink);
  cursor: pointer;
  transition: border-color 0.12s, background-color 0.12s, color 0.12s;
  align-self: flex-start;
}
.btn:hover { border-color: var(--ink); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-deep); border-color: var(--accent-deep); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn:disabled:hover { border-color: var(--accent); background: var(--accent); }
.btn.ghost {
  background: none;
  border-color: var(--border);
  color: var(--muted);
  font-weight: 500;
  font-size: 12.5px;
  padding: 7px 12px;
}
.btn.ghost:hover { color: var(--ink); border-color: var(--border-strong); }
.btn.ghost[aria-pressed="true"] {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

.unit-toggle {
  position: fixed;
  top: 12px;
  right: 12px;
  z-index: 50;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 6px 11px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: var(--panel);
  color: var(--muted);
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  transition: border-color 0.12s, color 0.12s, background-color 0.12s;
}
.unit-toggle:hover { color: var(--ink); border-color: var(--accent); }
.unit-toggle::before { content: 'units: '; color: var(--faint); font-weight: 500; }

.change-card {
  border: 1px solid #e6d9b4;
  background: #fbf6e7;
  border-radius: 6px;
  padding: 12px 14px;
}
.change-kicker {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--warn);
}
.change-quote { font-family: var(--serif); font-size: 15px; line-height: 1.5; margin: 6px 0 0; }

.slider-block { display: flex; flex-direction: column; gap: 6px; }
.slider-head { display: flex; justify-content: space-between; align-items: baseline; }
.slider-label { font-size: 12.5px; font-weight: 600; }
.slider-val { font-family: var(--mono); font-size: 13px; color: var(--accent); }
.slider { width: 100%; accent-color: var(--accent); margin: 0; }

.outcome-note { font-size: 13px; line-height: 1.5; margin: 0; color: var(--muted); min-height: 3.9em; }
.outcome-note.tone-good { color: var(--good); }
.outcome-note.tone-warn { color: var(--warn); }
.outcome-note.tone-bad { color: var(--bad); }

.viewrow { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.viewrow-label {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--faint);
}
.segmented {
  display: inline-flex;
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  overflow: hidden;
}
.segmented.is-disabled { opacity: 0.55; }
.seg {
  font-size: 12px;
  padding: 6px 11px;
  background: var(--panel);
  border: 0;
  cursor: pointer;
  color: var(--muted);
  transition: background-color 0.12s, color 0.12s;
}
.seg + .seg { border-left: 1px solid var(--border); }
.seg:hover:not(:disabled):not(.is-on) { color: var(--ink); background: var(--panel-2); }
.seg.is-on { background: var(--ink); color: #fff; }
.seg:disabled { cursor: default; }

.pred-chip {
  font-size: 13px;
  line-height: 1.5;
  margin: 0;
  padding: 10px 12px;
  border-radius: 6px;
  border: 1px solid var(--border);
}
.pred-chip.is-right { background: var(--good-soft); border-color: #bfe0cd; color: var(--good); }
.pred-chip.is-wrong { background: var(--warn-soft); border-color: #e7d4a4; color: var(--warn); }

.takeaway {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.4;
  margin: 0;
}
.term-note {
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--muted);
  margin: 0;
  padding: 9px 12px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
}
.rule { border: 0; border-top: 1px solid var(--border); margin: 6px 0; }
.flip-head { font-family: var(--serif); font-size: 18px; margin: 0; }
.moral { font-family: var(--serif); font-size: 15px; line-height: 1.55; margin: 0; }

/* ---- scene (SVG) vocabulary ---- */

.grid-line { fill: none; stroke: var(--grid); stroke-width: 1; }
.hatch-line { stroke: #cdd6df; stroke-width: 2.5; }
.wall-face { stroke: #8593a2; stroke-width: 2; }

.part { fill: #eef4fb; stroke: #31414f; stroke-width: 1.6; }
.part.is-loose { stroke: #2e77d0; }   /* Onshape's vocabulary: blue = still free to move */
.part.alt { fill: #e3edf9; }
.ghost { fill: none; stroke: var(--faint); stroke-width: 1.2; stroke-dasharray: 5 5; }
.ghost-label, .scenelabel {
  font-family: var(--mono);
  font-size: 10px;
  fill: var(--faint);
  paint-order: stroke;
  stroke: #fff;
  stroke-width: 3;
}

.hole { fill: #fff; stroke: #31414f; stroke-width: 1.6; }
.hole.is-good { stroke: var(--good); stroke-width: 2.2; }
.hole.is-bad { stroke: var(--bad); stroke-width: 2.2; fill: #fdf1f0; }

.pull-line { stroke: #55677a; stroke-width: 1.7; }
.offline { stroke: var(--bad); stroke-width: 1.2; stroke-dasharray: 4 3; }
.gap-bad { fill: rgba(192, 55, 47, 0.14); stroke: var(--bad); stroke-width: 1.1; stroke-dasharray: 4 3; }
.switch-part { fill: #d7e0ea; stroke: #31414f; stroke-width: 1.6; }
.switch-mark { stroke: #55677a; stroke-width: 1.2; }
.scenelabel.bad { fill: var(--bad); }
.scenelabel.accent { fill: var(--accent); }

.intent-ring { fill: none; stroke: var(--accent); stroke-width: 1.2; stroke-dasharray: 3 3; }
.intent-line { stroke: var(--accent); stroke-width: 1; stroke-dasharray: 3 3; }
.intent-label {
  font-family: var(--mono);
  font-size: 10px;
  fill: var(--accent);
  paint-order: stroke;
  stroke: #fff;
  stroke-width: 3;
}

/* E5 vocabulary: the in-scene feature tree and the violet "edit scope" —
   what this edit session can touch. Violet on purpose: it must read as its
   own idea, not intent-blue and not consequence-red. */
.ftree-box { fill: var(--panel-2); stroke: var(--border-strong); stroke-width: 1; }
.ftree-text { font-family: var(--mono); font-size: 10px; fill: var(--muted); }
.ftree-dot { fill: var(--faint); }
.ftree-row.is-active .ftree-box { fill: var(--scope-soft); stroke: var(--scope); stroke-width: 1.4; }
.ftree-row.is-active .ftree-text { fill: var(--scope); font-weight: 600; }
.ftree-row.is-active .ftree-dot { fill: var(--scope); }
.ftree-row.is-error .ftree-box { fill: var(--bad-soft); stroke: var(--bad); stroke-width: 1.4; }
.ftree-row.is-error .ftree-text { fill: var(--bad); font-weight: 600; }
.ftree-row.is-error .ftree-dot { fill: var(--bad); }
.ftree-glyph { font-family: var(--mono); font-size: 12px; font-weight: 700; fill: var(--bad); }
.edit-scope { fill: rgba(108, 85, 200, 0.07); stroke: var(--scope); stroke-width: 1.1; stroke-dasharray: 6 4; }
.scope-label {
  font-family: var(--mono);
  font-size: 10px;
  fill: var(--scope);
  paint-order: stroke;
  stroke: #fff;
  stroke-width: 3;
}
.leader { fill: none; stroke: var(--scope); stroke-width: 1.1; stroke-dasharray: 6 4; }
.intent-outline { fill: none; stroke: var(--accent); stroke-width: 1.1; stroke-dasharray: 3 3; }

.centerline { stroke: #7b8ba0; stroke-width: 1; stroke-dasharray: 14 4 3 4; }
.centerline.bolt-line { stroke: var(--accent); }

.dim .ext { stroke: #98a5b3; stroke-width: 0.9; }
.dim .dimline { stroke: #5f6f7f; stroke-width: 1; }
.dim .arrowhead { fill: #5f6f7f; }
.dimtext {
  font-family: var(--mono);
  font-size: 11px;
  fill: #3c4c5c;
  paint-order: stroke;
  stroke: #fff;
  stroke-width: 3;
}
.dim.anchor .dimline, .dim.anchor .ext { stroke: var(--accent); }
.dim.anchor .arrowhead { fill: var(--accent); }
.dim.anchor .dimtext { fill: var(--accent); }
.dim.live .dimtext { fill: var(--ink); font-weight: 500; }
.dim.bad .dimline, .dim.bad .ext { stroke: var(--bad); }
.dim.bad .arrowhead { fill: var(--bad); }
.dim.bad .dimtext { fill: var(--bad); font-weight: 500; }

/* ------------------------------------------------------------- responsive */

@media (max-width: 980px) {
  .player { padding: 12px 12px 40px; }
  .ex-body { grid-template-columns: 1fr; }
  .viewport-panel { order: 1; }
  .rail-panel { order: 2; }
  .features-panel { order: 3; }
  .compare { grid-template-columns: 1fr; }
  .home { padding: 40px 20px 56px; }
}

@media (max-width: 480px) {
  /* Compare panes render the same 520×300 scene viewBox at a much smaller
     display width than the single-view scene does, so the pre-set SVG label
     sizes end up tighter than elsewhere. Bump just those, just here. */
  .compare .scenelabel,
  .compare .ghost-label,
  .compare .intent-label {
    font-size: 12px;
  }
  .compare .dimtext {
    font-size: 13px;
  }
  /* Tree rows are fixed-width boxes (146px in the viewBox), so this bump is
     capped where the longest row label still fits inside its box. */
  .compare .ftree-text,
  .compare .scope-label {
    font-size: 11px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
    scroll-behavior: auto !important;
  }
}

/* ---- bridge card (the optional real-Onshape postscript) ---- */

.bridge-card {
  border: 1px dashed var(--border-strong);
  background: var(--panel-2);
  border-radius: 6px;
  padding: 13px 14px;
  display: flex;
  flex-direction: column;
  gap: 9px;
  min-width: 0;
}
.bridge-kicker {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}
.bridge-card .prose { font-size: 14px; line-height: 1.55; }
.bridge-link {
  display: inline-block;
  align-self: flex-start;
  text-decoration: none;
}