/* ============================================================
   LLM FIELD MANUAL — design system
   Palantir token set (dark variant) × Apple restraint.
   Palette is locked: #000, #1e2124, #2f3234, #565656,
   #e5e5e5, #9b9b9b, #636363, #fff, #a6f2cc, #2b5945,
   #4e8af7, #ff4136 (+ rgba tints of these only).
   Grid: 4px. Fonts: Alliance No.2 / No.1 / system mono.
   ============================================================ */

@font-face {
  font-family: "Alliance No.2";
  src: url("https://www.palantir.com/fonts/Alliance/AllianceNo2-Regular.woff2") format("woff2");
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Alliance No.2";
  src: url("https://www.palantir.com/fonts/Alliance/AllianceNo2-Bold.woff2") format("woff2");
  font-weight: 700; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Alliance No.1";
  src: url("https://www.palantir.com/fonts/Alliance/AllianceNo1-Regular.woff2") format("woff2");
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: "Alliance No.1";
  src: url("https://www.palantir.com/fonts/Alliance/AllianceNo1-Bold.woff2") format("woff2");
  font-weight: 700; font-style: normal; font-display: swap;
}

:root {
  --bg: #000000;
  --panel: #1e2124;
  --hairline: #2f3234;
  --border-strong: #565656;
  --text: #e5e5e5;
  --text-bright: #ffffff;
  --text-secondary: #9b9b9b;
  --text-muted: #636363;
  --accent: #a6f2cc;
  --accent-deep: #2b5945;
  --accent-10: rgba(166, 242, 204, 0.10);
  --accent-05: rgba(166, 242, 204, 0.05);
  --blue: #4e8af7;
  --blue-10: rgba(78, 138, 247, 0.12);
  --danger: #ff4136;
  --font-display: "Alliance No.2", -apple-system, "SF Pro Display", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-body: "Alliance No.1", -apple-system, "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Menlo", "Cascadia Mono", monospace;
  --max-w: 1240px;
  --ease-expo: cubic-bezier(0.19, 1, 0.22, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }
html:focus-within { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

::selection { background: var(--accent-deep); color: var(--text-bright); }

/* ---------- scrollbar ---------- */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--hairline); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-strong); }

/* ============================================================
   TOP BAR
   ============================================================ */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 900;
  display: flex; align-items: center; gap: 16px;
  height: 56px; padding: 0 24px;
  background: rgba(0, 0, 0, 0.92);
  border-bottom: 1px solid var(--hairline);
}
.topbar .wordmark {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.18em;
  color: var(--text-bright); text-transform: uppercase; text-decoration: none;
  display: flex; align-items: center; gap: 10px; white-space: nowrap;
}
.wordmark .tick { width: 8px; height: 8px; background: var(--accent); display: inline-block; }
.topbar .crumb {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em;
  color: var(--text-muted); text-transform: uppercase; white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis;
}
.topbar .spacer { flex: 1; }
.topbar .bar-link {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--text-secondary); text-decoration: none;
  padding: 8px 12px; border: 1px solid transparent;
  transition: color 0.25s ease-in-out, border-color 0.25s ease-in-out;
  white-space: nowrap;
}
.topbar .bar-link:hover { color: var(--accent); border-color: var(--hairline); }
.topbar .bar-link.primary { border: 1px solid var(--hairline); color: var(--text-bright); }
.topbar .bar-link.primary:hover { background: var(--accent); color: #000; border-color: var(--accent); }

.progress-rail {
  position: fixed; top: 56px; left: 0; right: 0; height: 2px; z-index: 899;
  background: transparent;
}
.progress-rail .progress-fill {
  height: 100%; width: 100%; background: var(--accent);
  transform-origin: 0 50%; transform: scaleX(0);
}

/* ============================================================
   CHAPTER LAYOUT
   ============================================================ */
.shell { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

.chapter-grid {
  display: grid; grid-template-columns: 224px minmax(0, 1fr);
  gap: 64px; align-items: start;
}
@media (max-width: 59.9375em) {
  .chapter-grid { grid-template-columns: minmax(0, 1fr); }
  .side-nav { display: none; }
}

.side-nav {
  position: sticky; top: 96px;
  padding-top: 8px;
  max-height: calc(100vh - 128px); overflow-y: auto;
}
.side-nav .side-label {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--text-muted); margin-bottom: 16px;
}
.side-nav a {
  display: flex; gap: 10px; align-items: baseline;
  font-family: var(--font-mono); font-size: 11.5px; line-height: 1.5;
  letter-spacing: 0.04em; color: var(--text-secondary); text-decoration: none;
  padding: 6px 10px; border-left: 1px solid var(--hairline);
  transition: color 0.25s ease-in-out, border-color 0.25s ease-in-out, background 0.25s ease-in-out;
}
.side-nav a .n { color: var(--text-muted); font-size: 10px; min-width: 24px; }
.side-nav a:hover { color: var(--text-bright); }
.side-nav a.active {
  color: var(--accent); border-left-color: var(--accent);
  background: var(--accent-05);
  animation: flickOn 0.3s steps(1) 1;
}
.side-nav a.active .n { color: var(--accent); }

@keyframes flickOn {
  0% { opacity: 1; } 15% { opacity: 0; } 30% { opacity: 1; }
  45% { opacity: 0; } 60% { opacity: 1; } 75% { opacity: 0; } 90% { opacity: 1; }
}

/* ============================================================
   CHAPTER HEADER
   ============================================================ */
.chapter-hero { padding: 176px 0 96px; position: relative; }
.chapter-hero .ch-index {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.24em;
  color: var(--accent); text-transform: uppercase;
  display: flex; align-items: center; gap: 12px; margin-bottom: 24px;
}
.ch-index::before { content: ""; width: 32px; height: 1px; background: var(--accent); display: inline-block; }
.chapter-hero h1 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(44px, 7vw, 88px); line-height: 1.02;
  letter-spacing: -0.02em; color: var(--text-bright);
  margin-bottom: 28px; max-width: 18ch;
}
.chapter-hero .lede {
  font-size: 19px; line-height: 1.65; color: var(--text-secondary); max-width: 62ch;
}
.chapter-hero .lede strong { color: var(--text); font-weight: 400; }
.ch-meta {
  display: flex; gap: 32px; margin-top: 40px; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--text-muted);
}
.ch-meta span b { color: var(--text-secondary); font-weight: 400; display: block; margin-top: 4px; }

/* ============================================================
   SECTIONS / PROSE
   ============================================================ */
.section { padding: 72px 0; border-top: 1px solid #1e2124; scroll-margin-top: 88px; }
.section:first-of-type { border-top: 0; padding-top: 0; }

.sec-head { display: flex; align-items: baseline; gap: 16px; margin-bottom: 28px; }
.sec-head .sec-num {
  font-family: var(--font-mono); font-size: 12px; color: var(--accent);
  letter-spacing: 0.12em;
}
.sec-head h2 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(26px, 3.2vw, 36px); line-height: 1.15;
  letter-spacing: -0.01em; color: var(--text-bright);
}
.section h3 {
  font-family: var(--font-display); font-weight: 700; font-size: 19px;
  color: var(--text-bright); margin: 40px 0 12px; letter-spacing: 0;
}
.section p { margin-bottom: 16px; max-width: 70ch; color: var(--text); }
.section p.note { color: var(--text-secondary); }
.section ul, .section ol { margin: 0 0 16px 20px; max-width: 68ch; }
.section li { margin-bottom: 8px; color: var(--text); }
.section li::marker { color: var(--accent); }
.section a { color: var(--accent); text-decoration: none; border-bottom: 1px solid var(--accent-deep); transition: color .25s ease-in-out; }
.section a:hover { color: var(--text-bright); }
.section strong { color: var(--text-bright); font-weight: 700; }
.section em { color: var(--text-secondary); }

.term {
  color: var(--text-bright);
  border-bottom: 1px dotted var(--border-strong);
  cursor: help;
}

/* inline code */
code {
  font-family: var(--font-mono); font-size: 0.86em;
  color: var(--accent); background: var(--accent-05);
  padding: 2px 6px; border-radius: 4px;
  border: 1px solid rgba(166, 242, 204, 0.15);
}
pre {
  background: #000; border: 1px solid var(--hairline); border-radius: 4px;
  padding: 20px 24px; overflow-x: auto; margin: 24px 0;
  font-family: var(--font-mono); font-size: 12.5px; line-height: 1.7;
  color: var(--text-secondary);
}
pre code { background: none; border: 0; padding: 0; color: inherit; font-size: inherit; }
pre .c { color: var(--text-muted); } /* comment */
pre .k { color: var(--accent); }     /* keyword  */
pre .v { color: var(--blue); }       /* value    */

/* ============================================================
   EQUATION BLOCKS
   ============================================================ */
.eq {
  margin: 28px 0; padding: 28px 32px;
  background: var(--accent-05);
  border: 1px solid var(--hairline);
  border-left: 2px solid var(--accent);
  border-radius: 4px;
  overflow-x: auto;
  position: relative;
}
.eq .eq-tag {
  position: absolute; top: 10px; right: 14px;
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--text-muted);
}
.eq .katex-display { margin: 0; }
.eq .katex { font-size: 1.16em; color: var(--text-bright); }
.eq .eq-note {
  margin-top: 16px; padding-top: 14px; border-top: 1px solid #1e2124;
  font-size: 13px; color: var(--text-secondary); line-height: 1.65; max-width: none;
}
.eq .eq-note .katex { font-size: 1em; color: var(--text); }
.katex { color: var(--text); }

/* ============================================================
   REFERENCES (per-concept linked primary sources) + global bibliography
   ============================================================ */
.ref-list {
  list-style: none; margin: 8px 0 0; padding: 0;
  counter-reset: ref;
}
.ref-list li {
  position: relative; padding: 12px 0 12px 40px;
  border-bottom: 1px solid var(--hairline);
  font-size: 14px; line-height: 1.6; color: var(--text-secondary);
}
.ref-list li:last-child { border-bottom: 0; }
.ref-list li::before {
  counter-increment: ref; content: "[" counter(ref) "]";
  position: absolute; left: 0; top: 12px;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.06em;
  color: var(--text-muted);
}
.ref-list a { color: var(--accent); text-decoration: none; border-bottom: 1px solid transparent; }
.ref-list a:hover { border-bottom-color: var(--accent); }
.ref-list .ref-meta { color: var(--text-muted); font-style: italic; }
.ref-list .ref-venue { font-style: italic; }
input[type="radio"], input[type="checkbox"], input[type="range"] { accent-color: var(--accent); }

/* ============================================================
   HUB — Part section dividers (track × level grouping)
   ============================================================ */
.part-label {
  margin: 64px 0 24px; padding-bottom: 10px;
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--text-secondary);
  border-bottom: 1px solid var(--hairline);
  display: flex; align-items: center; gap: 12px;
}
.part-label::before { content: ""; width: 10px; height: 10px; background: var(--accent); flex: 0 0 auto; }
.part-label:first-of-type { margin-top: 8px; }

/* ============================================================
   ONBOARDING (intent × depth router on the landing)
   ============================================================ */
.onboard { margin-top: 24px; }
.onboard .ob-q {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--text-muted); margin: 0 0 12px;
}
.onboard .ob-q2 { margin-top: 28px; }
.ob-chips, .ob-depths { display: flex; flex-wrap: wrap; gap: 8px; }
.ob-chip, .ob-depth {
  font-family: var(--font-mono); font-size: 13px; cursor: pointer;
  padding: 9px 14px; border-radius: 2px; color: var(--text-secondary);
  background: transparent; border: 1px solid var(--hairline); transition: border-color .15s, color .15s;
}
.ob-chip:hover, .ob-depth:hover { border-color: var(--text-muted); color: var(--text-bright); }
.ob-chip.on, .ob-depth.on { border-color: var(--accent); color: var(--text-bright); }
.ob-depth { font-size: 12px; padding: 8px 13px; }
.ob-result {
  margin-top: 28px; display: flex; gap: 28px; align-items: center; justify-content: space-between;
  padding: 22px 24px; border: 1px solid var(--hairline); border-left: 1px solid var(--accent);
  background: transparent; border-radius: 2px; flex-wrap: wrap;
}
.ob-result-l { flex: 1 1 320px; }
.ob-result .ob-kicker { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em; color: var(--accent); margin-bottom: 8px; }
.ob-result h3 { margin: 0 0 6px; font-size: 22px; color: var(--text-bright); }
.ob-result p { margin: 0 0 6px; color: var(--text-secondary); font-size: 15px; }
.ob-result .ob-tracks { font-family: var(--font-mono); font-size: 12px; color: var(--text-muted); margin-top: 8px; }
.ob-result-r { display: flex; flex-direction: column; gap: 10px; align-items: flex-start; flex: 0 0 auto; }
.ob-start {
  display: inline-block; padding: 11px 18px; background: transparent; color: var(--accent);
  border: 1px solid var(--accent); border-radius: 2px;
  font-size: 14px; text-decoration: none; transition: background .15s;
}
.ob-start:hover { background: var(--accent-05); }
.ob-map { color: var(--text-muted); font-size: 13px; text-decoration: none; }
.ob-map:hover { color: var(--text); }
.ob-fallback { margin-top: 20px; }
@media (max-width: 640px) { .ob-result { flex-direction: column; align-items: stretch; } .ob-result-r { align-items: stretch; } .ob-start { text-align: center; } }

/* ============================================================
   FIGURES / DIAGRAMS
   ============================================================ */
.figure {
  margin: 32px 0; border: 1px solid var(--hairline); border-radius: 4px;
  background:
    linear-gradient(rgba(47, 50, 52, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(47, 50, 52, 0.22) 1px, transparent 1px),
    #000;
  background-size: 24px 24px, 24px 24px, auto;
  overflow: hidden;
}
.figure .fig-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 12px 20px; border-bottom: 1px solid var(--hairline);
  background: rgba(0, 0, 0, 0.6);
}
.figure .fig-head .fig-id {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.2em;
  color: var(--accent); text-transform: uppercase;
}
.figure .fig-head .fig-title {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.14em;
  color: var(--text-muted); text-transform: uppercase; text-align: right;
}
.figure .fig-body { padding: 32px 24px; }
.figure .fig-body svg { display: block; width: 100%; height: auto; }
.figure .fig-cap {
  padding: 14px 20px; border-top: 1px solid var(--hairline);
  font-size: 12.5px; color: var(--text-secondary); line-height: 1.6;
  background: rgba(0, 0, 0, 0.6);
}
.figure .fig-cap b { color: var(--text); font-weight: 400; }

/* SVG diagram conventions */
.dg-box { fill: #1e2124; stroke: var(--border-strong); stroke-width: 1; }
.dg-box-accent { fill: var(--accent-deep); stroke: var(--accent); stroke-width: 1; }
.dg-box-ghost { fill: none; stroke: var(--hairline); stroke-width: 1; stroke-dasharray: 4 4; }
.dg-label { font-family: var(--font-mono); font-size: 11px; fill: var(--text); }
.dg-label-sm { font-family: var(--font-mono); font-size: 9.5px; fill: var(--text-secondary); }
.dg-label-mut { font-family: var(--font-mono); font-size: 9.5px; fill: var(--text-muted); }
.dg-label-acc { font-family: var(--font-mono); font-size: 10px; fill: var(--accent); }
.dg-line { stroke: var(--border-strong); stroke-width: 1.25; fill: none; }
.dg-line-acc { stroke: var(--accent); stroke-width: 1.25; fill: none; }
.dg-line-blue { stroke: var(--blue); stroke-width: 1.25; fill: none; }
.dg-dot { fill: var(--accent); }

/* ============================================================
   WIDGETS (interactive panels)
   ============================================================ */
.widget {
  margin: 32px 0; border: 1px solid var(--border-strong); border-radius: 4px;
  background: #000; overflow: hidden;
}
.widget .w-head {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 20px; border-bottom: 1px solid var(--hairline);
  background: var(--panel);
}
.widget .w-head .w-dot { width: 8px; height: 8px; background: var(--accent); animation: pulse 2.4s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.25; } }
.widget .w-head .w-title {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--text-bright);
}
.widget .w-head .w-sub {
  margin-left: auto; font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.1em; color: var(--text-muted); text-transform: uppercase;
}
.widget .w-body { padding: 24px; }
.widget .w-note {
  padding: 12px 20px; border-top: 1px solid var(--hairline);
  font-size: 12px; color: var(--text-muted); font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* controls */
.ctl-row { display: flex; gap: 24px; flex-wrap: wrap; align-items: flex-end; margin-bottom: 20px; }
.ctl { display: flex; flex-direction: column; gap: 8px; min-width: 160px; flex: 1; }
.ctl label {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--text-muted);
  display: flex; justify-content: space-between;
}
.ctl label output { color: var(--accent); letter-spacing: 0.04em; }
input[type="range"] {
  -webkit-appearance: none; appearance: none; width: 100%; height: 2px;
  background: var(--hairline); outline: none; border-radius: 0;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; width: 14px; height: 14px;
  background: var(--accent); cursor: ew-resize; border: 2px solid #000;
  box-shadow: 0 0 0 1px var(--accent); border-radius: 0;
}
input[type="range"]::-moz-range-thumb {
  width: 12px; height: 12px; background: var(--accent); cursor: ew-resize;
  border: 2px solid #000; box-shadow: 0 0 0 1px var(--accent); border-radius: 0;
}
.w-input {
  background: #000; border: 1px solid var(--hairline); border-radius: 4px;
  color: var(--text-bright); font-family: var(--font-mono); font-size: 13px;
  padding: 10px 14px; width: 100%;
  transition: border-color 0.25s ease-in-out;
}
.w-input:focus { outline: none; border-color: var(--accent); }
.w-btn {
  background: var(--accent); color: #000; border: 1px solid var(--accent);
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em;
  text-transform: uppercase; padding: 10px 20px; cursor: pointer; border-radius: 4px;
  transition: background 0.25s ease-in-out, color 0.25s ease-in-out;
}
.w-btn:hover { background: #000; color: var(--accent); }
.w-btn.ghost { background: transparent; color: var(--text-secondary); border-color: var(--hairline); }
.w-btn.ghost:hover { color: var(--text-bright); border-color: var(--border-strong); }
.w-btn.ghost.on { color: var(--accent); border-color: var(--accent-deep); background: var(--accent-05); }

/* widget readouts */
.readout-strip { display: flex; gap: 1px; background: var(--hairline); border: 1px solid var(--hairline); border-radius: 4px; overflow: hidden; margin-top: 20px; flex-wrap: wrap; }
.readout { flex: 1; min-width: 130px; background: #000; padding: 14px 16px; }
.readout .r-label {
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--text-muted); margin-bottom: 6px;
}
.readout .r-value { font-family: var(--font-mono); font-size: 18px; color: var(--text-bright); }
.readout .r-value small { font-size: 11px; color: var(--text-secondary); }
.readout.acc .r-value { color: var(--accent); }

/* token chips */
.tok-stream { display: flex; flex-wrap: wrap; gap: 6px; min-height: 44px; }
.tok-chip {
  font-family: var(--font-mono); font-size: 12.5px; padding: 6px 10px;
  border-radius: 4px; border: 1px solid; white-space: pre; cursor: default;
  transition: transform 0.15s var(--ease-expo);
}
.tok-chip:hover { transform: translateY(-2px); }
.tok-c0 { background: var(--accent-10); border-color: rgba(166,242,204,.35); color: var(--accent); }
.tok-c1 { background: var(--blue-10); border-color: rgba(78,138,247,.35); color: var(--blue); }
.tok-c2 { background: rgba(229,229,229,.07); border-color: rgba(229,229,229,.25); color: var(--text); }
.tok-c3 { background: rgba(43,89,69,.25); border-color: var(--accent-deep); color: #a6f2cc; }

canvas.w-canvas { display: block; width: 100%; border: 1px solid var(--hairline); border-radius: 4px; background: #000; }

/* ============================================================
   CARDS / CALLOUTS / TABLES
   ============================================================ */
.callout {
  margin: 28px 0; padding: 20px 24px; border: 1px solid var(--hairline);
  border-radius: 4px; background: var(--panel);
  display: grid; grid-template-columns: auto 1fr; gap: 16px; align-items: start;
}
.callout .co-icon {
  font-family: var(--font-mono); font-size: 11px; color: var(--accent);
  border: 1px solid var(--accent-deep); padding: 4px 8px; border-radius: 4px;
  letter-spacing: 0.1em; margin-top: 2px; white-space: nowrap;
}
.callout p { margin: 0; font-size: 13.5px; color: var(--text-secondary); max-width: none; }
.callout p strong, .callout p b { color: var(--text-bright); }
.callout.warn .co-icon { color: var(--danger); border-color: rgba(255, 65, 54, 0.4); }

.spec-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1px; background: var(--hairline); border: 1px solid var(--hairline); border-radius: 4px; overflow: hidden; margin: 28px 0; }
.spec-cell { background: #000; padding: 20px; }
.spec-cell .s-label { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 8px; }
.spec-cell .s-value { font-family: var(--font-display); font-weight: 700; font-size: 26px; color: var(--text-bright); letter-spacing: -0.01em; }
.spec-cell .s-value em { font-style: normal; color: var(--accent); }
.spec-cell .s-sub { font-size: 12px; color: var(--text-secondary); margin-top: 6px; }

table.data {
  width: 100%; border-collapse: collapse; margin: 28px 0; font-size: 13px;
}
table.data th {
  text-align: left; padding: 10px 14px; font-family: var(--font-mono);
  font-weight: 400; font-size: 10px; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 0.16em;
  border-bottom: 1px solid var(--border-strong);
}
table.data td {
  padding: 12px 14px; border-bottom: 1px solid #1e2124; color: var(--text);
  vertical-align: top;
}
table.data td.m { font-family: var(--font-mono); font-size: 12px; color: var(--text-secondary); }
table.data td.hl { color: var(--accent); font-family: var(--font-mono); font-size: 12px; }
table.data tr:hover td { background: var(--accent-05); }

/* ============================================================
   PREV / NEXT
   ============================================================ */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--hairline); border: 1px solid var(--hairline); margin: 96px 0 0; border-radius: 4px; overflow: hidden; }
.pager a {
  background: #000; padding: 32px 28px; text-decoration: none; display: block;
  transition: background 0.25s ease-in-out;
}
.pager a:hover { background: var(--panel); }
.pager a.next { text-align: right; }
.pager .p-dir { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 10px; }
.pager .p-title { font-family: var(--font-display); font-weight: 700; font-size: 22px; color: var(--text-bright); letter-spacing: -0.01em; }
.pager a:hover .p-title { color: var(--accent); }
.pager .p-num { color: var(--accent); font-family: var(--font-mono); font-size: 12px; }
.pager a.disabled { pointer-events: none; opacity: 1; }
.pager a.disabled .p-title { color: var(--text-muted); }
@media (max-width: 35em) { .pager { grid-template-columns: 1fr; } }

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  margin-top: 96px; border-top: 1px solid var(--hairline);
  padding: 48px 0 64px;
}
.footer .shell { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer .f-col { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-muted); line-height: 2.2; }
.footer a { color: var(--text-secondary); text-decoration: none; transition: color 0.25s ease-in-out; }
.footer a:hover { color: var(--accent); }

/* ============================================================
   INDEX (cover) PAGE
   ============================================================ */
.cover {
  position: relative; min-height: 100vh; display: flex; flex-direction: column;
  justify-content: center; overflow: hidden;
}
#cover-canvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: 1; }
.cover::after {
  content: ""; position: absolute; inset: 0; z-index: 2; pointer-events: none;
  background: radial-gradient(ellipse 70% 60% at 50% 45%, transparent 30%, #000 100%);
}
.cover .shell { position: relative; z-index: 3; width: 100%; }
.cover .cov-eyebrow {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.3em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 28px;
  display: flex; align-items: center; gap: 14px;
}
.cov-eyebrow::before { content: ""; width: 40px; height: 1px; background: var(--accent); }
.cover h1 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(56px, 10.5vw, 148px); line-height: 0.96;
  letter-spacing: -0.025em; color: var(--text-bright);
}
.cover h1 .line { display: block; overflow: hidden; }
.cover h1 .line > span { display: inline-block; }
.cover h1 em { font-style: normal; color: var(--accent); }
.cover .cov-sub {
  margin-top: 36px; font-size: 18px; line-height: 1.7; color: var(--text-secondary);
  max-width: 56ch;
}
.cover .cov-meta {
  margin-top: 48px; display: flex; gap: 40px; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--text-muted);
}
.cov-meta b { display: block; color: var(--text); font-weight: 400; margin-top: 6px; }
.scroll-cue {
  position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%); z-index: 3;
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.3em;
  text-transform: uppercase; color: var(--text-muted);
  display: flex; flex-direction: column; align-items: center; gap: 12px;
}
.scroll-cue .cue-line { width: 1px; height: 40px; background: var(--hairline); position: relative; overflow: hidden; }
.scroll-cue .cue-line::after {
  content: ""; position: absolute; top: -50%; left: 0; width: 100%; height: 50%;
  background: var(--accent); animation: cueDrop 2s var(--ease-expo) infinite;
}
@keyframes cueDrop { 0% { top: -50%; } 100% { top: 110%; } }

/* index — TOC */
.toc-section { padding: 128px 0; }
.toc-head { margin-bottom: 64px; }
.toc-head h2 {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(34px, 4.5vw, 56px); letter-spacing: -0.02em; color: var(--text-bright);
}
.idx-eyebrow {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.26em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 20px;
  display: flex; align-items: center; gap: 12px;
}
.idx-eyebrow::before { content: ""; width: 32px; height: 1px; background: var(--accent); }

.toc-list { border-top: 1px solid var(--hairline); }
.toc-item {
  display: grid; grid-template-columns: 72px minmax(0, 1.1fr) minmax(0, 1.4fr) 48px;
  gap: 24px; align-items: center;
  padding: 28px 8px; border-bottom: 1px solid var(--hairline);
  text-decoration: none; position: relative;
  transition: background 0.25s ease-in-out, padding-left 0.25s var(--ease-expo);
}
.toc-item:hover { background: var(--accent-05); padding-left: 20px; }
.toc-item .t-num { font-family: var(--font-mono); font-size: 13px; color: var(--text-muted); transition: color 0.25s ease-in-out; }
.toc-item:hover .t-num { color: var(--accent); animation: flickOn 0.3s steps(1) 1; }
.toc-item .t-title {
  font-family: var(--font-display); font-weight: 700; font-size: clamp(20px, 2.4vw, 28px);
  letter-spacing: -0.01em; color: var(--text-bright);
}
.toc-item .t-desc { font-size: 13px; line-height: 1.6; color: var(--text-secondary); }
.toc-item .t-desc .tags { display: block; margin-top: 6px; font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--text-muted); }
.toc-item .t-arrow { font-family: var(--font-mono); font-size: 16px; color: var(--text-muted); text-align: right; transition: color 0.25s ease-in-out, transform 0.25s var(--ease-expo); }
.toc-item:hover .t-arrow { color: var(--accent); transform: translateX(6px); }
@media (max-width: 47.4375em) {
  .toc-item { grid-template-columns: 48px 1fr 32px; }
  .toc-item .t-desc { display: none; }
}

/* index — stats strip */
.stats-strip { border: 1px solid var(--hairline); border-radius: 4px; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1px; background: var(--hairline); overflow: hidden; margin: 0 0 128px; }
.stat-cell { background: #000; padding: 32px 28px; }
.stat-cell .st-value { font-family: var(--font-display); font-weight: 700; font-size: clamp(30px, 3.6vw, 44px); color: var(--text-bright); letter-spacing: -0.02em; }
.stat-cell .st-value em { font-style: normal; color: var(--accent); }
.stat-cell .st-label { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--text-muted); margin-top: 10px; line-height: 1.8; }

/* notation table */
.notation { padding: 0 0 128px; }

/* how-to strip */
.howto { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; margin: 0 0 128px; }
.how-card { border: 1px solid var(--hairline); border-radius: 4px; padding: 28px 24px; background: #000; transition: border-color .25s ease-in-out, background .25s ease-in-out; }
.how-card:hover { border-color: var(--accent-deep); background: var(--accent-05); }
.how-card .h-num { font-family: var(--font-mono); font-size: 11px; color: var(--accent); letter-spacing: 0.2em; margin-bottom: 16px; }
.how-card h3 { font-family: var(--font-display); font-weight: 700; font-size: 18px; color: var(--text-bright); margin-bottom: 10px; }
.how-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.65; margin: 0; }

/* ============================================================
   MISC
   ============================================================ */
.kbd {
  font-family: var(--font-mono); font-size: 11px; color: var(--text-secondary);
  border: 1px solid var(--hairline); border-bottom-width: 2px; border-radius: 4px;
  padding: 2px 7px; background: var(--panel);
}

.attn-sentence { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 20px; }
.attn-tok {
  font-family: var(--font-mono); font-size: 13px; padding: 8px 12px;
  border: 1px solid var(--hairline); border-radius: 4px; cursor: pointer;
  color: var(--text); background: #000; position: relative;
  transition: border-color 0.15s ease-in-out, color 0.15s ease-in-out, background 0.15s ease-in-out;
}
.attn-tok.q { border-color: var(--accent); color: var(--accent); background: var(--accent-10); }
.attn-tok .w-pct {
  position: absolute; top: -18px; left: 50%; transform: translateX(-50%);
  font-size: 9px; color: var(--accent); letter-spacing: 0.04em; white-space: nowrap;
  opacity: 0; transition: opacity 0.15s;
}
.attn-tok.show-w .w-pct { opacity: 1; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ============================================================
   GLOSSARY TOOLTIPS
   ============================================================ */
.gloss {
  border-bottom: 1px dotted rgba(166, 242, 204, 0.8);
  cursor: help;
}
.gloss:hover { color: var(--text-bright); border-bottom-style: solid; }
.gloss-tip {
  position: fixed; z-index: 950; max-width: 340px;
  background: #1e2124; border: 1px solid var(--border-strong);
  border-left: 2px solid var(--accent); border-radius: 4px;
  padding: 12px 16px; pointer-events: none;
  opacity: 0; transform: translateY(4px);
  transition: opacity 0.15s ease-in-out, transform 0.15s ease-in-out;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}
.gloss-tip.show { opacity: 1; transform: translateY(0); }
.gloss-tip .gt-term {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 6px;
}
.gloss-tip .gt-body { font-size: 12.5px; line-height: 1.6; color: var(--text); }

/* ============================================================
   CAPSTONE — dossier + journey
   ============================================================ */
.dossier {
  border: 1px solid var(--border-strong); border-radius: 4px; overflow: hidden;
  background: #000; margin-top: 24px;
}
.dossier .do-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 20px; background: var(--panel); border-bottom: 1px solid var(--hairline);
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--text-bright);
}
.dossier .do-head .do-class { color: var(--accent); }
.dossier .do-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px; background: var(--hairline);
}
.dossier .do-cell { background: #000; padding: 16px 20px; }
.dossier .do-cell .d-label {
  font-family: var(--font-mono); font-size: 9px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--text-muted); margin-bottom: 6px;
}
.dossier .do-cell .d-value { font-family: var(--font-mono); font-size: 17px; color: var(--text-bright); }
.dossier .do-cell .d-value small { font-size: 11px; color: var(--text-secondary); }
.dossier .do-cell.hot .d-value { color: var(--accent); }
.dossier .do-cell.bad .d-value { color: var(--danger); }
.dossier .do-foot {
  padding: 12px 20px; border-top: 1px solid var(--hairline);
  font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 0.06em;
  color: var(--text-secondary); line-height: 1.8;
}

.stage-strip { display: flex; gap: 4px; margin: 20px 0; flex-wrap: wrap; }
.stage {
  flex: 1; min-width: 96px; border: 1px solid var(--hairline); border-radius: 4px;
  padding: 10px 8px; text-align: center;
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--text-muted);
  transition: border-color 0.2s ease-in-out, color 0.2s ease-in-out, background 0.2s ease-in-out;
}
.stage.on { border-color: var(--accent); color: var(--accent); background: var(--accent-05); }
.stage .st-sub { display: block; font-size: 8.5px; color: var(--text-muted); margin-top: 4px; letter-spacing: 0.06em; text-transform: none; }

.seg-row { display: flex; gap: 8px; flex-wrap: wrap; }
.seg-row .w-btn { flex: 0 0 auto; }

/* ============================================================
   PYTHON CELLS (Pyodide)
   ============================================================ */
.pycell { margin: 28px 0; border: 1px solid var(--border-strong); border-radius: 4px; background: #000; overflow: hidden; }
.pycell .py-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 16px; background: var(--panel); border-bottom: 1px solid var(--hairline);
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--accent);
}
.pycell .py-status { color: var(--text-muted); letter-spacing: 0.1em; }
.pycell .py-src {
  margin: 0; border: 0; border-radius: 0; background: #000;
  padding: 18px 20px; font-size: 13px; line-height: 1.7; color: var(--text);
  outline: none; white-space: pre-wrap; min-height: 48px;
}
.pycell .py-src:focus { background: rgba(166, 242, 204, 0.03); }
.pycell .py-bar {
  display: flex; align-items: center; gap: 16px; padding: 10px 16px;
  border-top: 1px solid var(--hairline);
}
.pycell .py-note { font-family: var(--font-mono); font-size: 10px; color: var(--text-muted); letter-spacing: 0.08em; text-transform: uppercase; }
.pycell .py-out {
  margin: 0; border: 0; border-top: 1px solid var(--hairline); border-radius: 0;
  background: rgba(166, 242, 204, 0.04); color: var(--text-secondary);
  padding: 14px 20px; font-size: 12.5px; max-height: 260px; overflow: auto;
}
.pycell .py-plot { display: block; width: 100%; border-top: 1px solid var(--hairline); background: #000; }

/* ============================================================
   SEARCH PALETTE (⌘K)
   ============================================================ */
.pal-overlay {
  position: fixed; inset: 0; z-index: 925; background: rgba(0, 0, 0, 0.78);
  display: none; align-items: flex-start; justify-content: center; padding: 12vh 24px 0;
}
.pal-overlay.show { display: flex; }
.pal-box {
  width: 100%; max-width: 640px; background: var(--panel);
  border: 1px solid var(--border-strong); border-radius: 10px; overflow: hidden;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}
.pal-head { display: flex; align-items: center; gap: 12px; padding: 16px 20px; border-bottom: 1px solid var(--hairline); }
.pal-input {
  flex: 1; background: transparent; border: 0; outline: none;
  color: var(--text-bright); font-family: var(--font-mono); font-size: 15px;
}
.pal-input::placeholder { color: var(--text-muted); }
.pal-esc { font-family: var(--font-mono); font-size: 9px; color: var(--text-muted); border: 1px solid var(--hairline); padding: 3px 6px; border-radius: 4px; letter-spacing: 0.1em; }
.pal-list { max-height: 50vh; overflow-y: auto; }
.pal-item {
  display: flex; align-items: center; gap: 14px; padding: 12px 20px;
  text-decoration: none; border-bottom: 1px solid rgba(47, 50, 52, 0.5);
}
.pal-item:hover, .pal-item.sel { background: var(--accent-05); }
.pal-item .pi-vol { font-family: var(--font-mono); font-size: 9px; letter-spacing: 0.14em; color: var(--accent); min-width: 44px; }
.pal-item .pi-main { flex: 1; min-width: 0; }
.pal-item .pi-title { display: block; color: var(--text-bright); font-size: 14px; font-family: var(--font-display); font-weight: 700; }
.pal-item .pi-sec { display: block; color: var(--text-secondary); font-size: 11.5px; font-family: var(--font-mono); margin-top: 2px; }
.pal-item .pi-arrow { color: var(--text-muted); font-family: var(--font-mono); }
.pal-item.sel .pi-arrow { color: var(--accent); }
.pal-empty { padding: 24px 20px; color: var(--text-muted); font-family: var(--font-mono); font-size: 12px; }
.pal-foot { padding: 10px 20px; border-top: 1px solid var(--hairline); font-family: var(--font-mono); font-size: 9px; letter-spacing: 0.16em; color: var(--text-muted); }

/* ============================================================
   HUB — volume groups, level badges, progress
   ============================================================ */
.vol-block { margin-bottom: 96px; }
.vol-head { display: flex; align-items: baseline; gap: 20px; margin-bottom: 24px; flex-wrap: wrap; }
.vol-head .v-tag {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.22em;
  color: #000; background: var(--accent); padding: 6px 10px; border-radius: 4px;
}
.vol-head h3 { font-family: var(--font-display); font-weight: 700; font-size: clamp(22px, 3vw, 32px); color: var(--text-bright); letter-spacing: -0.01em; }
.vol-head .v-sub { font-family: var(--font-mono); font-size: 11px; color: var(--text-muted); letter-spacing: 0.1em; text-transform: uppercase; }

.lvl { font-family: var(--font-mono); font-size: 8.5px; letter-spacing: 0.16em; padding: 3px 7px; border-radius: 4px; border: 1px solid var(--hairline); color: var(--text-muted); white-space: nowrap; }
.lvl.intro { color: var(--accent); border-color: var(--accent-deep); }
.lvl.adv { color: var(--blue); border-color: rgba(78, 138, 247, 0.4); }

.toc-item .t-done { font-family: var(--font-mono); font-size: 12px; color: var(--accent-deep); }
.toc-item.is-done .t-done { color: var(--accent); }
.toc-item.is-done .t-num { color: var(--accent); }

.gym-banner {
  display: grid; grid-template-columns: 1fr auto; gap: 24px; align-items: center;
  border: 1px solid var(--accent-deep); border-radius: 4px; padding: 32px;
  background: linear-gradient(135deg, rgba(43, 89, 69, 0.25), rgba(0, 0, 0, 0)) , #000;
  margin-bottom: 96px;
}
.gym-banner h3 { font-family: var(--font-display); font-weight: 700; font-size: clamp(24px, 3vw, 34px); color: var(--text-bright); margin-bottom: 8px; }
.gym-banner p { color: var(--text-secondary); font-size: 14px; max-width: 60ch; margin: 0; }
.gym-banner .gb-cta {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.16em;
  background: var(--accent); color: #000; padding: 14px 24px; border-radius: 4px;
  text-decoration: none; white-space: nowrap; transition: opacity 0.25s ease-in-out;
}
.gym-banner .gb-cta:hover { opacity: 0.85; }
@media (max-width: 47.4375em) { .gym-banner { grid-template-columns: 1fr; } }

/* ============================================================
   GYM
   ============================================================ */
.gym-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; margin: 32px 0; }
.deck-card {
  border: 1px solid var(--hairline); border-radius: 4px; background: #000; padding: 24px;
  cursor: pointer; transition: border-color 0.25s ease-in-out, background 0.25s ease-in-out;
}
.deck-card:hover { border-color: var(--accent-deep); background: var(--accent-05); }
.deck-card .dk-vol { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.2em; color: var(--accent); margin-bottom: 10px; }
.deck-card h3 { font-family: var(--font-display); font-weight: 700; font-size: 20px; color: var(--text-bright); margin-bottom: 8px; }
.deck-card p { font-size: 12.5px; color: var(--text-secondary); margin-bottom: 14px; }
.deck-card .dk-meta { font-family: var(--font-mono); font-size: 10px; color: var(--text-muted); letter-spacing: 0.1em; }
.deck-card .dk-best { color: var(--accent); }

.drill { border: 1px solid var(--border-strong); border-radius: 4px; background: #000; margin: 24px 0; overflow: hidden; }
.drill .dr-head { display: flex; justify-content: space-between; padding: 12px 20px; background: var(--panel); border-bottom: 1px solid var(--hairline); font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.16em; color: var(--text-secondary); text-transform: uppercase; }
.drill .dr-q { padding: 24px; font-size: 16px; color: var(--text-bright); line-height: 1.6; }
.drill .dr-q .katex { font-size: 1em; }
.drill .dr-opts { padding: 0 24px 20px; display: grid; gap: 8px; }
.drill .dr-opt {
  text-align: left; background: #000; border: 1px solid var(--hairline); border-radius: 4px;
  padding: 12px 16px; color: var(--text); font-family: var(--font-body); font-size: 14px;
  cursor: pointer; transition: border-color 0.15s ease-in-out, background 0.15s ease-in-out;
}
.drill .dr-opt:hover { border-color: var(--border-strong); }
.drill .dr-opt.right { border-color: var(--accent); background: var(--accent-10); color: var(--accent); }
.drill .dr-opt.wrong { border-color: var(--danger); background: rgba(255, 65, 54, 0.08); color: var(--danger); }
.drill .dr-exp { margin: 0 24px 20px; padding: 14px 16px; border-left: 2px solid var(--accent); background: var(--accent-05); font-size: 13px; color: var(--text-secondary); display: none; }
.drill .dr-exp.show { display: block; }
.drill .dr-exp b { color: var(--text-bright); }

/* ============================================================
   THE LAB — right-docked Python panel (pyrunner v2)
   Inline .pycell blocks collapse to chips; code runs in a
   side panel so prose and code read side-by-side on desktop.
   On narrow screens chips expand in place instead.
   ============================================================ */
.py-chip {
  display: flex; align-items: center; gap: 14px;
  margin: 24px 0; padding: 14px 18px;
  border: 1px solid var(--accent-deep); border-radius: 4px;
  background: var(--accent-05); cursor: pointer;
  transition: border-color 0.2s ease-in-out, background 0.2s ease-in-out;
}
.py-chip:hover { border-color: var(--accent); background: var(--accent-10); }
.py-chip .pc-icon {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.14em;
  color: #000; background: var(--accent); padding: 4px 8px; border-radius: 4px; flex: none;
}
.py-chip .pc-title { flex: 1; min-width: 0; }
.py-chip .pc-title b { display: block; color: var(--text-bright); font-family: var(--font-display); font-weight: 700; font-size: 14px; }
.py-chip .pc-title span { display: block; color: var(--text-secondary); font-family: var(--font-mono); font-size: 10.5px; margin-top: 2px; letter-spacing: 0.04em; }
.py-chip .pc-cta { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.16em; color: var(--accent); white-space: nowrap; }

.lab-panel {
  position: fixed; top: 56px; right: 0; bottom: 0; z-index: 910;
  width: min(580px, 94vw);
  background: #000; border-left: 1px solid var(--border-strong);
  transform: translateX(102%); transition: transform 0.3s var(--ease-expo);
  display: flex; flex-direction: column;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}
.lab-panel.open { transform: translateX(0); }
.lab-head {
  display: flex; align-items: center; gap: 12px; padding: 14px 20px;
  border-bottom: 1px solid var(--hairline); background: var(--panel); flex: none;
}
.lab-head .lh-dot { width: 8px; height: 8px; background: var(--accent); animation: pulse 2.4s ease-in-out infinite; }
.lab-head .lh-title { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em; color: var(--text-bright); text-transform: uppercase; flex: 1; }
.lab-head .lh-close {
  background: none; border: 1px solid var(--hairline); border-radius: 4px; color: var(--text-secondary);
  font-family: var(--font-mono); font-size: 10px; padding: 6px 10px; cursor: pointer; letter-spacing: 0.1em;
}
.lab-head .lh-close:hover { color: var(--text-bright); border-color: var(--border-strong); }
.lab-tabs { display: flex; gap: 2px; padding: 10px 16px 0; border-bottom: 1px solid var(--hairline); overflow-x: auto; flex: none; }
.lab-tab {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--text-muted); background: none; border: 1px solid transparent; border-bottom: 0;
  border-radius: 4px 4px 0 0; padding: 8px 12px; cursor: pointer; white-space: nowrap;
}
.lab-tab:hover { color: var(--text-secondary); }
.lab-tab.on { color: var(--accent); border-color: var(--hairline); background: var(--accent-05); }
.lab-body { flex: 1; overflow-y: auto; }
.lab-body .pycell { margin: 0; border: 0; border-radius: 0; }
.lab-body .pycell .py-src { min-height: 120px; font-size: 12.5px; }
.lab-hint { padding: 10px 20px; border-top: 1px solid var(--hairline); font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.1em; color: var(--text-muted); flex: none; text-transform: uppercase; }

@media (max-width: 59.9375em) {
  .lab-panel { display: none; }
  .py-chip.expanded + .pycell { display: block !important; }
}

/* ============================================================
   EQ WORKED EXAMPLES & MINI-EVALUATORS (.eq-x)
   ============================================================ */
.eq .eq-x { margin-top: 14px; border-top: 1px solid #1e2124; padding-top: 12px; }
.eq .eq-x-toggle {
  background: none; border: 1px solid var(--hairline); border-radius: 4px;
  color: var(--accent); font-family: var(--font-mono); font-size: 9.5px;
  letter-spacing: 0.16em; text-transform: uppercase; padding: 7px 12px; cursor: pointer;
  transition: border-color 0.2s ease-in-out, background 0.2s ease-in-out;
}
.eq .eq-x-toggle:hover { border-color: var(--accent-deep); background: var(--accent-05); }
.eq .eq-x-body { margin-top: 14px; font-size: 13px; line-height: 1.7; color: var(--text-secondary); }
.eq .eq-x-body .x-step { display: flex; gap: 12px; margin-bottom: 8px; }
.eq .eq-x-body .x-step .x-n { font-family: var(--font-mono); font-size: 10px; color: var(--accent); flex: none; padding-top: 3px; }
.eq .eq-x-body b, .eq .eq-x-body .x-hl { color: var(--text-bright); }
.eq .eq-x-body .x-result {
  font-family: var(--font-mono); font-size: 13px; color: var(--accent);
  border: 1px solid var(--accent-deep); border-radius: 4px; background: var(--accent-05);
  padding: 8px 12px; display: inline-block; margin-top: 4px;
}
.eq .eq-try { display: flex; gap: 14px; flex-wrap: wrap; align-items: flex-end; margin-top: 12px; }
.eq .eq-try .ctl { min-width: 110px; flex: 0 1 150px; }
.eq .eq-try .try-out {
  font-family: var(--font-mono); font-size: 14px; color: var(--accent);
  border-left: 2px solid var(--accent); padding: 6px 12px; background: var(--accent-05);
  min-width: 140px;
}

/* when the Lab is open (desktop), reflow content beside it */
@media (min-width: 60em) {
  body.lab-open .shell {
    max-width: none;
    margin: 0;
    padding-right: calc(min(580px, 94vw) + 32px);
  }
  body.lab-open { scrollbar-gutter: stable; }
}

/* ============================================================
   GYM v2 — engine chrome for /gym (appended; nothing above
   this banner was modified). Palette-locked, 4px grid.
   Views: stats strip → deck cards → deck intro → drill flow
   → end screen. All new class names are gx-/gxv2- prefixed
   and scoped to the gym page sections.
   ============================================================ */

/* ---- home: stats strip ---- */
.gxv2-stats {
  display: flex; gap: 1px; flex-wrap: wrap;
  background: var(--hairline); border: 1px solid var(--hairline);
  border-radius: 4px; overflow: hidden; margin: 0 0 32px;
}
.gxv2-stat { flex: 1; min-width: 148px; background: #000; padding: 16px 20px; }
.gxv2-stat .s-label {
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.18em;
  color: var(--text-muted); text-transform: uppercase; margin-bottom: 6px;
}
.gxv2-stat .s-value { font-family: var(--font-mono); font-size: 20px; color: var(--text-bright); }
.gxv2-stat .s-value small { font-size: 12px; color: var(--text-secondary); }
.gxv2-stat.acc .s-value { color: var(--accent); }

/* ---- home: deck card v2 additions ---- */
.deck-card.gxv2-deck { position: relative; display: flex; flex-direction: column; }
.section .deck-card.gxv2-deck h3 { margin-top: 0; } /* defuse generic .section h3 top margin inside cards */
.gxv2-badge {
  position: absolute; top: 20px; right: 20px;
  font-family: var(--font-mono); font-size: 9px; letter-spacing: 0.16em;
  color: var(--accent); border: 1px solid var(--accent-deep);
  background: var(--accent-05); border-radius: 3px; padding: 3px 8px;
}
.gxv2-deck .dk-meta { margin-top: auto; }
.gxv2-cta {
  display: flex; justify-content: space-between; align-items: center;
  margin-top: 16px; padding-top: 12px; border-top: 1px solid var(--hairline);
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.16em;
  color: var(--text-muted);
}
.gxv2-cta .go { color: var(--text-secondary); transition: color 0.2s ease-in-out, transform 0.25s var(--ease-expo); }
.deck-card.gxv2-deck:hover .gxv2-cta .go { color: var(--accent); transform: translateX(4px); }

/* ---- deck intro ---- */
.gxv2-intro { border: 1px solid var(--border-strong); border-radius: 4px; background: #000; overflow: hidden; }
.gxv2-intro .gi-head {
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
  padding: 12px 20px; background: var(--panel); border-bottom: 1px solid var(--hairline);
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.16em;
  color: var(--text-secondary); text-transform: uppercase;
}
.gxv2-intro .gi-body { padding: 32px 28px; }
.gxv2-intro .gi-vol { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.2em; color: var(--accent); margin-bottom: 12px; }
.gxv2-intro h2 { font-family: var(--font-display); font-weight: 700; font-size: clamp(26px, 4vw, 40px); color: var(--text-bright); margin-bottom: 12px; }
.gxv2-intro .gi-desc { color: var(--text-secondary); font-size: 14px; line-height: 1.7; max-width: 62ch; margin-bottom: 24px; }
.gxv2-mix { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 8px; }
.gxv2-mix span {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.14em;
  color: var(--text-secondary); border: 1px solid var(--hairline);
  border-radius: 3px; padding: 5px 10px; text-transform: uppercase;
}
.gxv2-mix span b { color: var(--accent); font-weight: 400; }
.gxv2-introbar { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-top: 28px; }
.gxv2-bigbtn {
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.18em; text-transform: uppercase;
  background: var(--accent); color: #000; border: 1px solid var(--accent);
  border-radius: 4px; padding: 16px 36px; cursor: pointer;
  transition: background 0.2s ease-in-out, color 0.2s ease-in-out;
}
.gxv2-bigbtn:hover { background: #000; color: var(--accent); }
.gxv2-kbd { font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.14em; color: var(--text-muted); text-transform: uppercase; margin-top: 16px; }

/* ---- drill flow chrome ---- */
.gx-runbar { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.gx-decktitle { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em; color: var(--text-muted); text-transform: uppercase; }
.gxv2-prog { height: 3px; background: var(--hairline); border-radius: 2px; overflow: hidden; margin-top: 14px; }
.gxv2-prog .fill { height: 100%; width: 0; background: var(--accent); transition: width 0.45s var(--ease-expo); }
#gym-run .drill .dr-head { flex-wrap: wrap; gap: 4px 12px; }
.gxv2-streak { font-family: var(--font-mono); color: var(--text-muted); display: inline-flex; gap: 7px; align-items: center; }
.gxv2-streak .tk { width: 6px; height: 6px; background: var(--border-strong); display: inline-block; }
.gxv2-streak.hot { color: var(--accent); }
.gxv2-streak.hot .tk { background: var(--accent); animation: pulse 1.6s ease-in-out infinite; }
.gxv2-streak.pop { animation: gxv2pop 0.35s var(--ease-expo); }
@keyframes gxv2pop { 0% { transform: scale(1.4); } 100% { transform: scale(1); } }

.drill .dr-opt .gx-key {
  font-family: var(--font-mono); font-size: 10px; color: var(--text-muted);
  border: 1px solid var(--hairline); border-radius: 3px; padding: 1px 6px; margin-right: 8px;
}
.drill .dr-opt.right .gx-key { color: var(--accent); border-color: var(--accent-deep); }
.drill .dr-opt.wrong .gx-key { color: var(--danger); border-color: rgba(255, 65, 54, 0.4); }
.drill .dr-opt.lock { pointer-events: none; }
.drill .dr-opt.lock:not(.right):not(.wrong) { opacity: 0.45; }

.gx-foot {
  display: flex; justify-content: space-between; align-items: center; gap: 12px 16px;
  flex-wrap: wrap; padding: 14px 24px; border-top: 1px solid var(--hairline); background: var(--panel);
}
.gx-foot .gx-actions { display: flex; gap: 10px; align-items: center; margin-left: auto; }
.gx-status { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; color: var(--text-muted); }
.gx-status.ok { color: var(--accent); }
.gx-status.bad { color: var(--danger); }

.gx-numrow { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.gx-input {
  font-family: var(--font-mono); font-size: 16px; color: var(--text-bright);
  background: #000; border: 1px solid var(--border-strong); border-radius: 4px;
  padding: 10px 14px; width: 200px; max-width: 100%; outline: none;
}
.gx-input:focus { border-color: var(--accent-deep); background: var(--accent-05); }
.gx-input.right { border-color: var(--accent); color: var(--accent); background: var(--accent-10); }
.gx-input.wrong { border-color: var(--danger); color: var(--danger); background: rgba(255, 65, 54, 0.08); }
.gx-unit { font-family: var(--font-mono); font-size: 12px; color: var(--text-secondary); letter-spacing: 0.08em; }
.gx-hint { font-family: var(--font-mono); font-size: 10px; color: var(--text-muted); letter-spacing: 0.12em; margin-top: 10px; }

.gx-code {
  font-family: var(--font-mono); font-size: 12.5px; line-height: 1.7; color: var(--text);
  background: #000; border: 1px solid var(--hairline); border-radius: 4px;
  padding: 16px 18px; white-space: pre; overflow-x: auto; outline: none; tab-size: 4;
}
.gx-code:focus { border-color: var(--accent-deep); background: rgba(166, 242, 204, 0.03); }
.gx-bar { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; margin-top: 12px; }
.gx-pystatus { font-family: var(--font-mono); font-size: 10px; color: var(--text-muted); letter-spacing: 0.1em; text-transform: uppercase; }
.gx-out {
  font-family: var(--font-mono); font-size: 12px; line-height: 1.7; color: var(--text-secondary);
  background: #000; border: 1px solid var(--hairline); border-radius: 4px;
  padding: 14px 18px; margin-top: 12px; white-space: pre-wrap; max-height: 280px; overflow-y: auto;
}
.gx-out.pass { border-color: var(--accent-deep); color: var(--accent); }
.gx-out.fail { border-color: rgba(255, 65, 54, 0.4); color: var(--danger); }

/* ---- end screen ---- */
.gxv2-resgrid { display: flex; gap: 32px; align-items: center; flex-wrap: wrap; }
.gxv2-ringwrap { flex: 0 0 auto; margin: 0 auto; }
.gxv2-resgrid .readout-strip { flex: 1; min-width: 240px; margin-top: 0; }
.gxv2-newbest {
  display: inline-block; font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.18em; color: #000; background: var(--accent);
  border-radius: 3px; padding: 5px 10px; animation: gxv2pop 0.5s var(--ease-expo);
}
.gx-card { display: block; width: 100%; max-width: 640px; height: auto; border: 1px solid var(--hairline); border-radius: 4px; margin: 24px 0 0; }
.gx-resbar { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 20px; }

/* ---- narrow screens (≥380px must work) ---- */
@media (max-width: 30em) {
  .gxv2-intro .gi-body { padding: 24px 16px; }
  .gxv2-bigbtn { width: 100%; padding: 16px 20px; }
  .gxv2-introbar .w-btn { flex: 1; }
  #gym-run .drill .dr-q { padding: 20px 16px; }
  #gym-run .drill .dr-opts { padding: 0 16px 16px; }
  #gym-run .drill .dr-exp { margin: 0 16px 16px; }
  #gym-run .gx-foot { padding: 12px 16px; }
  #gym-run .gx-foot .gx-actions { margin-left: 0; width: 100%; }
  #gym-run .gx-foot .gx-actions .w-btn { flex: 1; }
  .gx-resbar .w-btn { flex: 1 1 45%; }
}

/* ============================================================
   MOBILE TOPBAR — compact mode (was overflowing by ~300px)
   ============================================================ */
@media (max-width: 47.4375em) {
  .topbar { gap: 6px; padding: 0 12px; }
  .topbar .crumb { display: none; }
  .topbar .pal-trigger { display: none; }
  .topbar .wordmark { font-size: 10px; letter-spacing: 0.1em; gap: 7px; }
  .topbar .bar-link { font-size: 9px; padding: 8px 6px; letter-spacing: 0.06em; }
  .topbar .bar-link.primary {
    max-width: 38vw; overflow: hidden; text-overflow: ellipsis;
  }
}

/* ============================================================
   MOBILE CONTENT SAFETY — tables scroll, long tokens wrap
   ============================================================ */
.section p, .section li, .eq-note, .w-note { overflow-wrap: break-word; }
@media (max-width: 47.4375em) {
  table.data { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
  code { word-break: break-word; }
  .w-btn { white-space: normal; line-height: 1.5; }
  .readout .r-value { font-size: 15px; }
  pre { font-size: 11.5px; padding: 14px 16px; }
}

.vol-head .v-prog {
  margin-left: auto; font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.14em; color: var(--accent); border: 1px solid var(--accent-deep);
  border-radius: 4px; padding: 4px 10px; white-space: nowrap;
}
.vol-head .v-prog:empty { display: none; }
.vol-head .v-prog.full { background: var(--accent); color: #000; border-color: var(--accent); }

/* collapsible table of contents — each track's chapter list folds away */
.vol-head { cursor: pointer; }
.vol-head::after {
  content: ""; flex: 0 0 auto; margin-left: auto; align-self: center;
  width: 7px; height: 7px; border-right: 1.5px solid var(--text-muted); border-bottom: 1.5px solid var(--text-muted);
  transform: rotate(45deg); transition: transform .15s; opacity: .55;
}
.vol-block.open > .vol-head::after { transform: rotate(-135deg); }
.vol-head:hover::after { opacity: 1; border-color: var(--accent); }
.vol-block:not(.open) .toc-list { display: none; }

/* pre-enhancement pycells: collapsed preview until pyrunner docks them
   (prevents the giant-terminal flash; no-JS readers still see the code) */
.pycell[data-py]:not(.wired) { max-height: 120px; overflow: hidden; position: relative; }
.pycell[data-py]:not(.wired)::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 64px;
  background: linear-gradient(rgba(0,0,0,0), #000);
}

/* instrument permalinks */
.w-head .w-link {
  background: none; border: 0; color: var(--text-muted); cursor: pointer;
  font-family: var(--font-mono); font-size: 12px; padding: 2px 6px;
  transition: color 0.2s ease-in-out;
}
.w-head .w-link:hover { color: var(--accent); }
.widget:target { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent-deep); }
.widget { scroll-margin-top: 88px; }

/* ============================================================
   FULL-WIDTH PROSE — text matches tables/figures (user request)
   ============================================================ */
.section p, .section ul, .section ol, .section p.note { max-width: none; }
.chapter-hero .lede { max-width: none; }

/* ============================================================
   GYM v3 — write-the-prompt katas (appended; nothing above this
   banner was modified). Palette-locked, 4px grid. New surfaces:
   deck-card tag, intro grading note, the prompt-kata brief
   (scenario + source + task), the writing textarea, the five-
   anchor static verdict panel, the BYOK deep-grade box with its
   judge scorecard, and the editorial (model solution + copy).
   All class names are gxv3- prefixed.
   ============================================================ */

/* ---- deck card: "WRITE & GET GRADED" tag ---- */
.gxv3-tag {
  display: inline-block; align-self: flex-start;
  font-family: var(--font-mono); font-size: 9px; letter-spacing: 0.16em;
  color: #000; background: var(--accent); border-radius: 3px;
  padding: 3px 8px; margin-bottom: 10px; text-transform: uppercase;
}

/* ---- intro: two-tier grading note ---- */
.gxv3-intronote {
  margin-top: 20px; padding: 14px 16px;
  border: 1px solid var(--accent-deep); border-radius: 4px;
  background: var(--accent-05);
  font-size: 12.5px; line-height: 1.7; color: var(--text-secondary);
}
.gxv3-intronote b { color: var(--text-bright); }

/* ---- the brief: scenario + source + task ---- */
.gxv3-title {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em;
  color: var(--accent); text-transform: uppercase; margin-bottom: 12px;
}
.gxv3-scenario { font-size: 14.5px; line-height: 1.7; color: var(--text); max-width: 72ch; margin-bottom: 18px; }
.gxv3-srclabel {
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.18em;
  color: var(--text-muted); text-transform: uppercase; margin-bottom: 6px;
}
.gxv3-source {
  font-family: var(--font-mono); font-size: 12px; line-height: 1.7;
  color: var(--text-secondary); background: #000;
  border: 1px solid var(--hairline); border-radius: 4px;
  padding: 14px 16px; margin: 0 0 16px; white-space: pre-wrap; overflow-x: auto;
}
.gxv3-taskline {
  display: flex; gap: 12px; align-items: baseline;
  border-left: 2px solid var(--accent); background: var(--accent-05);
  padding: 10px 14px; font-size: 13.5px; line-height: 1.65; color: var(--text);
}
.gxv3-taskline .tl-k {
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.16em;
  color: var(--accent); white-space: nowrap; flex: none;
}

/* ---- the writing surface ---- */
.gxv3-talabel {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em;
  color: var(--text-secondary); text-transform: uppercase; margin-bottom: 8px;
}
.gxv3-ta {
  width: 100%; min-height: 200px; resize: vertical; outline: none;
  font-family: var(--font-mono); font-size: 13px; line-height: 1.7;
  color: var(--text-bright); background: #000;
  border: 1px solid var(--border-strong); border-radius: 4px;
  padding: 14px 16px; tab-size: 4;
}
.gxv3-ta:focus { border-color: var(--accent-deep); background: rgba(166, 242, 204, 0.03); }
.gxv3-ta[readonly] { opacity: 0.7; }
.gxv3-ta::placeholder { color: var(--text-muted); }

/* ---- tier-1 verdict panel: five anchors ---- */
.gxv3-verdict { margin-top: 14px; border: 1px solid var(--hairline); border-radius: 4px; overflow: hidden; }
.gxv3-vhead {
  display: flex; justify-content: space-between; gap: 12px;
  padding: 9px 14px; background: var(--panel);
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.16em;
  color: var(--text-secondary); text-transform: uppercase;
}
.gxv3-vrow {
  display: grid; grid-template-columns: 46px 104px 1fr; gap: 12px;
  align-items: baseline; padding: 9px 14px; border-top: 1px solid var(--hairline);
}
.gxv3-vrow .v-stat { font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.12em; }
.gxv3-vrow.pass .v-stat { color: var(--accent); }
.gxv3-vrow.miss .v-stat { color: var(--danger); }
.gxv3-vrow .v-k { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; color: var(--text-bright); }
.gxv3-vrow .v-note { font-size: 12.5px; line-height: 1.6; color: var(--text-secondary); }
.gxv3-vrow .v-note .vn-fix { color: var(--danger); font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.1em; }
.gxv3-vrow .v-note .vn-na { color: var(--text-muted); font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.06em; }

/* ---- after-grade actions + deep grade (BYOK) ---- */
.gxv3-after { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }
.gxv3-deepbox {
  margin-top: 12px; border: 1px solid var(--hairline); border-radius: 4px;
  padding: 14px 16px; background: #000;
}
.gxv3-deeprow { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 10px; }
.gxv3-key { flex: 1 1 220px; width: auto; font-size: 12px; }
.gxv3-model {
  font-family: var(--font-mono); font-size: 11px; color: var(--text);
  background: #000; border: 1px solid var(--border-strong); border-radius: 4px;
  padding: 10px 12px; outline: none; cursor: pointer;
}
.gxv3-model:focus { border-color: var(--accent-deep); }
.gxv3-deepout { margin-top: 4px; }
.gxv3-err {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.08em;
  color: var(--danger); border-left: 2px solid var(--danger);
  background: rgba(255, 65, 54, 0.08); padding: 8px 12px; margin-top: 8px;
}
.gxv3-rawjudge {
  font-family: var(--font-mono); font-size: 11px; line-height: 1.6;
  color: var(--text-muted); background: #000; border: 1px solid var(--hairline);
  border-radius: 4px; padding: 10px 12px; margin-top: 8px;
  white-space: pre-wrap; max-height: 180px; overflow-y: auto;
}

/* ---- judge scorecard ---- */
.gxv3-scorecard { margin-top: 10px; border: 1px solid var(--hairline); border-radius: 4px; overflow: hidden; }
.gxv3-scorecard .sc-head {
  display: flex; justify-content: space-between; gap: 12px;
  padding: 9px 12px; background: var(--panel);
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.14em;
  color: var(--text-secondary); text-transform: uppercase;
}
.gxv3-scorecard .sc-head .ok { color: var(--accent); font-weight: 400; }
.gxv3-scorecard .sc-head .bad { color: var(--danger); font-weight: 400; }
.gxv3-scorecard .sc-row {
  display: grid; grid-template-columns: 104px 1fr 36px; gap: 12px;
  align-items: center; padding: 8px 12px; border-top: 1px solid var(--hairline);
}
.gxv3-scorecard .sc-k { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; color: var(--text-secondary); }
.gxv3-scorecard .sc-track { display: block; height: 6px; background: var(--hairline); border-radius: 3px; overflow: hidden; }
.gxv3-scorecard .sc-fill { display: block; height: 100%; background: var(--accent-deep); }
.gxv3-scorecard .sc-fill.full { background: var(--accent); }
.gxv3-scorecard .sc-v { font-family: var(--font-mono); font-size: 10.5px; color: var(--text-bright); text-align: right; }
.gxv3-scorecard .sc-fb {
  margin: 0; padding: 10px 14px 12px 30px; border-top: 1px solid var(--hairline);
  font-size: 12.5px; line-height: 1.7; color: var(--text-secondary); list-style: square;
}

/* ---- editorial: the model solution ---- */
.gxv3-solbox { margin-top: 14px; }
.gxv3-sol {
  font-family: var(--font-mono); font-size: 12px; line-height: 1.7;
  color: var(--text); background: var(--accent-05);
  border: 1px solid var(--accent-deep); border-radius: 4px;
  padding: 14px 16px; margin: 0; white-space: pre-wrap; overflow-x: auto;
}
pre.gx-code.gxv3-sol { margin-top: 10px; white-space: pre-wrap; }

/* ---- narrow screens ---- */
@media (max-width: 30em) {
  .gxv3-vrow { grid-template-columns: 42px 1fr; }
  .gxv3-vrow .v-note { grid-column: 1 / -1; }
  .gxv3-scorecard .sc-row { grid-template-columns: 80px 1fr 36px; }
  .gxv3-after .w-btn { flex: 1 1 100%; }
  .gxv3-deeprow .w-btn { flex: 1; }
}

/* ============================================================
   DOCK REFERENCE PANE — glossary detail in the right dock
   ============================================================ */
.dock-ref { padding: 24px; }
.dock-ref .dr-term {
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 16px;
  padding-bottom: 14px; border-bottom: 1px solid var(--hairline);
}
.dock-ref .dr-def { font-size: 15px; line-height: 1.75; color: var(--text); }
.dock-ref .dr-rel-label {
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--text-muted); margin: 24px 0 10px;
}
.dock-ref .dr-rel { display: flex; flex-wrap: wrap; gap: 6px; }
.dock-ref .dock-rel {
  font-family: var(--font-mono); font-size: 11px; color: var(--text-secondary);
  background: var(--accent-05); border: 1px solid var(--hairline); border-radius: 4px;
  padding: 5px 9px; cursor: pointer;
  transition: color 0.2s ease-in-out, border-color 0.2s ease-in-out, background 0.2s ease-in-out;
}
.dock-ref .dock-rel:hover { color: var(--accent); border-color: var(--accent-deep); background: var(--accent-10); }

/* ============================================================
   LESSON PLAYER (Learn mode) — view layer over chapter HTML
   ============================================================ */
body.learn-mode .chapter-grid,
body.learn-mode .chapter-hero { display: none; }
.lesson-view { display: none; }
body.learn-mode .lesson-view { display: block; }

.lesson-view { max-width: 1320px; margin: 0 auto; padding: 84px 24px 0; }
.lv-top { display: flex; align-items: baseline; gap: 16px; margin-bottom: 18px; flex-wrap: wrap; }
.lv-top .le { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.22em; color: var(--accent); text-transform: uppercase; }
.lv-top .lt { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em; color: var(--text-muted); text-transform: uppercase; }
.lv-top .spacer { flex: 1; }
.lv-top .view-toggle { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.14em; color: var(--text-secondary); text-transform: uppercase; border: 1px solid var(--hairline); padding: 7px 11px; border-radius: 4px; cursor: pointer; background: none; transition: color .2s, border-color .2s; }
.lv-top .view-toggle:hover { color: var(--accent); border-color: var(--accent-deep); }

.lv-split { display: grid; grid-template-columns: 1.32fr 1fr; gap: 28px; align-items: start; }
@media (max-width: 59.9375em) { .lv-split { grid-template-columns: 1fr; } }

.lv-stage { border: 1px solid var(--border-strong); border-radius: 4px; background: #000; overflow: hidden; position: sticky; top: 84px; }
@media (max-width: 59.9375em) { .lv-stage { position: static; } }
.lv-stage-tabs { display: flex; gap: 2px; padding: 10px 12px; border-bottom: 1px solid var(--hairline); background: var(--panel); flex-wrap: wrap; }
.lv-stage-tabs button { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-muted); background: none; border: 1px solid transparent; border-radius: 4px; padding: 8px 13px; cursor: pointer; display: inline-flex; align-items: center; gap: 7px; transition: color .2s, border-color .2s, background .2s; }
.lv-stage-tabs button:hover { color: var(--text-secondary); }
.lv-stage-tabs button.on { color: var(--accent); border-color: var(--hairline); background: var(--accent-05); }
.lv-stage-tabs .spacer { flex: 1; }
.lv-stage-body { position: relative; min-height: 320px; }
.lv-pane { display: none; padding: 20px; }
.lv-pane.on { display: block; }
.lv-pane.lv-pane-media { padding: 0; }   /* video/figure flush */
.lv-stage-body .widget, .lv-stage-body .pycell, .lv-stage-body .figure { margin: 0; }

.lv-video { width: 100%; display: block; background: #000; aspect-ratio: 16/9; }
.lv-video-wrap { position: relative; }
.lv-video-pending {
  aspect-ratio: 16/9; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 14px;
  background:
    linear-gradient(rgba(47,50,52,.20) 1px, transparent 1px),
    linear-gradient(90deg, rgba(47,50,52,.20) 1px, transparent 1px), #000;
  background-size: 28px 28px, 28px 28px, auto;
}
.lv-video-pending .vp-dot { width: 8px; height: 8px; background: var(--accent); animation: pulse 2.4s ease-in-out infinite; }
.lv-video-pending .vp-t { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--text-muted); }

.lv-panel { min-width: 0; }
.lv-panel > .section { padding: 0 !important; border: 0 !important; }
.lv-panel .sec-head { margin-bottom: 20px; }
.lv-panel .eq { overflow-x: auto; }

.lv-rail { display: flex; align-items: center; gap: 16px; margin: 40px 0 72px; padding-top: 22px; border-top: 1px solid var(--hairline); }
.lv-rail .dots { display: flex; gap: 7px; flex: 1; flex-wrap: wrap; }
.lv-rail .dot { width: 26px; height: 4px; background: var(--hairline); border-radius: 2px; cursor: pointer; transition: background .2s; }
.lv-rail .dot.done { background: var(--accent-deep); }
.lv-rail .dot.on { background: var(--accent); }
.lv-rail .nav { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-secondary); border: 1px solid var(--hairline); padding: 10px 16px; border-radius: 4px; cursor: pointer; background: none; transition: color .2s, border-color .2s, background .2s; }
.lv-rail .nav:hover { color: var(--text-bright); border-color: var(--border-strong); }
.lv-rail .nav.next { background: var(--accent); color: #000; border-color: var(--accent); }
.lv-rail .nav.next:hover { opacity: .9; color: #000; }
.lv-rail .nav[disabled] { opacity: .35; pointer-events: none; }

/* ============================================================
   WRITE-THE-VALUE EXERCISE artifact (works in Read + Learn)
   ============================================================ */
.exercise { border: 1px solid var(--border-strong); border-radius: 4px; background: #000; margin: 28px 0; overflow: hidden; }
.exercise .ex-head { display: flex; align-items: center; gap: 10px; padding: 11px 18px; background: var(--panel); border-bottom: 1px solid var(--hairline); font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--accent); }
.exercise .ex-head .ex-tag { margin-left: auto; color: var(--text-muted); }
.exercise .ex-body { padding: 18px; }
.exercise .ex-q { font-size: 15px; line-height: 1.65; color: var(--text); margin-bottom: 16px; }
.exercise .ex-q .katex { font-size: 1em; }
.exercise .ex-row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.exercise .ex-input { background: #000; border: 1px solid var(--hairline); border-radius: 4px; color: var(--text-bright); font-family: var(--font-mono); font-size: 14px; padding: 10px 13px; width: 150px; transition: border-color .2s; }
.exercise .ex-input:focus { outline: none; border-color: var(--accent); }
.exercise .ex-input.right { border-color: var(--accent); color: var(--accent); }
.exercise .ex-input.wrong { border-color: var(--danger); color: var(--danger); }
.exercise .ex-unit { font-family: var(--font-mono); font-size: 13px; color: var(--text-muted); }
.exercise .ex-actions { display: flex; gap: 10px; margin-left: auto; }
.exercise .ex-link { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-secondary); background: none; border: 0; cursor: pointer; padding: 6px; }
.exercise .ex-link:hover { color: var(--accent); }
.exercise .ex-feedback { margin-top: 14px; font-size: 13px; line-height: 1.6; display: none; }
.exercise .ex-feedback.show { display: block; }
.exercise .ex-feedback.ok { color: var(--accent); }
.exercise .ex-feedback.no { color: var(--danger); }
.exercise .ex-reveal { margin-top: 14px; padding: 14px 16px; border-left: 2px solid var(--accent); background: var(--accent-05); font-size: 13px; line-height: 1.65; color: var(--text-secondary); display: none; }
.exercise .ex-reveal.show { display: block; }
.exercise .ex-reveal b { color: var(--text-bright); }
.exercise .ex-reveal .katex { color: var(--text); }

/* moved content must never inherit GSAP's from-state opacity:0 */
.lesson-view [data-reveal], .lesson-view [data-reveal-stagger],
.lesson-view [data-reveal-stagger] > * { opacity: 1 !important; transform: none !important; }

/* ============================================================
   LANDING — start/continue band, volume spine, routed paths
   ============================================================ */
.start-band { border-top: 1px solid var(--hairline); border-bottom: 1px solid var(--hairline); background: linear-gradient(180deg, rgba(43,89,69,0.10), rgba(0,0,0,0)), #000; }
.start-band .shell { padding-top: 56px; padding-bottom: 56px; }
.start-band .idx-eyebrow { margin-bottom: 16px; }
.start-band h2 { font-family: var(--font-display); font-weight: 700; font-size: clamp(26px, 4vw, 44px); letter-spacing: -0.02em; color: var(--text-bright); line-height: 1.08; margin-bottom: 16px; max-width: 20ch; }
.start-band .sb-sub { font-size: 16px; color: var(--text-secondary); max-width: 64ch; margin-bottom: 28px; }
.sb-cta { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-bottom: 36px; }
.sb-go { font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.12em; text-transform: uppercase; background: var(--accent); color: #000; padding: 15px 26px; border-radius: 4px; text-decoration: none; white-space: nowrap; transition: opacity .2s ease-in-out; }
.sb-go:hover { opacity: 0.88; }
.sb-ghost { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-secondary); border: 1px solid var(--hairline); padding: 14px 20px; border-radius: 4px; text-decoration: none; white-space: nowrap; transition: color .2s, border-color .2s; }
.sb-ghost:hover { color: var(--accent); border-color: var(--accent-deep); }
.sb-prog { display: flex; align-items: center; gap: 12px; }
.sb-bar-track { width: 160px; height: 4px; background: var(--hairline); border-radius: 2px; overflow: hidden; }
.sb-bar-fill { height: 100%; width: 0; background: var(--accent); transition: width .6s var(--ease-expo); }
.sb-bar-label { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-muted); white-space: nowrap; }

.sb-spine { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; margin-bottom: 22px; }
.sb-spine .sp { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.04em; color: var(--text-secondary); text-decoration: none; border: 1px solid var(--hairline); padding: 8px 12px; border-radius: 4px; transition: color .2s, border-color .2s, background .2s; white-space: nowrap; }
.sb-spine .sp:hover { color: var(--accent); border-color: var(--accent-deep); background: var(--accent-05); }
.sb-spine .sp .sp-v { color: var(--accent); }
.sb-spine .sp.gym { border-color: var(--accent-deep); color: var(--accent); }
.sb-spine .sp-arr { color: var(--text-muted); font-family: var(--font-mono); font-size: 11px; }
.sb-note { font-size: 13px; color: var(--text-muted); max-width: 70ch; }
.sb-note b { color: var(--text-secondary); font-weight: 400; }

/* routed path cards */
a.how-card { display: block; text-decoration: none; }
a.how-card .h-go { margin-top: 14px; font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); display: flex; align-items: center; gap: 8px; transition: gap .2s var(--ease-expo); }
a.how-card:hover .h-go { gap: 14px; }
a.how-card .h-go .lvl { margin-left: auto; }

/* ============================================================
   LESSON STAGE — Watch → Play → Try progression chrome
   ============================================================ */
.lv-tab-arrow { color: var(--text-muted); font-family: var(--font-mono); font-size: 12px; align-self: center; padding: 0 2px; }
.lv-stage-tabs .lv-tab-check { color: var(--accent); font-size: 9px; margin-right: 5px; opacity: 0; width: 0; display: inline-block; transition: opacity .2s, width .2s; }
.lv-stage-tabs button.visited .lv-tab-check { opacity: 1; width: auto; }
.lv-stage-tabs button.lv-next { border-color: var(--accent-deep); color: var(--accent); animation: lvNextPulse 1.8s ease-in-out infinite; }
@keyframes lvNextPulse { 0%,100% { box-shadow: 0 0 0 0 rgba(166,242,204,0); } 50% { box-shadow: 0 0 0 3px rgba(166,242,204,0.12); } }
.lv-stage-hint { padding: 9px 14px; border-bottom: 1px solid var(--hairline); background: rgba(166,242,204,0.03); font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.08em; color: var(--text-muted); text-transform: uppercase; }
.lv-stage-foot { display: flex; justify-content: flex-end; padding: 12px 14px; border-top: 1px solid var(--hairline); background: var(--panel); }
.lv-nextstep { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase; background: var(--accent-05); color: var(--accent); border: 1px solid var(--accent-deep); border-radius: 4px; padding: 9px 16px; cursor: pointer; transition: background .2s, color .2s; }
.lv-nextstep:hover { background: var(--accent); color: #000; }