/* =========================================================
   VERITAS — Thinking Machines-style research blog post
   Body: Iowan Old Style / Georgia serif
   UI:   system sans (GT America-equivalent fallback)
   Logo: Chakra Petch
   ========================================================= */

:root {
  /* Gruvbox-derived warm palette, mirroring thinkingmachines.ai */
  --bg:        #ffffff;
  --bg-code:   #f3f3f2;
  --bg-soft:   #faf9f7;
  --fg:        #282828;
  --fg1:       #3c3836;
  --fg2:       #504945;
  --fg3:       #6b6866;
  --fg4:       #676767;
  --fg5:       #969696;
  --rule:      #e6e3dd;

  --red:       #ad2111;
  --blue:      #0e9ee4;
  --orange:    #af3a03;

  --font-serif: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-sans:  'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-mono:  'SF Mono', 'Menlo', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
  --font-logo:  'Chakra Petch', var(--font-sans);

  --site-header-height: 56px;
  --content-max: 720px;
  --content-wide: 1040px;
  --gutter: clamp(18px, 4vw, 32px);
  --side-menu-w: 260px;
}

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

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--site-header-height) + 12px); }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; }

/* =========================================================
   HEADER (non-sticky top bar)
   ========================================================= */
#header {
  border-bottom: 1px solid var(--rule);
  background: var(--bg);
}
.topbar {
  height: var(--site-header-height);
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.navbar-logo { text-decoration: none; }
.logo-mark {
  font-family: var(--font-logo);
  font-weight: 500;
  font-size: 16px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg4);
  transition: opacity 0.3s ease;
}
.navbar-logo:hover .logo-mark { opacity: 0.75; }

/* =========================================================
   SIDE MENU
   ========================================================= */
.side-menu {
  display: none;
}

@media (min-width: 1100px) {
  .side-menu {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--side-menu-w);
    background: transparent;
    overflow-y: auto;
    z-index: 5;
  }
  .side-menu-inner {
    padding: 28px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 100%;
  }

  /* Hide the top header on wide screens — the side menu carries identity */
  #header { display: none; }

  /* Push everything right of the sidebar */
  .article-wrap { padding-left: calc(var(--side-menu-w) + var(--gutter)); }
  .site-footer  { padding-left: calc(var(--side-menu-w) + var(--gutter)); }

  /* Re-center the gallery's full-bleed break-out relative to the new content area */
  .video-gallery-container {
    width: calc(100vw - var(--side-menu-w));
    margin-left: calc(50% - (var(--side-menu-w) / 2));
    transform: translateX(-50%);
  }
}

.side-toc {
  font-family: var(--font-sans);
}
.side-toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.side-toc li {
  margin: 0 0 0.7rem 0;
  position: relative;
}
.side-toc a {
  display: block;
  position: relative;
  padding: 2px 0 2px 18px;
  font-size: 13.5px;
  line-height: 1.4;
  color: var(--fg4);
  text-decoration: none;
  transition: color 0.2s ease;
}
.side-toc a::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 0.65em;
  width: 5px;
  height: 5px;
  background: var(--fg);
  border-radius: 50%;
  opacity: 0;
  transform: translateY(-50%);
  transition: opacity 0.18s ease;
}
.side-toc a:hover {
  color: var(--fg1);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--fg1) 20%, transparent);
  text-underline-offset: 2px;
}
.side-toc a.is-active {
  color: var(--fg);
}
.side-toc a.is-active::before { opacity: 1; }

.side-meta {
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
  font-family: var(--font-sans);
}
.side-meta-label {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg5);
  margin-bottom: 8px;
}
.side-meta-body {
  font-size: 13px;
  line-height: 1.55;
  color: var(--fg2);
}
.side-meta-body a {
  color: var(--fg2);
  text-decoration: none;
  transition: color 0.2s ease;
}
.side-meta-body a:hover { color: var(--fg); }
.side-meta-muted {
  color: var(--fg4);
  font-size: 12px;
  display: inline-block;
  margin-top: 3px;
}

/* =========================================================
   ARTICLE
   ========================================================= */
.article-wrap {
  padding: clamp(40px, 6vw, 72px) var(--gutter) clamp(48px, 7vw, 96px);
}
.article {
  max-width: var(--content-max);
  margin: 0 auto;
}

/* =========================================================
   PAPER HEADER (academic project-page style)
   ========================================================= */
.paper-header {
  text-align: center;
  margin-bottom: clamp(40px, 6vw, 64px);
  padding-bottom: clamp(28px, 4vw, 40px);
  border-bottom: 1px solid var(--rule);
}

.paper-title {
  font-family: var(--font-serif);
  font-weight: 550;
  font-size: clamp(22px, 2.8vw, 34px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--fg);
  max-width: none;
  margin: 0 auto 32px;
}
.paper-title .title-line {
  display: block;
}
@media (min-width: 820px) {
  .paper-title .title-line {
    white-space: nowrap;
  }
}

.paper-authors {
  font-family: var(--font-serif);
  font-size: clamp(17px, 1.7vw, 19px);
  line-height: 1.55;
  margin: 0 0 6px;
  color: var(--fg);
}
.paper-authors .author { display: inline-block; }
.paper-authors a {
  color: var(--fg);
  text-decoration: none;
  transition: color 0.25s ease;
}
.paper-authors a:hover {
  color: var(--blue);
}
.paper-authors sup {
  font-size: 0.62em;
  color: var(--fg4);
  margin-left: 1px;
  vertical-align: super;
  line-height: 0;
}
.author-sep {
  margin: 0 12px;
  color: var(--fg5);
}

.paper-affiliations {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  color: var(--fg3);
  margin: 0 0 10px;
}
.paper-affiliations sup {
  font-size: 0.72em;
  margin-right: 1px;
  vertical-align: super;
  line-height: 0;
}
.paper-venue {
  font-family: var(--font-sans);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg2);
  margin: 0 0 28px;
}

.paper-links-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 22px;
  font-family: var(--font-mono);
  font-size: 17px;
  margin-bottom: 24px;
}
.paper-links-row a {
  color: var(--fg);
  text-decoration: none;
  transition: color 0.2s ease;
}
.paper-links-row a:hover {
  color: var(--blue);
}

/* =========================================================
   CONTENT BODY
   ========================================================= */
.content > * + * { margin-top: 1.1em; }
.content h2 + p,
.content h3 + p,
.content h2 + .mechanism-steps { margin-top: 0.7em; }

.content p {
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.65;
  color: var(--fg);
}

.content em { font-style: italic; color: var(--fg1); }
.content strong { font-weight: 600; color: var(--fg); }

.content a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--fg4) 30%, transparent);
  text-underline-offset: 2px;
  transition: color 0.25s ease, text-decoration-color 0.25s ease;
}
.content a:hover { color: var(--fg2); text-decoration-color: var(--fg2); }

.content h2 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(24px, 2.6vw, 30px);
  line-height: 1.22;
  letter-spacing: -0.005em;
  color: var(--fg);
  margin-top: 2.8em;
  padding-top: 1.4em;
  margin-bottom: 0.6em;
  text-wrap: balance;
  display: flex;
  align-items: baseline;
  gap: 14px;
  position: relative;
}
.content h2::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 64px;
  height: 1px;
  background: var(--fg);
}
.content h2 .h2-num {
  font-family: var(--font-serif);
  font-weight: 500;
  color: var(--fg3);
  font-size: 0.78em;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.content h3 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 19px;
  line-height: 1.3;
  color: var(--fg1);
  margin-top: 1.8em;
  margin-bottom: 0.4em;
}

/* =========================================================
   HERO FIGURE
   ========================================================= */
.hero-figure {
  margin: 0 0 4.5em;
}
.hero-figure img,
.hero-figure video {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 4px;
  background: var(--bg-soft);
}

/* Let the hero figure break out beyond the prose column on wider viewports */
@media (min-width: 820px) {
  .hero-figure {
    width: min(calc(100vw - 2 * var(--gutter)), 1080px);
    margin-left: 50%;
    transform: translateX(-50%);
  }
  .hero-figure figcaption {
    max-width: 720px;
    margin-left: auto;
    margin-right: auto;
  }
}
@media (min-width: 1100px) {
  .hero-figure {
    width: min(calc(100vw - var(--side-menu-w) - 2 * var(--gutter)), 1080px);
  }
}

/* Smaller variant — used for charts / barplots that shouldn't span full width */
.hero-figure.is-small {
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
@media (min-width: 820px) {
  .hero-figure.is-small {
    width: min(calc(100vw - 2 * var(--gutter)), 600px);
    margin-left: 50%;
    margin-right: 0;
    /* inherits transform: translateX(-50%) from .hero-figure */
  }
}
@media (min-width: 1100px) {
  .hero-figure.is-small {
    width: min(calc(100vw - var(--side-menu-w) - 2 * var(--gutter)), 600px);
  }
}
.hero-figure figcaption,
.content figcaption {
  margin-top: 12px;
  font-family: var(--font-sans);
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--fg3);
}
.figure-label {
  font-family: var(--font-sans);
  font-weight: 500;
  color: var(--fg1);
  margin-right: 4px;
}

/* =========================================================
   MECHANISM STEPS
   ========================================================= */
.mechanism-steps {
  list-style: none;
  padding: 0;
  margin: 1.4em 0 0;
  border-top: 1px solid var(--rule);
}
.mechanism-steps li {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  align-items: baseline;
}
.step-num {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 16px;
  color: var(--fg4);
}
.step-body { font-size: 19px; line-height: 1.6; }
.step-body strong { font-weight: 600; color: var(--fg); margin-right: 2px; }

/* =========================================================
   VIDEO GALLERY
   ========================================================= */
.video-gallery-section {
  margin: 1.8em 0 4.5em;
}
.video-gallery-container {
  /* Break out beyond the narrow prose column so two videos fit side-by-side */
  width: 100vw;
  position: relative;
  margin-left: 50%;
  transform: translateX(-50%);
}
.video-gallery {
  display: grid;
  grid-template-columns: repeat(2, auto);
  justify-content: center;
  column-gap: 24px;
  row-gap: 28px;
  padding: 0 var(--gutter);
}

.result-card {
  margin: 0;
  display: inline-flex;
  flex-direction: column;
  align-items: flex-start;
}
.result-card .video-frame {
  position: relative;
  display: block;
  width: min(760px, calc(60vh * 16 / 9), 100%);
  aspect-ratio: 16 / 9;
  margin-left: auto;
  margin-right: auto;
  line-height: 0;
}
.result-card .video-frame .gallery-video {
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
}
.result-card .gallery-video {
  display: block;
  height: 260px;
  width: auto;
  background: transparent;
  border-radius: 4px;
}
.video-instruction {
  position: absolute;
  left: 50%;
  bottom: 12px;
  transform: translateX(-50%);
  max-width: calc(100% - 24px);
  padding: 6px 12px;
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.3;
  color: #fff;
  text-align: center;
  white-space: nowrap;
  background: rgba(0, 0, 0, 0.55);
  border-radius: 4px;
  pointer-events: none;
}
@media (max-width: 640px) {
  .video-instruction {
    font-size: 12px;
    padding: 5px 10px;
    white-space: normal;
  }
}
.result-card figcaption {
  margin-top: 10px;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--fg3);
  max-width: 480px;
}

.gallery-caption-container {
  max-width: var(--content-max);
  margin: 18px auto 0;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}
/* Scroll-arrow buttons are no longer needed in the default 2x2 grid layout */
.gallery-nav-controls { display: none; }

/* Slider variant — discrete switch, only the active card is rendered */
.video-gallery-section.is-slider .video-gallery-container {
  overflow: hidden;
}
.video-gallery-section.is-slider .video-gallery {
  display: flex;
  grid-template-columns: none;
  flex-wrap: nowrap;
  justify-content: center;
  width: 100%;
  column-gap: 0;
  row-gap: 0;
  padding: 0 var(--gutter);
}
.video-gallery-section.is-slider .result-card {
  display: none;
  flex: 0 0 auto;
  flex-direction: column;
  align-items: center;
  margin: 0;
  padding: 0;
}
.video-gallery-section.is-slider .result-card.is-active {
  display: flex;
}
.video-gallery-section.is-slider .result-card .gallery-video {
  display: block;
  height: auto;
  width: auto;
  max-width: min(760px, 100%);
  max-height: 60vh;
  background: transparent;
  border-radius: 4px;
}
.video-gallery-section.is-slider .result-card figcaption {
  margin-top: 12px;
  text-align: center;
  max-width: 720px;
}

.video-gallery-section.is-slider .gallery-nav-controls {
  display: flex;
  gap: 10px;
  flex-shrink: 0;
}
.video-gallery-section.is-slider .gallery-nav {
  width: 38px;
  height: 38px;
  display: inline-grid;
  place-items: center;
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: 999px;
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--fg2);
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}
.video-gallery-section.is-slider .gallery-nav:hover {
  background: var(--fg);
  color: var(--bg);
  border-color: var(--fg);
}
.video-gallery-section.is-slider .gallery-caption-container {
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 14px;
}
.video-gallery-section.is-slider .figure-caption.gallery-caption {
  text-align: center;
  max-width: 640px;
  margin: 0;
}
.figure-caption.gallery-caption {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 13.5px;
  color: var(--fg3);
  line-height: 1.55;
  text-align: center;
}

@media (max-width: 760px) {
  .video-gallery { grid-template-columns: 1fr; }
  .result-card { width: 100%; align-items: stretch; }
  .result-card .gallery-video {
    width: 100%;
    height: auto;
  }
}

/* =========================================================
   BIBTEX
   ========================================================= */
.bibtex {
  background: var(--bg-code);
  border-radius: 6px;
  padding: 18px 20px;
  margin-top: 1em;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.55;
  color: var(--fg1);
  font-variant-ligatures: none;
}
.bibtex code {
  font-family: inherit;
  white-space: pre;
  display: block;
}

/* =========================================================
   FOOTER
   ========================================================= */
.site-footer {
  border-top: 1px solid var(--rule);
  padding: 28px var(--gutter);
  margin-top: clamp(48px, 7vw, 96px);
}
.site-footer-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--fg4);
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}
.site-footer-inner a {
  color: var(--fg2);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--fg4) 30%, transparent);
  text-underline-offset: 2px;
}
.site-footer-inner a:hover { color: var(--fg); text-decoration-color: var(--fg); }
.footer-sep { color: var(--fg5); }