:root {
  --ink: #333333;
  --muted: #666666;
  --accent: #1f6fc4;
  --accent-dark: #185a9e;
  --accent-mid: #3b8fdc;
  --accent-bright: #5eb1f4;
  --accent-soft: #ebf4fd;
  --accent-line: #c7e0f7;
  --line: #e5e5e5;
  --line-soft: #eeeeee;
  --band: #f7f7f7;
  --font: 'Google Sans Flex', 'Helvetica Neue', Helvetica, Arial, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body { margin: 0; background: #fff; color: var(--ink); font-family: var(--font); font-size: 16px; line-height: 1.7; font-optical-sizing: auto; -webkit-font-smoothing: antialiased; }
a { color: var(--accent-dark); text-decoration: none; }
a:hover { color: var(--accent); }
button { font: inherit; cursor: pointer; }
button, a, video { -webkit-tap-highlight-color: transparent; }
button, a { touch-action: manipulation; }
button:focus-visible, a:focus-visible, [tabindex]:focus-visible, video:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
img { display: block; max-width: 100%; height: auto; }
figure, p, h1, h2, h3, h4 { margin: 0; }
[hidden] { display: none !important; }
sub, sup { line-height: 0; }
code { font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace; font-size: .92em; padding: 1px 5px; border-radius: 5px; background: #f1f1f1; color: #2f2f2f; }
.container { width: min(1020px, calc(100% - 48px)); margin-inline: auto; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; }
.skip-link { position: fixed; top: -70px; left: 12px; z-index: 60; background: #fff; padding: 10px; }
.skip-link:focus { top: 12px; }

/* Navigation */
.site-nav { height: 60px; position: sticky; top: 0; z-index: 20; background: #ffffffed; backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.nav-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: baseline; color: var(--ink); font-size: 20px; font-weight: 750; letter-spacing: -.3px; }
.brand:hover { color: var(--ink); }
.brand-dot { color: var(--accent-bright); }
.nav-links { display: flex; align-items: center; gap: 25px; }
.nav-links a { color: var(--muted); font-size: 13px; font-weight: 500; }
.nav-links a:hover { color: var(--accent); }

/* Header */
.paper-header { padding: 23px 0 22px; text-align: center; }
.hero-wordmark { color: var(--ink); font-size: clamp(44px, 10vw, 68px); font-weight: 800; line-height: 1.05; letter-spacing: -.035em; white-space: nowrap; }
.hero-wordmark .brand-dot { color: var(--accent-bright); }
h1 { font-size: clamp(26px, 2.8vw, 34px); font-weight: 750; line-height: 1.2; letter-spacing: -.6px; margin: 13px auto 0; text-wrap: balance; }
.hero-meta { margin-top: 20px; }
.authors { font-size: 15.5px; font-weight: 500; line-height: 1.9; }
.author { white-space: nowrap; }
.authors a { color: var(--accent-dark); }
.authors a:hover { color: var(--accent); }
.authors sup { margin-left: 1px; font-size: .7em; color: var(--muted); }
.affiliations, .author-notes { display: flex; flex-wrap: wrap; justify-content: center; gap: 2px 18px; }
.affiliations { margin-top: 8px; font-size: 14.5px; color: var(--ink); }
.author-notes { margin-top: 4px; font-size: 13px; color: var(--muted); }
.affiliations span, .author-notes span { white-space: nowrap; }
.affiliations sup, .author-notes sup { margin-right: 2px; font-size: .7em; color: var(--muted); }
.venue { display: inline-block; margin-top: 14px; padding: 4px 16px; border: 1px solid var(--accent-line); border-radius: 99px; background: var(--accent-soft); color: var(--accent-dark); font-size: 15.5px; font-weight: 650; letter-spacing: .1px; }

/* Paper resource buttons */
.hero-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 20px; }
.link-button { display: inline-flex; align-items: center; gap: 8px; height: 40px; padding: 0 18px 0 15px; border: 0; border-radius: 99px; background: #262626; color: #fff; font-size: 14.5px; font-weight: 600; line-height: 1; white-space: nowrap; transition: background-color .15s ease; }
.link-button:hover { background: #404040; color: #fff; }
.link-button .icon { display: block; flex-shrink: 0; width: 17px; height: 17px; }

/* TL;DR + overview video */
.tldr-section { padding-top: 13px; padding-bottom: 44px; }
.tldr-box { display: flex; align-items: flex-start; gap: 18px; padding: 18px 22px; border-radius: 10px; background: var(--accent-soft); }
.tldr-tag { flex-shrink: 0; padding: 3px 10px; margin-top: 3px; border-radius: 99px; background: var(--accent); color: #fff; font-size: 11px; font-weight: 700; letter-spacing: .2px; line-height: 1.8; }
.tldr-box p { font-size: 15px; line-height: 1.8; }

/* Figures */
.paper-figure { margin-top: 28px; padding: 20px 22px 0; border: 1px solid var(--line); border-radius: 12px; background: #fff; box-shadow: 0 5px 22px #0000000d; }
.paper-figure img { width: 100%; }
.paper-figure figcaption { margin-top: 13px; padding: 14px 0 17px; border-top: 1px solid var(--line-soft); font-size: 12px; color: var(--muted); text-align: center; }
.paper-figure figcaption strong { color: var(--ink); font-weight: 550; }
.paper-figure a { display: block; }
video { display: block; width: 100%; height: auto; background: #0d1114; }
.video-figure { padding: 0; overflow: hidden; }
.video-figure figcaption { margin-top: 0; padding: 12px 18px 14px; }

/* Sections */
.section-band { background: var(--band); border-block: 1px solid var(--line-soft); }
.page-section { padding-block: 65px; }
.section-heading { margin-bottom: 30px; }
h2 { font-size: 30px; font-weight: 700; line-height: 1.3; letter-spacing: -.5px; }
.section-heading > p { margin-top: 12px; font-size: 15px; color: var(--muted); }
h3 { font-size: 18px; font-weight: 650; line-height: 1.4; }
.sub-block { margin-top: 56px; }
.sub-heading { margin: 0 0 18px; font-size: 18px; line-height: 1.4; font-weight: 650; color: var(--ink); }
.sub-intro { margin: -8px 0 20px; font-size: 14px; line-height: 1.8; color: var(--muted); }

/* Figure spotlight (test-time scaling panels) */
.spot-figure { margin-top: 0; padding: 20px 22px; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.spot-canvas { position: relative; width: 100%; overflow: hidden; }
.spot-canvas > img { width: 100%; }
.spot-hole { position: absolute; left: 0; top: 0; width: 100%; height: 100%; border-radius: 10px; pointer-events: none; opacity: 0; box-shadow: 0 0 0 2400px #ffffffa6; transition: left .22s ease, top .22s ease, width .22s ease, height .22s ease, opacity .15s ease; }
.spot-figure[data-active] .spot-hole { opacity: 1; }
.spot-region { position: absolute; top: 0; height: 100%; border: 0; padding: 0; background: transparent; }
.spot-region:focus, .spot-callout:focus { outline: none; }
.spot-region:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; border-radius: 8px; }
.spot-callouts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; padding: 0; margin: 18px 0 0; list-style: none; }
.spot-callout { display: flex; flex-direction: column; align-items: flex-start; justify-content: flex-start; width: 100%; min-height: 100%; padding: 12px 13px; border: 0; border-radius: 8px; background: transparent; color: var(--ink); text-align: left; transition: background-color .15s ease; }
.spot-callout.is-active, .spot-callout:focus-visible { background: var(--accent-soft); }
.spot-callout strong { display: block; font-size: 14px; line-height: 1.45; font-weight: 650; }
.callout-description { display: block; margin-top: 6px; font-size: 13px; line-height: 1.7; color: var(--muted); }

/* Qualitative test-time scaling pair */
.qual-pair { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 16px; }
.qual-pair .paper-figure { margin-top: 0; display: flex; flex-direction: column; }
.qual-pair .paper-figure > img { flex: 1; object-fit: contain; }

/* Tabs */
.tab-list { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 16px; padding: 4px; border-radius: 11px; background: #efefef; width: fit-content; max-width: 100%; }
.section-band .tab-list { background: #eaeaea; }
.tab { padding: 5px 13px; border: 0; border-radius: 8px; background: transparent; color: var(--muted); font-size: 13px; font-weight: 550; line-height: 1.5; white-space: nowrap; }
.tab:hover { color: var(--ink); }
.tab[aria-selected="true"] { background: #fff; color: var(--accent-dark); box-shadow: 0 1px 3px #0000001f; }
.tab-panel:focus-visible { outline: none; }

footer { border-top: 1px solid var(--line); padding-block: 24px; background: #f8f8f8; }
.footer-content { display: flex; justify-content: flex-end; align-items: center; gap: 20px; font-size: 12px; color: var(--muted); }
footer a { color: var(--muted); }

@media (max-width: 760px) {
  .container { width: calc(100% - 40px); }
  .nav-links { gap: 15px; }
  .nav-links a { font-size: 12px; }
  .nav-links a:first-child { display: none; }
  .paper-header { padding-top: 30px; }
  h1 { font-size: 32px; }
  .tldr-box { padding: 17px 19px; gap: 14px; }
  .tldr-box p { font-size: 14px; }
  .paper-figure { padding: 16px 16px 0; }
  .video-figure { padding: 0; }
  .page-section { padding-block: 48px; }
  .tldr-section { padding-bottom: 34px; }
  h2 { font-size: 27px; }
  .spot-callouts { grid-template-columns: 1fr; gap: 4px; }
  .qual-pair { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 520px) {
  .container { width: calc(100% - 32px); }
  .site-nav { height: 55px; }
  .brand { font-size: 18px; }
  .nav-links { gap: 12px; }
  .nav-links a { font-size: 11px; }
  .paper-header { padding: 26px 0 23px; }
  h1 { font-size: 27px; line-height: 1.2; letter-spacing: -.4px; margin-top: 13px; }
  .hero-meta { margin-top: 16px; }
  .authors { font-size: 14px; line-height: 1.85; }
  .affiliations { font-size: 13px; gap: 2px 12px; }
  .author-notes { font-size: 12px; gap: 2px 12px; }
  .venue { font-size: 14px; padding: 3px 14px; }
  .hero-links { gap: 8px; margin-top: 16px; }
  .link-button { height: 36px; padding: 0 14px 0 12px; gap: 7px; font-size: 13.5px; }
  .link-button .icon { width: 16px; height: 16px; }
  .tldr-section { padding-top: 9px; }
  .tldr-box { display: block; padding: 15px 17px; }
  .tldr-tag { display: inline-block; margin: 0 0 7px; font-size: 10px; }
  .tldr-box p { font-size: 13px; line-height: 1.75; }
  .paper-figure { margin-top: 21px; padding: 11px 11px 0; border-radius: 9px; }
  .video-figure { padding: 0; }
  .paper-figure figcaption { font-size: 11px; padding-block: 12px; margin-top: 12px; }
  .video-figure figcaption { margin-top: 0; padding-inline: 12px; }
  h2 { font-size: 25px; }
  .section-heading { margin-bottom: 24px; }
  .section-heading > p { font-size: 13px; }
  .spot-figure { padding: 10px; }
  .tab { padding: 5px 10px; font-size: 12px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}