/* ==========================================================================
   Dive into Staleness Analysis in Asynchronous RL — research blog stylesheet
   --------------------------------------------------------------------------
   Design system: editorial research article (matches handbook_blog + lhtb_blog).
   Warm paper background, serif display + serif body (Source Serif 4),
   Inter for UI/captions, hairline borders, one blue accent plus sienna
   (behavior/reward) and graphite (implementation) as figure semantics.

   Sections:
     0. Tokens + dark theme
     1. Base & typography
     2. Chrome: progress bar, topbar, TOC, layout
     3. Hero + TL;DR
     4. Article content: sections, notes, figures, asides
     5. Components: unit card, formula card, math boxes, steps
     6. Insights, takeaways, footer, reveal, responsive
   ========================================================================== */

/* ============================ 0. TOKENS ================================= */
:root {
  --bg:        #faf9f6;
  --surface:   #fdfcfa;
  --ink:       #201d18;
  --ink-soft:  #4a463f;
  --muted:     #6f6a61;
  --faint:     #8d887e;
  --line:      #e6e2d8;
  --line-soft: #efece4;
  --code-bg:   #f2f0e9;

  --accent:      #2a78d6;
  --accent-ink:  #1c5cab;
  --accent-wash: #eaf1fb;

  --sienna:      #bd5f16;
  --sienna-ink:  #9a4a0b;
  --sienna-wash: #f9efe3;

  --graphite:      #57534a;
  --graphite-wash: #f0eee7;

  --c-good:     #0a700a;
  --c-warn:     #bd5f16;

  /* Chart entity colors (CVD-validated, light surface). One hue per method,
     used consistently across every bar chart, line chart and legend. */
  --ch-r3:      #3c85dd;   /* R3 — blue        */
  --ch-dppo:    #cc6670;   /* DPPO — crimson   */
  --ch-satr:    #c97a3a;   /* SATR — sienna    */
  --ch-satr-r3: #9a7fd6;   /* SATR + R3 — violet */
  --ch-tis:     #7d9a3e;   /* TIS — moss green */
  --ch-base:    #8f8a80;   /* GRPO / GSPO baselines — neutral */
  --collapse-red: #e06c6c; /* collapse annotations in static figures */

  --font-serif: "Source Serif 4", "Iowan Old Style", Georgia, "Times New Roman", serif;
  --font-sans:  "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono:  "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --text-body: 17px;
  --lh-body:   1.72;

  --col:      720px;
  --col-wide: 960px;
  --toc-w:    250px;
  --radius:   10px;
  --radius-sm: 7px;
}

html.dark {
  --bg:        #131311;
  --surface:   #1a1a18;
  --ink:       #eae8e1;
  --ink-soft:  #c3c0b6;
  --muted:     #9b968b;
  --faint:     #7c786e;
  --line:      #2b2a26;
  --line-soft: #23221f;
  --code-bg:   #22211d;

  --accent:      #4e92e6;
  --accent-ink:  #86b6ef;
  --accent-wash: #1a2434;

  --sienna:      #d17c40;
  --sienna-ink:  #dd9a62;
  --sienna-wash: #2d2115;

  --graphite:      #a29d92;
  --graphite-wash: #24231f;

  --c-good: #3cb453;
  --c-warn: #d17c40;

  /* Chart entity colors (CVD-validated, dark surface) */
  --ch-r3:      #3c85dd;
  --ch-dppo:    #cc6670;
  --ch-satr:    #c97a3a;
  --ch-satr-r3: #9a7fd6;
  --ch-tis:     #7d9a3e;
  --ch-base:    #8f8a80;
  --collapse-red: #e06c6c;
}

/* ---------------------- i18n: EN / ZH block switching ------------------- */
/* Every translated block carries lang="en" or lang="zh"; the root's
   data-lang decides which set is visible. Default (no attr) = English. */
html[data-lang="zh"] [lang="en"] { display: none !important; }
html:not([data-lang="zh"]) [lang="zh"] { display: none !important; }

html[data-lang="zh"] {
  --font-serif: "Source Serif 4", "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "STSong", Georgia, serif;
  --font-sans:  "Inter", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Microsoft YaHei", ui-sans-serif, system-ui, sans-serif;
  --lh-body: 1.95;
}
html[data-lang="zh"] .hero__title { line-height: 1.22; letter-spacing: 0; }
html[data-lang="zh"] .hero__dek   { font-style: normal; }
html[data-lang="zh"] .closing     { font-style: normal; }
html[data-lang="zh"] em, html[data-lang="zh"] i { font-style: normal; font-weight: 550; }

.icon-btn.icon-btn--lang {
  width: auto; min-width: 42px; padding: 0 11px;
  font-family: var(--font-sans); font-size: 12.5px; font-weight: 650;
  color: var(--ink-soft); letter-spacing: .02em; white-space: nowrap;
}

/* ============================ 1. BASE =================================== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-serif);
  font-size: var(--text-body);
  line-height: var(--lh-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background .25s ease, color .25s ease;
}

h1, h2, h3, h4 { font-family: var(--font-serif); color: var(--ink); line-height: 1.22; margin: 0; font-weight: 600; }
p { margin: 0 0 1.25em; }
a { color: var(--accent-ink); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
em, i { font-style: italic; }
b, strong { font-weight: 600; }
code {
  font-family: var(--font-mono);
  font-size: .82em;
  background: var(--code-bg);
  padding: .1em .35em;
  border-radius: 4px;
  color: var(--ink-soft);
}
::selection { background: color-mix(in srgb, var(--accent) 22%, transparent); }

.u-b { color: var(--sienna-ink); font-weight: 600; }
.u-h { color: var(--accent-ink); font-weight: 600; }
.u-i { color: var(--graphite); font-weight: 600; }
.async-summary__lead {
  position: relative;
  --note-gap: 42px;
  max-width: var(--col);
  margin: 0 auto 1.25em;
}
.async-summary__lead p:last-of-type { margin-bottom: 0; }
.async-summary__trigger {
  display: inline;
  padding: 0 .14em .04em;
  border: 0;
  border-radius: 6px;
  background: none;
  background-image: linear-gradient(to top, color-mix(in srgb, #f4dc8a 58%, transparent) 0 42%, transparent 42% 100%);
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
  font: inherit;
  color: inherit;
  text-align: inherit;
  cursor: pointer;
}
.async-summary__trigger:hover,
.async-summary__trigger:focus-visible {
  text-decoration: none;
}
.async-summary__trigger[aria-pressed="true"] {
  background-image: linear-gradient(to top, color-mix(in srgb, #f4dc8a 72%, transparent) 0 48%, transparent 48% 100%);
}
.async-summary__note {
  top: 2px;
}
.async-summary__lead.note--fit:has(.async-summary__trigger:hover) .async-summary__note,
.async-summary__lead.note--fit:has(.async-summary__trigger:focus-visible) .async-summary__note,
.async-summary__lead.note--fit .async-summary__note:hover,
.async-summary__lead.note--fit .async-summary__note:focus-within,
.async-summary__lead.note--active .async-summary__note {
  border-left-color: color-mix(in srgb, var(--accent-ink) 52%, var(--line));
}

/* ============================ 2. CHROME ================================= */
.progress-bar {
  position: fixed; top: 0; left: 0; height: 2px; width: 0%;
  background: var(--accent);
  z-index: 100;
}

.topbar {
  position: sticky; top: 0; z-index: 60;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.topbar__inner {
  max-width: 1220px; margin: 0 auto; padding: 10px 28px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.topbar__brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-family: var(--font-serif); font-weight: 600; font-size: 16px; }
.topbar__brand:hover { text-decoration: none; }
.topbar__brand img { height: 22px; width: auto; display: block; }
.topbar__nav { display: flex; align-items: center; gap: 18px; }
.topbar__link { font-family: var(--font-sans); font-size: 13.5px; font-weight: 500; color: var(--muted); }
.topbar__link:hover { color: var(--ink); text-decoration: none; }
.topbar__link--cta {
  color: var(--accent-ink);
  border: 1px solid color-mix(in srgb, var(--accent) 36%, var(--line));
  padding: 5px 13px; border-radius: 999px;
}
.topbar__link--cta:hover { background: var(--accent-wash); }
.topbar__link--github {
  color: #1f6feb;
  border-color: color-mix(in srgb, #1f6feb 45%, var(--line));
}
.topbar__link--github:hover { background: color-mix(in srgb, #1f6feb 12%, transparent); }

.icon-btn {
  display: grid; place-items: center; width: 34px; height: 34px;
  border: 1px solid var(--line); border-radius: 9px; background: transparent;
  color: var(--ink-soft); cursor: pointer; transition: background .2s;
}
.icon-btn:hover { background: var(--line-soft); }
.icon-btn svg { stroke: currentColor; stroke-width: 1.7; fill: none; stroke-linecap: round; }
.icon-moon { display: none; }
html.dark .icon-sun  { display: none; }
html.dark .icon-moon { display: block; }

/* Layout grid: TOC + article */
.layout {
  max-width: 1220px; margin: 0 auto; padding: 0 28px;
  display: grid; grid-template-columns: var(--toc-w) minmax(0, 1fr);
  gap: 52px; align-items: start;
}
.toc { position: sticky; top: 82px; padding-top: 56px; max-height: calc(100vh - 96px); overflow-y: auto; }
.toc__title {
  font-family: var(--font-sans); font-size: 11px; font-weight: 650; letter-spacing: .12em;
  text-transform: uppercase; color: var(--faint); margin: 0 0 14px;
}
.toc__nav { display: flex; flex-direction: column; border-left: 1px solid var(--line); counter-reset: toc; }
.toc__item {
  font-family: var(--font-sans); font-size: 13px; line-height: 1.45; color: var(--muted);
  padding: 7px 14px; margin-left: -1px; border-left: 2px solid transparent;
  transition: color .15s, border-color .15s; counter-increment: toc;
}
.toc__item::before { content: counter(toc, decimal-leading-zero) "  "; font-size: 11px; color: var(--faint); font-variant-numeric: tabular-nums; }
.toc__item:hover { color: var(--ink); text-decoration: none; }
.toc__item.is-active { color: var(--accent-ink); border-left-color: var(--accent); }
.toc__item.is-active::before { color: var(--accent-ink); }

.article { padding: 56px 0 90px; min-width: 0; }
.article > section > *,
.article > footer > * { max-width: var(--col); margin-left: auto; margin-right: auto; }
.article > section > .figure--wide,
.article > section > .hero__figure,
.article > section > .math--wide,
.article > section > .aside--wide,
.article > section > .callout--wide { max-width: var(--col-wide); }
.hero > .hero__figure { max-width: var(--col-wide); }

/* ============================ 3. HERO + TLDR ============================ */
.hero { padding: 20px 0 4px; }
.hero__kicker {
  font-family: var(--font-sans); font-size: 12px; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase; color: var(--sienna-ink);
  margin: 0 0 20px;
}
.hero__title-row { display: flex; align-items: center; gap: 18px; margin: 0 0 12px; }
.hero__logo { height: 46px; width: auto; display: block; flex: none; }
.hero__title {
  font-size: clamp(34px, 4.9vw, 52px); font-weight: 600; letter-spacing: -.018em;
  line-height: 1.05; margin: 0;
}
.hero__dek {
  font-size: clamp(18px, 2.1vw, 22px); line-height: 1.4; color: var(--ink-soft);
  font-style: italic; margin: 0 0 22px;
}
.hero__subtitle-wrap {
  position: relative;
  --note-gap: 28px;
  margin: 0 0 26px;
}
.hero__subtitle-copy { min-width: 0; }
.hero__subtitle { font-size: 18px; line-height: 1.65; color: var(--ink-soft); margin: 0 0 26px; }
.hero__subtitle:last-child { margin-bottom: 0; }
.hero__note {
  position: absolute;
  top: 8px;
  left: calc(100% + var(--note-gap));
  width: 150px;
  margin-top: 0;
  padding: 10px 0 0 18px;
  border-left: 1.5px solid color-mix(in srgb, var(--accent) 24%, var(--line));
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateX(8px);
  transition: opacity .18s ease, transform .18s ease, border-left-color .2s ease;
}
.hero__subtitle-wrap.note--fit.note--open .hero__note {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
}
.hero__subtitle-wrap.note--fit.note--open:has(.hero__formula-link:hover) .hero__note,
.hero__subtitle-wrap.note--fit.note--open:has(.hero__formula-link:focus-visible) .hero__note,
.hero__subtitle-wrap.note--fit.note--open .hero__note:hover,
.hero__subtitle-wrap.note--fit.note--open .hero__note:focus-within {
  border-left-color: color-mix(in srgb, var(--accent-ink) 52%, var(--line));
}
.hero__note-label {
  margin: 0 0 8px;
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
}
.hero__note-link {
  display: block;
  font-family: var(--font-sans);
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ink-soft);
}
.hero__note-link:hover {
  color: var(--ink);
  text-decoration: none;
}
.hero__formula-link {
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}
.hero__formula-link:hover,
.hero__formula-link:focus-visible {
  text-decoration: none;
}
.hero__formula-link[aria-expanded="true"] .u-h-formula {
  background-image: linear-gradient(to top, color-mix(in srgb, #f4dc8a 72%, transparent) 0 48%, transparent 48% 100%);
}
.u-h-formula {
  display: inline;
  padding: 0 .12em .04em;
  border-radius: 6px;
  background-image: linear-gradient(to top, color-mix(in srgb, #f4dc8a 58%, transparent) 0 42%, transparent 42% 100%);
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
}

/* --- Work-in-Progress banner (sits between subtitle and byline) --- */
/* Hang the pulsing dot in the left margin so the "Work in Progress" text
   is flush-left with the preceding paragraph. Offset = padding-left + dot + gap. */
.hero__wip {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-sans); font-size: 12.5px; font-weight: 550;
  letter-spacing: .04em; color: #8a5a12;
  background: color-mix(in srgb, #f4c26b 22%, var(--surface));
  border: 1px solid color-mix(in srgb, #d99a2a 45%, var(--line));
  border-radius: 999px;
  padding: 6px 14px 6px 12px;
  margin: -8px 0 26px calc(-1 * (12px + 8px + 10px));
}
.hero__wip::before {
  content: ""; width: 8px; height: 8px; border-radius: 50%;
  background: #d99a2a;
  box-shadow: 0 0 0 0 color-mix(in srgb, #d99a2a 70%, transparent);
  animation: wipPulse 1.8s ease-out infinite;
}
.hero__wip em { font-style: normal; color: color-mix(in srgb, #8a5a12 80%, var(--ink)); font-weight: 500; }
@keyframes wipPulse {
  0%   { box-shadow: 0 0 0 0   color-mix(in srgb, #d99a2a 70%, transparent); }
  70%  { box-shadow: 0 0 0 8px color-mix(in srgb, #d99a2a 0%, transparent); }
  100% { box-shadow: 0 0 0 0   color-mix(in srgb, #d99a2a 0%, transparent); }
}
@media (prefers-reduced-motion: reduce) {
  .hero__wip::before { animation: none; }
}

.hero__byline {
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  padding: 14px 0; margin-bottom: 36px;
}
.authors { font-family: var(--font-sans); font-size: 13.5px; font-weight: 550; color: var(--ink); margin: 0 0 4px; }
.affils  { font-family: var(--font-sans); font-size: 12.5px; color: var(--muted); margin: 0; }

.tldr {
  margin: 48px auto; padding: 26px 0 8px;
  border-top: 2px solid var(--ink); border-bottom: 1px solid var(--line);
}
.tldr__kicker {
  font-family: var(--font-sans); font-size: 11.5px; font-weight: 650; letter-spacing: .12em;
  text-transform: uppercase; color: var(--faint); margin: 0 0 16px;
}
.tldr__list { list-style: none; counter-reset: tldr; margin: 0; padding: 0; display: grid; gap: 14px; }
.tldr__list li { position: relative; padding-left: 34px; counter-increment: tldr; color: var(--ink-soft); margin-bottom: 10px; }
.tldr__list li::before {
  content: counter(tldr);
  position: absolute; left: 0; top: .22em;
  font-family: var(--font-sans); font-size: 12px; font-weight: 650;
  width: 21px; height: 21px; border-radius: 50%;
  display: grid; place-items: center;
  color: var(--accent-ink); border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--line));
}

/* ============================ 4. CONTENT ================================ */
.section { padding: 60px 0 10px; scroll-margin-top: 80px; }
.section__num {
  font-family: var(--font-sans); font-size: 12px; font-weight: 650;
  letter-spacing: .14em; text-transform: uppercase; color: var(--accent-ink);
  margin: 0 0 10px;
}
.section__title { font-size: clamp(26px, 3.2vw, 33px); font-weight: 600; letter-spacing: -.012em; margin: 0 0 .75em; }
.subhead { font-size: 21px; font-weight: 600; margin: 2.1em 0 .65em; }
.subhead--result { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.subhead__tag {
  font-family: var(--font-sans); font-size: 11.5px; font-weight: 650; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent-ink);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--line));
  padding: 3px 10px; border-radius: 999px; white-space: nowrap;
}
.subhead__tag--warn {
  color: var(--sienna-ink);
  border-color: color-mix(in srgb, var(--sienna) 45%, var(--line));
}
.subhead--methods { font-size: 24px; margin-top: 2.6em; }

/* Margin-note callout */
.note {
  margin: 30px auto; padding: 4px 0 4px 22px;
  border-left: 2px solid var(--accent);
}
.note__label {
  font-family: var(--font-sans); font-size: 11.5px; font-weight: 650; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent-ink); margin: 0 0 6px;
}
.note--warn { border-left-color: var(--sienna); }
.note--warn .note__label { color: var(--sienna-ink); }
.note p:last-child { margin-bottom: 0; color: var(--ink-soft); font-size: 16px; line-height: 1.65; }

/* Figures */
.figure { margin: 36px auto; }
.figure img { display: block; width: 100%; height: auto; border-radius: var(--radius-sm); }
figcaption {
  font-family: var(--font-sans); font-size: 13px; line-height: 1.55; color: var(--muted);
  margin: 14px auto 0; max-width: var(--col);
}
figcaption b { color: var(--ink-soft); font-weight: 600; }

/* Sub-figure grid (used to split a wide multi-panel figure into per-method panels
   so that in-panel typography stays legible at article width). */
.figure__grid {
  display: grid; gap: 18px 20px; margin: 8px 0 0;
}
.figure__grid--2x2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.figure__grid .subfigure { margin: 0; }
.figure__grid .subfigure img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--surface);
}
.figure__grid .subfigure figcaption {
  margin: 8px 0 0; font-size: 12.5px; text-align: center;
}
.figure__grid .subfigure figcaption b { letter-spacing: .02em; }
@media (max-width: 720px) {
  .figure__grid--2x2 { grid-template-columns: 1fr; }
}

/* Compact variants used inside <details class="aside"> panels, where the
   surrounding column is narrower and figures should not dominate the proof. */
.figure__grid--in-aside {
  gap: 12px 14px; margin: 10px 0 4px;
}
.figure__grid--in-aside .subfigure img {
  border-color: color-mix(in srgb, var(--line) 90%, transparent);
}
.figure__grid--in-aside .subfigure figcaption {
  font-size: 11.5px; line-height: 1.45;
}
.subfigure--inline {
  margin: 14px auto 6px;
  max-width: 560px;
}
.subfigure--inline img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: var(--surface);
}
.subfigure--inline figcaption {
  margin: 8px auto 0; text-align: center;
  font-size: 12.5px; line-height: 1.55; color: var(--muted);
}
.subfigure--inline figcaption b { color: var(--ink-soft); font-weight: 600; }

/* Expandable aside (used heavily in Section 4 for full proofs) */
.aside {
  margin: 28px auto; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); overflow: hidden;
}
.aside > summary {
  cursor: pointer; list-style: none; padding: 14px 20px;
  font-family: var(--font-sans); font-weight: 600; font-size: 14.5px; color: var(--ink);
  display: flex; align-items: center; gap: 10px;
  transition: background .15s;
}
.aside > summary:hover { background: var(--line-soft); }
.aside > summary::-webkit-details-marker { display: none; }
.aside > summary::before {
  content: ""; width: 7px; height: 7px; border-right: 1.6px solid var(--muted); border-bottom: 1.6px solid var(--muted);
  transform: rotate(-45deg); transition: transform .2s; flex: none;
}
.aside[open] > summary::before { transform: rotate(45deg); }
.aside > *:not(summary) { padding: 0 20px 16px; }
.aside p { color: var(--ink-soft); font-size: 15.5px; line-height: 1.65; }
.aside__tag {
  font-family: var(--font-sans); font-size: 10.5px; font-weight: 650; letter-spacing: .11em;
  text-transform: uppercase; color: var(--accent-ink);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--line));
  padding: 2px 9px; border-radius: 999px; margin-right: 8px;
}

/* --- Figure-hosting aside (collapsible <details> that wraps a single figure) --- */
.aside--figure > summary {
  font-weight: 550; font-size: 13.8px; color: var(--ink-soft);
}
.aside--figure > summary b { color: var(--ink); font-weight: 650; }
.aside--figure > figure.subfigure--inline {
  margin: 6px auto 10px;
  padding: 0 20px;
}
.aside--figure > figure.subfigure--inline img { margin-inline: auto; }
.aside__tag--figure {
  color: var(--sienna-ink, var(--accent-ink));
  border-color: color-mix(in srgb, var(--sienna, var(--accent)) 45%, var(--line));
  background: color-mix(in srgb, var(--sienna, var(--accent)) 8%, transparent);
}

/* --- Nested aside / callout: visually narrower than their parent aside --- */
.aside .aside,
.aside .callout {
  margin-left: 18px;
  margin-right: 18px;
  width: auto;
}
.aside .aside { margin-top: 18px; margin-bottom: 18px; }
.aside .callout { margin-top: 20px; margin-bottom: 20px; }

/* --- Setup aside: keep summary full-width, but constrain the opened body
       to a callout-like reading measure instead of the wider article column. */
.aside--setup-measure > .aside__body--callout-measure {
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================ 5. COMPONENTS ============================= */
/* --- Symbol dictionary card --- */
.symlist {
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface);
  padding: 6px 0; margin: 24px auto;
  font-family: var(--font-sans);
}
.symlist dl { margin: 0; display: grid; grid-template-columns: 200px 1fr; gap: 0 22px; }
.symlist dt {
  padding: 10px 22px; border-bottom: 1px solid var(--line-soft);
  font-family: var(--font-serif); font-size: 15px; color: var(--ink); font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.symlist dd {
  padding: 10px 22px 10px 0; border-bottom: 1px solid var(--line-soft);
  font-size: 13.5px; color: var(--ink-soft); line-height: 1.6; margin: 0;
}
.symlist dl > *:nth-last-child(-n+2) { border-bottom: none; }

/* --- Formula callout box (boxed key equations) --- */
.callout {
  margin: 26px auto; padding: 20px 24px 18px;
  border: 1px solid color-mix(in srgb, var(--accent) 32%, var(--line));
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--accent-wash) 55%, var(--surface));
  /* Do NOT set `overflow:hidden` — that stops inner mjx-container[display="true"]
     from showing its own horizontal scrollbar on wide equations. */
}
.callout__label {
  font-family: var(--font-sans); font-size: 10.5px; font-weight: 650; letter-spacing: .11em;
  text-transform: uppercase; color: var(--accent-ink); margin: 0 0 8px;
}
.callout p:last-child { margin-bottom: 0; }

.callout--warn {
  border-color: color-mix(in srgb, var(--sienna) 40%, var(--line));
  background: color-mix(in srgb, var(--sienna-wash) 55%, var(--surface));
}
.callout--warn .callout__label { color: var(--sienna-ink); }

/* --- Horizontal scroll for long display equations (MathJax v3) --- */
/* Applies to every $$...$$ / \[...\] block globally: if the rendered SVG
   exceeds the container width, a horizontal scrollbar appears instead of
   overflowing (which used to poke out of the blue callout boxes). */
mjx-container[display="true"] {
  display: block !important;
  width: 100% !important;
  min-width: 0 !important;
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 4px 2px 8px;   /* leave room for scrollbar without clipping subscripts */
  scrollbar-width: thin;
}
mjx-container[display="true"]::-webkit-scrollbar { height: 6px; }
mjx-container[display="true"]::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--ink-soft) 35%, transparent);
  border-radius: 3px;
}
/* Inside a callout, keep the equation strictly bounded by the callout's inner width
   so the horizontal scrollbar activates instead of the equation poking outside. */
.callout mjx-container[display="true"] {
  margin: 0;
  max-width: 100%;
  width: 100%;
}
.callout {
  /* re-declare width behaviour explicitly (helps Safari) */
  min-width: 0;
  contain: layout paint;
}

/* --- Method cards (Section 4) --- */
.method {
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface);
  margin: 30px auto; padding: 22px 26px 18px;
  box-shadow: 0 1px 2px rgba(20,18,12,.04);
}
.method__head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; margin: 0 0 10px; }
.method__tag {
  font-family: var(--font-sans); font-size: 10.5px; font-weight: 650; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent-ink);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--line));
  padding: 2px 10px; border-radius: 999px;
}
.method__title { font-size: 20px; font-family: var(--font-serif); font-weight: 600; margin: 0; }
.method__target {
  font-family: var(--font-sans); font-size: 12.5px; color: var(--muted);
  margin: 0 0 12px; padding-bottom: 10px; border-bottom: 1px dashed var(--line);
}
.method__target b { color: var(--sienna-ink); font-weight: 650; }
.method p { font-size: 15.5px; line-height: 1.68; }
.method .aside { margin: 14px 0; }

/* --- Comparison table (methods at a glance) --- */
.cmp-table-wrap { overflow-x: auto; margin: 22px auto; }
.cmp-table {
  width: 100%; border-collapse: collapse; font-family: var(--font-sans); font-size: 13px;
  min-width: 640px;
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--surface);
}
.cmp-table thead th {
  text-align: left; font-size: 10.5px; font-weight: 650; letter-spacing: .09em;
  text-transform: uppercase; color: var(--faint);
  padding: 12px 14px; border-bottom: 1px solid var(--line);
  background: var(--line-soft);
}
.cmp-table td { padding: 11px 14px; border-bottom: 1px solid var(--line-soft); color: var(--ink-soft); vertical-align: top; }
.cmp-table tbody tr:last-child td { border-bottom: none; }
.cmp-table td:first-child { font-weight: 650; color: var(--ink); }
.cmp-table .cell-em { color: var(--accent-ink); font-weight: 650; }
.cmp-table .cell-warn { color: var(--sienna-ink); font-weight: 650; }

/* --- SATR pipeline step ladder --- */
/* Align .steps' right edge with the body column (`--col`).
   `width:100%` + `min-width:0` ensures the grid container never grows
   beyond its parent (section) or `max-width: var(--col)`, and grid items
   (`.step`) don't blow past their track width due to wide MathJax SVGs
   (which get their own horizontal scrollbar via the global rule above). */
.steps { margin: 34px auto; display: grid; gap: 0; width: 100%; max-width: var(--col); min-width: 0; }
.step { position: relative; padding: 0 0 30px 46px; min-width: 0; max-width: 100%; }
.step:last-child { padding-bottom: 4px; }
.step::before {
  content: ""; position: absolute; left: 14px; top: 34px; bottom: 0;
  width: 1px; background: var(--line);
}
.step:last-child::before { display: none; }
.step__head { display: flex; align-items: baseline; gap: 12px; margin-bottom: 8px; flex-wrap: wrap; }
.step__n {
  position: absolute; left: 0; top: 0;
  width: 29px; height: 29px; border-radius: 50%;
  display: grid; place-items: center;
  font-family: var(--font-sans); font-size: 13px; font-weight: 650;
  color: var(--accent-ink); background: var(--accent-wash);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--line));
}
.step__head h4 { font-size: 18px; font-family: var(--font-serif); margin: 0; }
.step__ref { font-family: var(--font-sans); font-size: 12px; color: var(--muted); font-weight: 550; }
.step p { margin: 0 0 .8em; color: var(--ink-soft); font-size: 15.5px; line-height: 1.66; }

/* --- Improvement-chain diagram (four nested sets) --- */
.chain {
  display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 9px;
  max-width: var(--col-wide); margin: 26px auto 8px;
  font-family: var(--font-sans); font-size: 13.5px;
}
.chain__box {
  padding: 8px 15px; border-radius: 9px; font-weight: 600; color: var(--ink-soft);
  border: 1px solid var(--line); background: var(--surface); white-space: nowrap;
}
.chain__box--satr { background: var(--accent-wash); color: var(--accent-ink); border-color: color-mix(in srgb, var(--accent) 45%, var(--line)); }
.chain__box--dppo { background: var(--sienna-wash); color: var(--sienna-ink); border-color: color-mix(in srgb, var(--sienna) 40%, var(--line)); }
.chain__arw { color: var(--faint); font-weight: 700; font-family: var(--font-serif); }

/* --- Specs strip --- */
.specs {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0;
  margin: 30px auto; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  font-family: var(--font-sans);
}
.spec { padding: 18px 20px 16px; }
.spec + .spec { border-left: 1px solid var(--line); }
.spec__label {
  font-size: 10.5px; font-weight: 650; letter-spacing: .11em; text-transform: uppercase;
  color: var(--faint); margin: 0 0 7px;
}
.spec__value { font-family: var(--font-serif); font-size: 17.5px; font-weight: 600; color: var(--ink); margin: 0 0 7px; }
.spec__note { font-size: 12.5px; color: var(--muted); line-height: 1.5; margin: 0; }

/* Tick lists */
.ticklist { list-style: none; margin: 14px 0; padding: 0; display: grid; gap: 10px; }
.ticklist li {
  position: relative; padding-left: 24px; color: var(--ink-soft);
  font-size: 15px; line-height: 1.6;
}
.ticklist li::before {
  content: ""; position: absolute; left: 2px; top: 8px; width: 8px; height: 4.5px;
  border-left: 1.8px solid var(--accent-ink); border-bottom: 1.8px solid var(--accent-ink);
  transform: rotate(-45deg);
}
.ticklist--takeaways { max-width: var(--col); margin: 8px auto 26px; gap: 14px; }
.ticklist--takeaways li { font-size: 17px; line-height: 1.65; padding-left: 28px; }
.ticklist--takeaways li::before { top: 10px; width: 9px; height: 5px; }

/* Insights */
.insights { margin: 30px auto; display: grid; gap: 0; max-width: var(--col); }
.insight {
  display: grid; grid-template-columns: 52px minmax(0, 1fr); gap: 16px; align-items: start;
  min-width: 0;
  padding: 20px 0; border-top: 1px solid var(--line);
}
.insight > * { min-width: 0; }
.insight:last-child { border-bottom: 1px solid var(--line); }
.insight__n {
  font-family: var(--font-sans); font-size: 13px; font-weight: 650;
  color: var(--faint); padding-top: 5px; font-variant-numeric: tabular-nums;
}
.insight h4 { font-size: 19px; margin: 0 0 6px; font-family: var(--font-serif); }
.insight p { color: var(--ink-soft); margin: 0; font-size: 15.5px; line-height: 1.65; }

/* Experiment placeholder */
.exp-placeholder {
  margin: 16px 0 6px; padding: 14px 18px;
  border: 1px dashed var(--line); border-radius: var(--radius-sm);
  background: var(--line-soft);
  font-family: var(--font-sans); font-size: 12.5px; color: var(--muted);
  display: flex; align-items: center; gap: 10px;
}
.exp-placeholder::before {
  content: "EXP"; font-size: 10px; font-weight: 700; letter-spacing: .12em;
  color: var(--accent-ink); background: var(--surface); border: 1px solid var(--line);
  padding: 3px 8px; border-radius: 5px; flex: none;
}

.closing {
  font-size: 18px; line-height: 1.7; color: var(--ink);
  border-top: 1px solid var(--line); padding-top: 22px; margin-top: 6px;
  font-style: italic;
}

/* ============================ 6. FOOTER + REVEAL ======================== */
.footer { border-top: 1px solid var(--line); margin-top: 70px; padding-top: 40px; }
.footer h3 { font-size: 19px; margin: 0 0 14px; }
.bibtex { position: relative; }
.bibtex pre {
  font-family: var(--font-mono); font-size: 12.5px; line-height: 1.6; color: var(--ink-soft);
  background: var(--code-bg); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 20px; overflow-x: auto; margin: 0;
}
.bibtex__copy {
  position: absolute; top: 11px; right: 11px;
  font-family: var(--font-sans); font-size: 12.5px; font-weight: 600; color: var(--accent-ink);
  background: var(--surface); border: 1px solid var(--line); border-radius: 7px;
  padding: 4px 11px; cursor: pointer;
}
.bibtex__copy:hover { background: var(--accent-wash); }

.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* MathJax display equations — soften vertical spacing */
mjx-container[display="true"] {
  margin: 1em 0 !important;
}
mjx-container { max-width: 100%; overflow-x: auto; overflow-y: hidden; }

@media (max-width: 1000px) {
  .layout { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .toc { display: none; }
  .article { padding-top: 32px; }
}
@media (max-width: 720px) {
  body { font-size: 16px; }
  .topbar__link:not(.topbar__link--cta) { display: none; }
  .specs { grid-template-columns: 1fr; }
  .spec + .spec { border-left: none; border-top: 1px solid var(--line); }
  .symlist dl { grid-template-columns: 1fr; }
  .symlist dt { padding-bottom: 2px; border-bottom: none; }
  .symlist dd { padding-left: 22px; padding-top: 0; }
  .method { padding: 18px 18px 14px; }
  .cmp-table { min-width: 520px; }
  .hero__logo { height: 34px; }
  .hero__subtitle-wrap { margin-bottom: 26px; }
}

/* ================================================================
   7. EXPERIMENT CHARTS  (bar + line, scroll-triggered animations)
   ---------------------------------------------------------------- */

.exp-figure {
  margin: 30px 0 8px;
  padding: 20px 22px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  position: relative;
}
.exp-figure__head {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 10px;
  margin: 0 0 14px;
}
.exp-figure__tag {
  font-family: var(--font-sans); font-size: 10.5px; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--accent-ink); background: var(--surface);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--line));
  padding: 3px 9px; border-radius: 5px;
}
.exp-figure__tag--satr {
  color: var(--sienna-ink);
  border-color: color-mix(in srgb, var(--sienna) 45%, var(--line));
}
.exp-figure__title {
  font-family: var(--font-sans); font-size: 15px; font-weight: 600;
  color: var(--ink); margin: 0; letter-spacing: -.005em;
}
.exp-figure__interactive {
  font-family: var(--font-sans); font-size: 9.5px; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--accent-ink); background: var(--accent-wash);
  border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--line));
  padding: 2px 9px; border-radius: 999px; align-self: center;
}
.exp-figure__cap {
  font-family: var(--font-sans); font-size: 12.5px; line-height: 1.55;
  color: var(--muted); margin: 10px 0 0;
}
.exp-cap__lead-wrap {
  position: relative;
  display: block;
  --note-gap: 42px;
}
.exp-cap__lead-trigger {
  display: inline;
  padding: 0;
  border: 0;
  background: none;
  font: inherit;
  color: inherit;
  text-align: inherit;
  cursor: pointer;
}
.exp-cap__lead-trigger:hover,
.exp-cap__lead-trigger:focus-visible {
  text-decoration: none;
}
.exp-cap__lead-trigger[aria-pressed="true"] .exp-cap__lead-highlight {
  background-image: linear-gradient(to top, color-mix(in srgb, #f4dc8a 72%, transparent) 0 48%, transparent 48% 100%);
}
.exp-cap__lead-highlight {
  display: inline;
  padding: 0 .14em .04em;
  border-radius: 6px;
  background-image: linear-gradient(to top, color-mix(in srgb, #f4dc8a 58%, transparent) 0 42%, transparent 42% 100%);
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
}
.exp-cap__note {
  position: absolute;
  top: -2px;
  left: calc(100% + var(--note-gap));
  width: 165px;
  margin: 0;
  padding: 6px 0 0 12px;
  border-left: 1.5px solid color-mix(in srgb, var(--accent) 24%, var(--line));
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateX(8px);
  transition: opacity .18s ease, transform .18s ease, border-left-color .2s ease;
}
.exp-cap__lead-wrap.note--fit .exp-cap__note {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
}
.exp-cap__lead-wrap.note--fit:has(.exp-cap__lead-trigger:hover) .exp-cap__note,
.exp-cap__lead-wrap.note--fit:has(.exp-cap__lead-trigger:focus-visible) .exp-cap__note,
.exp-cap__lead-wrap.note--fit .exp-cap__note:hover,
.exp-cap__lead-wrap.note--fit .exp-cap__note:focus-within,
.exp-cap__lead-wrap.note--active .exp-cap__note {
  border-left-color: color-mix(in srgb, var(--accent-ink) 52%, var(--line));
}
.exp-cap__note-label {
  margin: 0 0 6px;
  font-family: var(--font-sans);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
}
.exp-cap__note-link {
  display: block;
  font-family: var(--font-sans);
  font-size: 11.5px;
  line-height: 1.55;
  color: var(--ink-soft);
  text-decoration: none;
}
.exp-cap__note-link:hover {
  color: var(--ink);
  text-decoration: none;
}

.sat-proof-note-wrap {
  --note-gap: 28px;
}
.sat-proof-note {
  top: 212px;
  width: 180px;
}
.sat-proof-note-wrap.note--fit .sat-proof-note {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateX(8px);
}
.sat-proof-note-wrap.note--fit > details[open] .sat-proof-note {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
}
.sat-proof-note-wrap.note--fit:has(.sat-proof-note-trigger:hover) > details[open] .sat-proof-note,
.sat-proof-note-wrap.note--fit:has(.sat-proof-note-trigger:focus-visible) > details[open] .sat-proof-note,
.sat-proof-note-wrap.note--fit > details[open] .sat-proof-note:hover,
.sat-proof-note-wrap.note--fit > details[open] .sat-proof-note:focus-within,
.sat-proof-note-wrap.note--active > details[open] .sat-proof-note {
  border-left-color: color-mix(in srgb, var(--accent-ink) 52%, var(--line));
}

.exp-figure__cap b { color: var(--ink-soft); font-weight: 600; }
.exp-figure__cap code {
  background: var(--code-bg); border: 1px solid var(--line);
  border-radius: 4px; padding: 0 4px; font-size: 11.5px;
}

.exp-figure__legend {
  display: flex; flex-wrap: wrap; gap: 14px 20px;
  font-family: var(--font-sans); font-size: 12px;
  color: var(--ink-soft); margin: 4px 0 12px;
}
.exp-figure__legend .lg {
  display: inline-flex; align-items: center; gap: 6px;
}
.exp-figure__legend .lg::before {
  content: ""; width: 22px; height: 8px; border-radius: 2px;
  background: var(--sw, var(--accent));
}
.exp-figure__legend .lg--line::before {
  height: 2.5px; border-radius: 0;
}
/* legend swatch variants matching the bar encodings */
.exp-figure__legend .lg--hollow::before {
  background: color-mix(in srgb, var(--sw, var(--accent)) 16%, var(--surface));
  box-shadow: inset 0 0 0 1.5px var(--sw, var(--accent));
}
.exp-figure__legend .lg--collapse::before {
  background:
    repeating-linear-gradient(-45deg,
      transparent 0 3px,
      color-mix(in srgb, var(--surface) 62%, transparent) 3px 6px),
    var(--sw, var(--c-warn));
  outline: 1px dashed var(--c-warn);
  outline-offset: 1px;
}
.exp-figure__legend .lg--best::before {
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--sw, var(--sienna)) 30%, transparent);
}

/* --------  BAR CHART  -------- */
.bar-chart {
  position: relative;
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 6px 12px;
  padding: 4px 4px 0;
}
.bar-chart__y {
  position: relative;
  height: var(--chart-h, 260px);
  font-family: var(--font-sans); font-size: 10.5px;
  color: var(--muted);
}
.bar-chart__ytick {
  position: absolute;
  right: 4px;
  transform: translateY(50%);
  font-variant-numeric: tabular-nums;
}
.bar-chart__plot {
  position: relative;
  height: var(--chart-h, 260px);
  border-left: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 0 4px;
}
.bar-chart__grid {
  position: absolute; inset: 0;
  pointer-events: none;
}
.bar-chart__grid::before,
.bar-chart__grid::after {
  content: ""; position: absolute; left: 0; right: 0;
  border-top: 1px dashed color-mix(in srgb, var(--line) 65%, transparent);
}
.bar-chart__bars {
  position: relative;
  display: flex; align-items: flex-end;
  gap: 12px;
  height: 100%;
  padding: 0 6px;
}
.bar-chart__group {
  flex: 1;
  display: flex; flex-direction: column; align-items: center;
  height: 100%; position: relative;
  min-width: 0;
}
.bar-chart__group-bars {
  display: flex; align-items: flex-end;
  gap: 3px;
  width: 100%; height: 100%;
  justify-content: center;
}
.bar {
  flex: 1;
  max-width: 40px; min-width: 6px;
  height: var(--h, 0%);
  background: var(--sw, var(--accent));
  border-radius: 3px 3px 0 0;
  position: relative;
  transform: scaleY(0);
  transform-origin: bottom;
  transition: transform .9s cubic-bezier(.22, 1, .36, 1);
}
.reveal.is-in .bar,
.exp-figure.is-in .bar {
  transform: scaleY(1);
}
/* staleness encoding: s = 1 bars are hollow (tinted + ring), s = 8 bars solid */
.bar[data-stale="1"] {
  background: color-mix(in srgb, var(--sw, var(--accent)) 16%, var(--surface));
  box-shadow: inset 0 0 0 1.75px var(--sw, var(--accent));
}
/* a collapsed run keeps its method color but is striped + dash-outlined */
.bar[data-status="collapse"] {
  background:
    repeating-linear-gradient(-45deg,
      transparent 0 4px,
      color-mix(in srgb, var(--surface) 62%, transparent) 4px 8px),
    var(--sw, var(--accent));
  outline: 1.5px dashed var(--c-warn);
  outline-offset: 1.5px;
}
.bar[data-status="best"] {
  box-shadow: 0 0 0 2.5px color-mix(in srgb, var(--sw, var(--sienna)) 30%, transparent);
}
.bar[data-status="best"] .bar__val { color: var(--ink); font-weight: 700; }
.bar__val {
  position: absolute; left: 50%; top: -18px; transform: translateX(-50%);
  font-family: var(--font-sans); font-size: 10.5px; font-weight: 600;
  color: var(--ink-soft); white-space: nowrap;
  font-variant-numeric: tabular-nums;
  opacity: 0; transition: opacity .5s ease .5s;
}
.reveal.is-in .bar__val,
.exp-figure.is-in .bar__val { opacity: 1; }
.bar-chart__labels {
  display: flex; gap: 12px; padding: 6px 6px 0;
  font-family: var(--font-sans); font-size: 11px;
  color: var(--ink-soft);
}
.bar-chart__label {
  flex: 1; text-align: center;
  line-height: 1.3; min-width: 0;
  word-break: break-word;
}
.bar-chart__label small {
  display: block; font-size: 10px; color: var(--muted); margin-top: 2px;
}

/* summary (single-group) bar chart, e.g. logprob_diff averages */
.bar-chart--summary { grid-template-columns: 56px 1fr; }
.bar-chart--summary .bar-chart__group-bars { gap: 0; }
.bar-chart--summary .bar { max-width: 100%; min-width: 4px; }
.bar-chart--summary .bar-chart__labels {
  font-size: 10px; gap: 4px; padding: 2px 6px 0;
}
.bar-chart--summary .bar-chart__label { transform: rotate(-32deg) translate(-10px, -2px); transform-origin: top left; text-align: left; white-space: nowrap; }
.bar-chart--summary { padding-bottom: 80px; }
/* --------  LINE CHART  -------- */
.line-chart {
  position: relative;
  width: 100%;
  background: var(--surface);
  border-radius: var(--radius-sm);
}
.line-chart > svg {
  width: 100%; height: 500px; display: block;
  /* Anti-aliasing / anti-double-image: force geometric-precise rendering. */
  shape-rendering: geometricPrecision;
  text-rendering: geometricPrecision;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
.line-chart .lc-grid  { stroke: var(--line-soft); stroke-width: .8; fill: none; }
.line-chart .lc-frame { stroke: var(--line);      stroke-width: .8; fill: none; }
.line-chart .lc-tick  {
  font-family: var(--font-sans); font-size: 14px;
  fill: var(--muted); font-variant-numeric: tabular-nums;
}
.line-chart .lc-axlbl {
  font-family: var(--font-sans); font-size: 15px; font-weight: 500;
  fill: var(--ink-soft);
}
.line-chart .lc-path {
  fill: none; stroke-width: 3.6;
  stroke-linecap: round; stroke-linejoin: round;
  stroke-dasharray: var(--len, 4000);
  stroke-dashoffset: var(--len, 4000);
  transition: stroke-dashoffset 1.6s cubic-bezier(.22, 1, .36, 1);
  opacity: 1;
}
.reveal.is-in .lc-path,
.exp-figure.is-in .lc-path { stroke-dashoffset: 0; }

/* Entity colors: defined on the class (not scoped to .line-chart) so legend
   chips and tooltip swatches can reuse them via currentColor. */
.lc-path--satr       { color: var(--ch-satr); }
.lc-path--satr-r3    { color: var(--ch-satr-r3); }
.lc-path--satr-r3-deep { color: #7f63c9; }
.lc-path--r3         { color: var(--ch-r3); }
.lc-path--r3-gspo    { color: color-mix(in srgb, var(--ch-r3) 55%, var(--ink) 45%); }
.lc-path--tis        { color: var(--ch-tis); }
.lc-path--tis-gspo   { color: color-mix(in srgb, var(--ch-tis) 55%, var(--ink) 45%); }
.lc-path--tis_r3     { color: color-mix(in srgb, var(--ch-tis) 55%, var(--ch-r3) 45%); }
.lc-path--tis_r3-gspo{ color: #54808f; }
.lc-path--dppo       { color: var(--ch-dppo); }
.lc-path--baseline,
.lc-path--slime      { color: var(--ch-base); }
.lc-path--slime-gspo { color: color-mix(in srgb, var(--ch-base) 55%, var(--ink) 45%); }

.line-chart path.lc-path { stroke: currentColor; }
.line-chart path.lc-path--satr    { stroke-width: 4.2; }
.line-chart path.lc-path--satr-r3,
.line-chart path.lc-path--satr-r3-deep { stroke-width: 4.4; }
.line-chart path.lc-path--baseline,
.line-chart path.lc-path--slime   { stroke-width: 3.2; }

/* ---- raw / smoothed layers ------------------------------------------------
   Both paths are always attached; visibility is flipped by the toggle button
   at the top-right of each figure. `.lc-raw` (small circles behind the line)
   is only shown when smoothing is ON. */
.line-chart .lc-raw-layer      { pointer-events: none; }
.line-chart .lc-raw            { opacity: .28; }
.line-chart .lc-raw .lc-rawdot { fill: currentColor; stroke: none; }
@media (prefers-color-scheme: dark) {
  .line-chart .lc-raw { opacity: .34; }
}

/* ---- top-right smoothing toggle ------------------------------------------ */
.lc-smooth-toggle {
  position: absolute;
  top: 10px;
  right: 12px;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line, rgba(0, 0, 0, .18));
  background: var(--surface, rgba(255, 255, 255, .92));
  color: var(--fg, #1f2933);
  font: 500 12px/1.15 system-ui, -apple-system, "Segoe UI", sans-serif;
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(0, 0, 0, .08);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  transition: background .15s ease, border-color .15s ease, box-shadow .15s ease;
}
.lc-smooth-toggle:hover  { border-color: rgba(0, 0, 0, .32); box-shadow: 0 2px 6px rgba(0, 0, 0, .12); }
.lc-smooth-toggle:focus-visible { outline: 2px solid #1c5cab; outline-offset: 2px; }
.lc-smooth-toggle__dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: #b7bec6;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .12);
}
.lc-smooth-toggle__dot.is-on {
  background: #1c5cab;
  box-shadow: inset 0 0 0 1px rgba(28, 92, 171, .55), 0 0 0 3px rgba(28, 92, 171, .18);
}
@media (prefers-color-scheme: dark) {
  .lc-smooth-toggle {
    border-color: rgba(255, 255, 255, .18);
    background: rgba(30, 34, 40, .82);
    color: #e6ebf1;
  }
  .lc-smooth-toggle:hover { border-color: rgba(255, 255, 255, .38); }
}
/* The second neutral baseline (GSPO) is dashed so the two grays are never
   distinguished by color alone; it fades in instead of tracing in. */
.line-chart path.lc-path--slime-gspo {
  stroke-width: 3.2;
  stroke-dasharray: 8 6 !important;
  stroke-dashoffset: 0 !important;
  transition: opacity .9s ease .3s;
  opacity: 0;
}
.reveal.is-in     path.lc-path--slime-gspo,
.exp-figure.is-in path.lc-path--slime-gspo { opacity: 1; }

/* ---- hover layer: crosshair + tooltip ---- */
.line-chart .lc-cross   { stroke: var(--faint); stroke-width: 1; stroke-dasharray: 2 4; }
.line-chart .lc-hoverpt { stroke: var(--surface); stroke-width: 1.6; }
.lc-tip {
  position: absolute; z-index: 5; min-width: 172px;
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  backdrop-filter: blur(6px);
  border: 1px solid var(--line); border-radius: 8px;
  padding: 8px 11px;
  font-family: var(--font-sans); font-size: 11.5px; line-height: 1.55;
  color: var(--ink-soft);
  box-shadow: 0 6px 22px rgba(15, 12, 8, .12);
  pointer-events: none;
}
.lc-tip__head { font-weight: 650; color: var(--ink); margin-bottom: 4px; font-variant-numeric: tabular-nums; }
.lc-tip__row  { display: flex; align-items: center; gap: 7px; }
.lc-tip__row i    { width: 11px; height: 3px; border-radius: 2px; flex: none; }
.lc-tip__row span { flex: 1; padding-right: 10px; white-space: nowrap; }
.lc-tip__row b    { font-variant-numeric: tabular-nums; font-weight: 600; }

/* ---- legend chips (click to toggle a series) ---- */
.line-chart__legend {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px;
  margin: 2px 0 -25px;
}.lc-chip {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-sans); font-size: 12px; font-weight: 550;
  color: var(--ink-soft);
  background: var(--surface); border: 1px solid var(--line); border-radius: 999px;
  padding: 4px 12px; cursor: pointer;
  transition: opacity .15s ease, border-color .15s ease;
}
.lc-chip i { width: 16px; height: 3.5px; border-radius: 2px; background: currentColor; display: block; flex: none; }
.lc-chip span { color: var(--ink-soft); }
.lc-chip:hover { border-color: color-mix(in srgb, var(--muted) 45%, var(--line)); }
.lc-chip.is-off { opacity: .42; }
.lc-chip.is-off i { background: var(--faint); }
.line-chart__hint { font-family: var(--font-sans); font-size: 11px; color: var(--faint); margin-left: auto; }
@media (max-width: 720px) { .line-chart__hint { display: none; } }

/* End-of-curve label group (name + steady-state value) drawn by script.js.
   Faded in *after* the path finishes tracing so labels don't fly ahead of
   their curves during the scroll-triggered animation. */
.line-chart .lc-endgroup { opacity: 0; transition: opacity .5s ease 1.5s; }
.exp-figure.is-in .line-chart .lc-endgroup,
.reveal.is-in    .line-chart .lc-endgroup { opacity: 1; }
.line-chart .lc-leader {
  stroke-width: 1 !important;
  stroke-dasharray: 1 4 !important;
  stroke-linecap: round;
  opacity: 0.45;
  fill: none;
  stroke-dashoffset: 0 !important;
  transition: none !important;
}
.line-chart .lc-endpt    { stroke: var(--surface); stroke-width: 2; }
.line-chart .lc-endlabel {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 650;
  letter-spacing: 0.2px;
}
.line-chart .lc-endval   {
  font-family: var(--font-sans);
  font-size: 12.5px;
  font-weight: 500;
  fill: color-mix(in srgb, var(--muted) 80%, var(--line));
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.1px;
}

.line-chart .lc-collapse-marker {
  fill: var(--sienna-ink);
  opacity: 0; transition: opacity .4s ease 1.4s;
}
.exp-figure.is-in .line-chart .lc-collapse-marker,
.reveal.is-in    .line-chart .lc-collapse-marker { opacity: 1; }

.line-chart__ceiling-note {
  /* Sits directly beneath the top-right `.lc-smooth-toggle` pill.
     Toggle button: top:10px + padding 4+4 + ~15px line ≈ 34px tall,
     so we start this note at 44px to leave an 8-10px gap. */
  position: absolute; top: 44px; right: 12px;
  z-index: 2;
  max-width: min(320px, calc(100% - 24px));
  font-family: var(--font-sans); font-size: 11px;
  color: var(--sienna-ink);
  background: color-mix(in srgb, var(--sienna) 12%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--sienna) 30%, var(--line));
  padding: 2px 8px; border-radius: 4px;
  opacity: 0; transition: opacity .5s ease 1.2s;
}
/* --above: promote the note to a standalone banner sitting directly
   between the figure header and the chart body (no absolute positioning). */
.line-chart__ceiling-note--above {
  position: static;
  display: inline-block;
  max-width: 100%;
  margin: 6px 0 10px;
  font-size: 12px;
  padding: 3px 10px;
}
.exp-figure.is-in .line-chart__ceiling-note,
.reveal.is-in    .line-chart__ceiling-note { opacity: 1; }

@media (prefers-reduced-motion: reduce) {
  .bar { transform: none; transition: none; }
  .bar__val { opacity: 1; transition: none; }
  .lc-path { stroke-dashoffset: 0 !important; transition: none; }
  .lc-collapse-marker { opacity: 1; transition: none; }
  .line-chart__ceiling-note { opacity: 1; transition: none; }
}

@media (max-width: 720px) {
  .bar-chart { grid-template-columns: 34px 1fr; }
  .bar-chart__labels { font-size: 10px; }
  .bar-chart--summary .bar-chart__label { font-size: 9px; }
  .exp-figure { padding: 16px 14px 14px; }
}

/* --------  LIGHTBOX (click-to-zoom for every content <img>)  -------- */
.figure img,
.subfigure img,
.subfigure--inline img,
.hero__figure img,
.aside--figure img,
figure img,
.figure--svg > svg,
.line-chart img {
  cursor: zoom-in;
}
.lightbox {
  position: fixed; inset: 0; z-index: 9999;
  display: none;
  background: rgba(20, 20, 24, 0.86);
  align-items: center; justify-content: center;
  padding: 32px;
  cursor: zoom-out;
  opacity: 0;
  transition: opacity .18s ease;
}
.lightbox.is-open { display: flex; opacity: 1; }
.lightbox__img {
  max-width: 96vw; max-height: 92vh;
  object-fit: contain;
  background: var(--surface, #faf5ec);
  border-radius: 6px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
}
.lightbox__caption {
  position: absolute; left: 0; right: 0; bottom: 20px;
  text-align: center; color: #eee9dc;
  font-family: var(--font-sans, system-ui);
  font-size: 13px; opacity: .85; padding: 0 40px;
  pointer-events: none;
}
.lightbox__close {
  position: absolute; top: 16px; right: 20px;
  width: 40px; height: 40px; border-radius: 999px;
  border: none; background: rgba(255,255,255,0.14);
  color: #eee9dc; font-size: 22px; line-height: 1;
  cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background .16s ease, transform .16s ease;
}
.lightbox__close:hover { background: rgba(255,255,255,0.24); transform: scale(1.06); }

@media (prefers-reduced-motion: reduce) {
  .lightbox { transition: none; }
}
.lightbox__svgwrap {
  display: none;
  max-width: 96vw; max-height: 92vh;
  background: var(--surface, #faf5ec);
  border-radius: 6px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
  padding: 18px 22px;
  overflow: auto;
}
.lightbox__svgwrap svg { width: min(1400px, 92vw); height: auto; display: block; }

/* ================================================================
   8. INLINED STATIC SVG FIGURES (theme-aware)
   ---------------------------------------------------------------- */
/* direct child only — figcaptions contain MathJax's own inline <svg>s */
.figure--svg > svg { width: 100%; height: auto; display: block; }

/* ================================================================
   9. PIPELINE DIAGRAMS (inline SVG, §1)
   ---------------------------------------------------------------- */
.pipe { width: 100%; height: auto; display: block; }
.pipe text { font-family: var(--font-sans); }
.pipe .pp-lane-roll   { fill: color-mix(in srgb, var(--sienna) 6%, var(--surface)); stroke: color-mix(in srgb, var(--sienna) 22%, var(--line)); }
.pipe .pp-lane-train  { fill: color-mix(in srgb, var(--accent) 5%, var(--surface)); stroke: color-mix(in srgb, var(--accent) 20%, var(--line)); }
.pipe .pp-lane-title  { font-size: 14.5px; font-weight: 650; fill: var(--ink); }
.pipe .pp-lane-title--roll  { fill: var(--sienna-ink); }
.pipe .pp-lane-title--train { fill: var(--accent-ink); }
.pipe .pp-lane-sub    { font-size: 11px; font-weight: 500; fill: var(--muted); }
.pipe .pp-blk         { fill: color-mix(in srgb, var(--sienna) 15%, var(--surface)); stroke: color-mix(in srgb, var(--sienna) 42%, var(--line)); }
.pipe .pp-blk--train  { fill: color-mix(in srgb, var(--accent) 13%, var(--surface)); stroke: color-mix(in srgb, var(--accent) 40%, var(--line)); }
.pipe .pp-blk--swap   { fill: color-mix(in srgb, var(--sienna) 26%, var(--surface)); }
.pipe .pp-blk-label   { font-size: 13px; font-weight: 600; fill: var(--ink); }
.pipe .pp-blk-sub     { font-size: 10.5px; font-weight: 500; fill: var(--ink-soft); }
.pipe .pp-chip        { fill: var(--surface); stroke: var(--line); stroke-width: 1.1; }
.pipe .pp-chip--train { fill: color-mix(in srgb, var(--accent) 14%, var(--surface)); stroke: color-mix(in srgb, var(--accent) 45%, var(--line)); }
.pipe .pp-chip--roll  { fill: color-mix(in srgb, var(--sienna) 14%, var(--surface)); stroke: color-mix(in srgb, var(--sienna) 45%, var(--line)); }
.pipe .pp-chip-label  { font-size: 12.5px; font-weight: 650; fill: var(--ink); font-style: italic; }
.pipe .pp-queue       { fill: color-mix(in srgb, var(--graphite) 9%, var(--surface)); stroke: color-mix(in srgb, var(--graphite) 32%, var(--line)); }
.pipe .pp-slot        { fill: color-mix(in srgb, var(--accent) 16%, var(--surface)); stroke: color-mix(in srgb, var(--accent) 30%, var(--line)); }
.pipe .pp-slot--empty { fill: var(--surface); stroke: var(--line); stroke-dasharray: 3 3; }
.pipe .pp-note        { font-size: 11.5px; font-weight: 550; fill: var(--sienna-ink); }
.pipe .pp-note-box    { fill: color-mix(in srgb, var(--sienna) 8%, var(--surface)); stroke: color-mix(in srgb, var(--sienna) 30%, var(--line)); }
.pipe .pp-leg         { font-size: 11.5px; font-weight: 500; fill: var(--ink-soft); }
.pipe .pp-time        { stroke: var(--faint); stroke-width: 1.2; }
.pipe .pp-time-lbl    { font-size: 11px; font-weight: 500; fill: var(--faint); letter-spacing: .04em; }

.pipe .pp-grid     { stroke: color-mix(in srgb, var(--muted) 22%, var(--line-soft)); stroke-width: 1; stroke-dasharray: 2 7; }
.pipe .pp-idle     { fill: color-mix(in srgb, var(--muted) 7%, transparent); stroke: color-mix(in srgb, var(--muted) 28%, var(--line)); stroke-width: .8; stroke-dasharray: 3 3; }
.pipe .pp-idle-lbl { font-size: 10px; font-weight: 500; fill: var(--faint); }
.pipe .pp-stepc    { fill: var(--graphite); }
.pipe .pp-step     { font-size: 11px; font-weight: 700; fill: var(--surface); }
.pipe .pp-blk--hl  { stroke: var(--sienna); stroke-width: 2.2; }
.pipe .pp-brace    { fill: none; stroke: var(--sienna-ink); stroke-width: 1.3; }
.pipe .pp-brace-lbl{
  font-size: 11.5px; font-weight: 650; fill: var(--sienna-ink);
  paint-order: stroke; stroke: var(--bg); stroke-width: 3.5px; stroke-linejoin: round;
}
.pipe .pp-seg-a    { fill: color-mix(in srgb, var(--sienna) 11%, var(--surface)); stroke: color-mix(in srgb, var(--sienna) 42%, var(--line)); }
.pipe .pp-seg-b    { fill: color-mix(in srgb, var(--sienna) 28%, var(--surface)); stroke: color-mix(in srgb, var(--sienna) 42%, var(--line)); }
.pipe .pp-seg-lbl  { font-size: 13px; font-weight: 650; font-style: italic; fill: var(--ink); }
.pipe .pp-swapdot  { fill: var(--accent); stroke: var(--surface); stroke-width: 1.6; }
.pipe .pp-qcard-e  { fill: var(--surface); stroke: var(--line); stroke-dasharray: 3 3; }

.pipe .ar   { fill: none; stroke-width: 2; }
.pipe .ar-w { stroke: var(--accent); }       /* update_weights()   */
.pipe .ar-t { stroke: var(--c-good); }       /* optimizer steps    */
.pipe .ar-d { stroke: var(--sienna); }       /* rollout data flow  */
.pipe .mk-w { fill: var(--accent); }
.pipe .mk-t { fill: var(--c-good); }
.pipe .mk-d { fill: var(--sienna); }
.pipe .ar--flow { stroke-dasharray: 5 6; animation: pipeflow 1.15s linear infinite; }
@keyframes pipeflow { to { stroke-dashoffset: -11; } }
@media (prefers-reduced-motion: reduce) { .pipe .ar--flow { animation: none; } }

/* ================================================================
   10. CLIP-GEOMETRY EXPLORER (§5.c / §5.d interactive widget)
   ---------------------------------------------------------------- */
.subfigure--widget { margin: 16px auto 8px; max-width: 680px; }
.subfigure--widget figcaption {
  margin: 10px auto 0; text-align: left;
  font-size: 12.5px; line-height: 1.55; color: var(--muted);
  font-family: var(--font-sans);
}
.subfigure--widget figcaption b { color: var(--ink-soft); font-weight: 600; }

.ce { font-family: var(--font-sans); }
.ce__bar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px 20px;
  margin: 0 0 10px;
}
.ce__signs { display: inline-flex; align-items: center; gap: 6px; }
.ce__sign {
  font-family: var(--font-sans); font-size: 12px; font-weight: 650;
  padding: 4px 13px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface);
  color: var(--muted); cursor: pointer;
  transition: color .15s, border-color .15s, background .15s;
}
.ce__sign.is-on {
  color: var(--accent-ink);
  border-color: color-mix(in srgb, var(--accent) 48%, var(--line));
  background: var(--accent-wash);
}
.ce__note { font-size: 11px; color: var(--faint); margin-left: 6px; max-width: 320px; line-height: 1.4; }
.ce__sliders { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.ce__slider { display: inline-flex; align-items: center; gap: 8px; font-size: 12px; font-weight: 550; color: var(--ink-soft); }
.ce__slider input[type="range"] { width: 110px; accent-color: var(--accent); }
.ce__slider-val { font-variant-numeric: tabular-nums; color: var(--ink); min-width: 4ch; font-weight: 600; }

.ce__svg {
  width: 100%; height: auto; display: block;
  background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--radius-sm);
  touch-action: pan-y;
}
.ce-grid  { stroke: var(--line-soft); stroke-width: .8; }
.ce-frame { fill: none; stroke: var(--line); stroke-width: 1; }
.ce-tick  { font-family: var(--font-sans); font-size: 12px; fill: var(--muted); }
.ce-axlbl { font-family: var(--font-sans); font-size: 13px; font-weight: 500; fill: var(--ink-soft); }
.ce-diag  { stroke: var(--faint); stroke-width: 1.2; stroke-dasharray: 4 5; }
.ce-lbl   { font-family: var(--font-sans); font-size: 11px; fill: var(--faint); }
.ce-blbl  {
  font-family: var(--font-sans); font-size: 11.5px; font-weight: 650; fill: var(--ink-soft);
  paint-order: stroke; stroke: var(--surface); stroke-width: 3.5px; stroke-linejoin: round;
}
.ce-bound { fill: none; stroke: var(--ink-soft); stroke-width: 1.7; }
.ce-ref   { fill: none; stroke: var(--faint); stroke-width: 1.4; stroke-dasharray: 2 5; }
.ce-dot   { fill: var(--ink); stroke: var(--surface); stroke-width: 1.6; pointer-events: none; }

.ce-region { stroke: none; }
.ce-region--keep  { fill: color-mix(in srgb, var(--accent) 13%, transparent); }
.ce-region--pull  { fill: color-mix(in srgb, var(--c-good) 11%, transparent); }
.ce-region--trunc { fill: color-mix(in srgb, var(--c-warn) 13%, transparent); }
.ce-region--damp  { fill: color-mix(in srgb, var(--accent) 7%, transparent); }
.ce-hatch-bg   { fill: color-mix(in srgb, var(--muted) 7%, transparent); }
.ce-hatch-line { stroke: color-mix(in srgb, var(--muted) 38%, transparent); stroke-width: 1; }

.ce__read {
  font-family: var(--font-sans); font-size: 12.5px; line-height: 1.55;
  color: var(--ink-soft); margin: 9px 2px 0; min-height: 21px;
}
.ce__read em { color: var(--faint); }
.ce__read-nums { font-variant-numeric: tabular-nums; color: var(--ink); font-weight: 550; }
.ce__read-verdict { font-weight: 650; }
.ce__read-verdict--keep  { color: var(--accent-ink); }
.ce__read-verdict--pull  { color: var(--c-good); }
.ce__read-verdict--dead  { color: var(--c-warn); }
.ce__read-verdict--trunc { color: var(--c-warn); }
.ce__read-verdict--damp  { color: var(--accent-ink); }

.ce__legend {
  display: flex; flex-wrap: wrap; gap: 6px 16px; margin-top: 7px;
  font-family: var(--font-sans); font-size: 11.5px; font-weight: 500; color: var(--muted);
}
.ce__lg { display: inline-flex; align-items: center; gap: 6px; }
.ce__lg i { width: 14px; height: 10px; border-radius: 2px; border: 1px solid var(--line); flex: none; }
.ce__lg--keep i  { background: color-mix(in srgb, var(--accent) 13%, var(--surface)); }
.ce__lg--pull i  { background: color-mix(in srgb, var(--c-good) 11%, var(--surface)); }
.ce__lg--dead i  {
  background: repeating-linear-gradient(45deg,
    transparent 0 3px, color-mix(in srgb, var(--muted) 38%, transparent) 3px 4.5px);
}
.ce__lg--trunc i { background: color-mix(in srgb, var(--c-warn) 13%, var(--surface)); }
.ce__lg--damp i  { background: color-mix(in srgb, var(--accent) 7%, var(--surface)); }