/* =========================================================
   DeltaDirect — academic project page
   ========================================================= */

:root {
  --bg:        #ffffff;
  --bg-soft:   #f7f8fb;
  --bg-3:      #eef1f7;
  --panel:     #ffffff;
  --border:    #e4e7ef;
  --border-2:  #cdd2de;
  --text:      #1a1d2e;
  --text-2:    #3f455c;
  --muted:     #707690;
  --link:      #4338ca;
  --link-hover:#3730a3;
  --primary:   #4338ca;       /* indigo */
  --primary-2: #3730a3;
  --accent:    #7c3aed;       /* violet — pairs with primary in gradient */
  --warm:      #b45309;
  --danger:    #b91c1c;
  --ok:        #047857;
  --grad:      linear-gradient(120deg, #4338ca 0%, #7c3aed 100%);
  --shadow-1:  0 1px 2px rgba(15, 17, 38, 0.04), 0 4px 14px rgba(15, 17, 38, 0.05);
  --shadow-2:  0 4px 12px rgba(15, 17, 38, 0.06), 0 18px 40px rgba(15, 17, 38, 0.06);
  --radius:    10px;
  --radius-s:  8px;
  /* System sans stack: Helvetica-derived on Mac (SF Pro), Segoe on Windows.
     Modern, classic, not "AI/Vercel-feel" like Inter. */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-serif:'Newsreader', 'Times New Roman', Georgia, serif;
  --font-mono: 'JetBrains Mono', ui-monospace, Menlo, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html {
  scroll-behavior: smooth;
  /* Bumped from default 16px → 17px so all rem-based text reads larger,
     especially small captions / tags / italic emphasis. */
  font-size: 17px;
}
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img { display: block; max-width: 100%; }
a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hover); }
button { font: inherit; cursor: pointer; }

::selection { background: rgba(30, 58, 138, 0.18); color: var(--text); }

/* Global emphasis: system-sans italic at semibold weight + primary color.
   Same font family as the body (SF Pro / Segoe UI), so italic glyphs flow
   naturally instead of jumping out as a foreign serif. */
em {
  font-family: inherit;
  font-style: italic;
  font-weight: 600;
  font-size: 1em;
  letter-spacing: -0.005em;
  color: var(--primary);
}

/* Scroll progress */
.scroll-progress {
  position: fixed; top: 0; left: 0; height: 2px; width: 0%;
  background: var(--primary);
  z-index: 1000;
  transition: width 0.06s linear;
}

/* ===================== NAV ===================== */
.nav {
  position: sticky; top: 0; z-index: 900;
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid var(--border);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--text);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: -0.01em;
  line-height: 1.15;
}
.brand:hover { color: var(--text); }
.brand-mark {
  display: inline-grid; place-items: center;
  width: 30px; height: 30px;
  border-radius: 7px;
  background: var(--grad);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.brand-stack {
  display: inline-flex;
  flex-direction: column;
  gap: 1px;
}
.brand-text { color: var(--text); }
.brand-lab {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}
.nav-links {
  list-style: none; padding: 0; margin: 0;
  display: flex; gap: 6px;
}
.nav-links a {
  display: inline-block;
  padding: 8px 12px;
  font-size: 0.9rem;
  color: var(--text-2);
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover { color: var(--text); background: var(--bg-soft); }
.nav-links a.active { color: var(--primary); font-weight: 600; }

@media (max-width: 800px) {
  .nav-links { gap: 0; overflow-x: auto; max-width: 60%; }
  .nav-links a { padding: 8px 8px; font-size: 0.84rem; }
  .brand-text { display: none; }
}

/* ===================== CONTAINER ===================== */
.container {
  width: min(1120px, 100%);
  margin: 0 auto;
  padding: 0 24px;
}
.container.narrow { width: min(780px, 100%); }

/* ===================== HERO ===================== */
.hero {
  padding: 80px 0 64px;
  text-align: center;
  background:
    radial-gradient(circle at 50% 0%, rgba(30, 58, 138, 0.05), transparent 60%),
    var(--bg);
  border-bottom: 1px solid var(--border);
}
.hero-meta {
  display: inline-flex; align-items: center;
  gap: 14px;
  margin-bottom: 22px;
}
.lab-chip {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 5px 12px 5px 11px;
  background: #fff;
  border: 1px solid var(--border-2);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text);
  letter-spacing: 0.01em;
  transition: border-color 0.18s, color 0.18s;
}
.lab-chip:hover { border-color: var(--primary); color: var(--primary); }
.lab-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 0 2px rgba(30, 58, 138, 0.18);
}
.hero-eyebrow {
  display: inline-block;
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
@media (max-width: 560px) {
  .hero-meta { flex-direction: column; gap: 8px; }
}
.hero-title {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.95rem, 4.2vw, 2.95rem);
  line-height: 1.18;
  letter-spacing: -0.015em;
  color: var(--text);
  margin: 0 0 14px;
  max-width: 920px;
  margin-left: auto;
  margin-right: auto;
}
.title-sub {
  display: inline-block;
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: clamp(1.05rem, 1.8vw, 1.3rem);
  color: var(--text-2);
  letter-spacing: 0;
  margin-top: 8px;
}
.authors {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 4px 16px;
  margin: 28px 0 6px;
  font-size: 0.98rem;
  color: var(--text);
}
.author { white-space: nowrap; }
.author sup { color: var(--primary); font-weight: 600; }
.author-link {
  color: var(--text);
  font-weight: 700;
  border-bottom: 1px solid var(--border-2);
  transition: color 0.18s, border-color 0.18s;
}
.author-link:hover { color: var(--primary); border-color: var(--primary); }
.affil {
  font-size: 0.88rem;
  color: var(--muted);
  margin: 0 0 30px;
}
.affil .sep { margin: 0 6px; opacity: 0.5; }
.affil sup { color: var(--primary); }

.hero-links {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 8px;
}
.link-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 16px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border-2);
  border-radius: 999px;
  transition: all 0.18s;
  box-shadow: 0 1px 0 rgba(15, 17, 38, 0.02);
}
.link-btn:hover {
  color: var(--primary);
  border-color: var(--primary);
  transform: translateY(-1px);
}
.link-btn i { color: var(--primary); }

/* ===================== SECTIONS ===================== */
.section {
  padding: 80px 0;
  border-bottom: 1px solid var(--border);
}
.section-tight { padding: 48px 0 24px; border-bottom: none; }
.section-soft  { background: var(--bg-soft); }
.section:last-of-type { border-bottom: 0; }

.section-title {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.55rem, 2.6vw, 2.05rem);
  letter-spacing: -0.012em;
  color: var(--text);
  margin: 0 0 12px;
  text-align: center;
}
.section-desc {
  max-width: 780px;
  margin: 0 auto 40px;
  text-align: center;
  font-size: 1rem;
  color: var(--text-2);
}
/* em inherits the global rule (serif italic 600 + primary color) */

/* ===================== DEMO ===================== */
.vdemo {
  display: grid;
  grid-template-columns: minmax(300px, 380px) 1fr;
  gap: 40px;
  align-items: start;
  padding: 28px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}
@media (max-width: 820px) {
  .vdemo { grid-template-columns: 1fr; gap: 28px; }
}

/* left stage: synthetic animation + direction picker */
.vdemo-stage { display: flex; flex-direction: column; align-items: center; gap: 16px; }
.vdemo-screen {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  background:
    radial-gradient(circle at center, #ffffff 0%, #f4f5fa 100%);
  border-radius: var(--radius-s);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: inset 0 1px 2px rgba(15, 17, 38, 0.04);
}
.vdemo-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(15, 17, 38, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 17, 38, 0.05) 1px, transparent 1px);
  background-size: 36px 36px;
  mask: radial-gradient(circle at center, #000 55%, transparent 100%);
  -webkit-mask: radial-gradient(circle at center, #000 55%, transparent 100%);
}
.vdemo-trail {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  pointer-events: none;
}
.vdemo-ball {
  position: absolute;
  width: 34px; height: 34px;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 30%, #fef3c7, #f59e0b 65%, #b45309 100%);
  box-shadow:
    0 0 0 1px rgba(180, 83, 9, 0.3),
    0 0 24px rgba(245, 158, 11, 0.45),
    0 0 50px rgba(245, 158, 11, 0.18);
  transform: translate(-50%, -50%);
  left: 12%; top: 50%;
}
.vdemo-gt {
  position: absolute;
  left: 10px; bottom: 10px;
  display: inline-flex; align-items: center; gap: 8px;
  padding: 5px 12px;
  background: rgba(15, 17, 38, 0.85);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  border-radius: 999px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.vdemo-gt i { font-size: 0.6rem; color: var(--ok); }
.vdemo-gt b { font-family: var(--font-mono); font-weight: 600; }

.dir-pills {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 999px;
}
.dir-pill {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 12px;
  background: transparent;
  border: 0;
  border-radius: 999px;
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--text-2);
  transition: all 0.18s;
}
.dir-pill:hover { color: var(--text); }
.dir-pill.active {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 2px 6px rgba(30, 58, 138, 0.25);
}
.dir-pill i { font-size: 0.76rem; }

/* right panel: balance height with the square animation on the left */
.vdemo-panel {
  display: flex; flex-direction: column;
  gap: 16px;
  align-self: stretch;
  justify-content: space-between;
}

/* Always-visible questions list */
.vdemo-qlist {
  display: flex; flex-direction: column;
  gap: 8px;
}
.vdemo-q-line {
  display: grid;
  grid-template-columns: 14px 28px 1fr;
  gap: 10px;
  align-items: center;
  padding: 10px 14px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
}
/* Q-line colors mirror the bar swatches below: blue = color, red = direction */
.vdemo-q-line.color-q {
  border-left: 3px solid #0891b2;
  padding-left: 11px;
  background: rgba(56, 189, 248, 0.08);
}
.vdemo-q-line.dir-q {
  border-left: 3px solid #e11d48;
  padding-left: 11px;
  background: rgba(225, 29, 72, 0.05);
}
.vdemo-q-pin {
  display: grid; place-items: center;
  font-size: 0.5rem;
}
.vdemo-q-line.color-q .vdemo-q-pin { color: #0891b2; }
.vdemo-q-line.dir-q   .vdemo-q-pin { color: #e11d48; }
.vdemo-q-num {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.vdemo-q-text {
  font-size: 0.94rem;
  color: var(--text);
  line-height: 1.35;
}

/* Reveal CTA */
.vdemo-reveal-btn {
  display: grid;
  grid-template-columns: 36px 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 12px 16px;
  background: var(--grad);
  color: #fff;
  border: 0;
  border-radius: var(--radius-s);
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: -0.005em;
  cursor: pointer;
  transition: transform 0.18s, box-shadow 0.18s, opacity 0.18s;
  box-shadow: 0 6px 18px rgba(30, 58, 138, 0.22);
}
.vdemo-reveal-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 24px rgba(30, 58, 138, 0.3);
}
.vdemo-reveal-btn.is-active {
  background: var(--bg-soft);
  color: var(--text-2);
  box-shadow: none;
  border: 1px solid var(--border);
}
.vdemo-reveal-icon {
  display: grid; place-items: center;
  width: 32px; height: 32px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
  font-size: 0.78rem;
}
.vdemo-reveal-btn.is-active .vdemo-reveal-icon {
  background: rgba(15, 17, 38, 0.06);
  color: var(--text-2);
}
.vdemo-reveal-text {
  text-align: left;
}
.vdemo-reveal-hint {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0.7;
}
.vdemo-reveal-btn.is-active .vdemo-reveal-hint { opacity: 0.5; }

/* dual-bar overlap (paper Figure 1 style): color + direction on the same row,
   color behind, direction in front. */
.vdemo-bars-block {
  display: flex; flex-direction: column;
  gap: 14px;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.5s ease, opacity 0.4s ease 0.05s;
}
.vdemo-bars-block[data-revealed="true"] {
  max-height: 600px;
  opacity: 1;
}

.vdemo-legend {
  display: flex; flex-wrap: wrap; align-items: center;
  gap: 16px;
  padding: 0 4px 4px;
}
.vdemo-leg-item {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.84rem;
  color: var(--text);
}
.vdemo-leg-swatch {
  display: inline-block;
  width: 14px; height: 14px;
  border-radius: 4px;
}
.vdemo-leg-swatch.sw-color { background: rgba(56, 189, 248, 0.7); }
.vdemo-leg-swatch.sw-dir   { background: #e11d48; }
.vdemo-leg-text { font-weight: 500; }
.vdemo-leg-axis {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.vdemo-bars { display: flex; flex-direction: column; gap: 8px; }
.vdemo-row {
  display: grid;
  grid-template-columns: minmax(160px, 1.2fr) 2fr;
  gap: 16px;
  align-items: center;
  padding: 10px 14px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
}
.vdemo-row.ours {
  background: linear-gradient(90deg, rgba(30, 58, 138, 0.06), rgba(15, 118, 110, 0.04));
  border-color: rgba(30, 58, 138, 0.22);
  border-left: 3px solid var(--primary);
  padding-left: 11px;
}
.vdemo-name {
  font-size: 0.88rem;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.vdemo-row.ours .vdemo-name { font-weight: 500; }
.vdemo-row.ours .vdemo-name b { font-weight: 700; }

.vdemo-bar {
  position: relative;
  height: 14px;
  background: var(--bg-3);
  border-radius: 999px;
  overflow: hidden;
}
.vdemo-bar .fill-color,
.vdemo-bar .fill-dir {
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 0;
  border-radius: 999px;
  transition: width 1s cubic-bezier(.4,1,.4,1);
}
/* color sits BEHIND, light blue, semi-saturated */
.vdemo-bar .fill-color {
  background: rgba(56, 189, 248, 0.62);
  z-index: 1;
}
/* direction sits IN FRONT, red (or gradient for ours) */
.vdemo-bar .fill-dir {
  background: #e11d48;
  z-index: 2;
}
.vdemo-bar .fill-dir.strong {
  background: var(--grad);
  box-shadow: 0 0 12px rgba(30, 58, 138, 0.18);
}

.vdemo-val {
  font-family: var(--font-mono);
  font-size: 0.84rem;
  text-align: right;
  color: var(--text-2);
  font-weight: 600;
}
.vdemo-val.ours-val { color: var(--primary); font-weight: 700; }

.vdemo-foot {
  margin: 0;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.6;
  padding-top: 8px;
  border-top: 1px dashed var(--border-2);
}
.vdemo-foot a { color: var(--primary); border-bottom: 1px dotted var(--primary); }
.vdemo-foot a:hover { color: var(--primary-2); }

@media (max-width: 560px) {
  .vdemo-legend { gap: 10px; }
  .vdemo-leg-axis { margin-left: 0; flex-basis: 100%; }
  .vdemo-row { grid-template-columns: 1fr 44px; gap: 10px; padding: 10px 12px; }
  .vdemo-name { grid-column: 1 / -1; font-weight: 600; }
  .vdemo-bar { grid-column: 1 / 2; }
}

/* ===================== ABSTRACT ===================== */
.lead {
  font-size: 1.04rem;
  color: var(--text);
  margin: 0 0 28px;
  text-align: justify;
}
/* em inherits the global rule */

.tldr {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  padding: 18px 22px;
  background: #fff;
  border: 1px solid var(--border);
  border-left: 3px solid var(--primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}
.tldr-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--primary);
  align-self: start;
  padding-top: 4px;
}
.tldr p { margin: 0; color: var(--text); font-size: 0.96rem; }
/* em inherits the global rule */
.tldr mark {
  background: transparent;
  color: var(--primary);
  font-weight: 700;
  padding: 0 2px;
  border-bottom: 2px solid var(--primary);
}

/* ===================== FIGURES ===================== */
.figure-block {
  margin: 0;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow-1);
}
.figure-block img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-s);
  background: #fff;
  margin: 0 auto;
}
.figure-block figcaption {
  margin-top: 12px;
  padding: 0 6px;
  font-size: 0.88rem;
  color: var(--text-2);
  text-align: center;
}
/* em inherits the global rule */
.figure-block.tall img { height: 100%; object-fit: contain; max-height: 540px; }
.figure-block.wide { margin-top: 36px; }

/* Cap upscaling at native resolution so small figures stay crisp.
   The number = figure's native pixel width (with a small breathing margin). */
.figure-block.fig-sm img  { max-width: 640px; }
.figure-block.fig-md img  { max-width: 820px; }
.figure-block.fig-lg img  { max-width: 1080px; }

.grid-2 {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 18px;
  margin-top: 28px;
}
@media (max-width: 900px) { .grid-2 { grid-template-columns: 1fr; } }

/* Figure with text beside it (used for smaller charts) */
.fig-side {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 32px;
  align-items: center;
}
.fig-side .figure-block { margin: 0; }
.fig-side .figure-block img { max-width: 100%; }
.fig-side-text h4 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.15rem, 1.7vw, 1.35rem);
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--text);
}
.fig-side-text p {
  margin: 0 0 12px;
  font-size: 0.95rem;
  color: var(--text-2);
  line-height: 1.65;
}
.fig-side-text p:last-child { margin-bottom: 0; }
/* em inherits global rule */
.fig-side-text b { color: var(--text); }
.fig-side-stat {
  font-family: var(--font-mono);
  font-size: 1rem !important;
  padding: 10px 14px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  text-align: center;
  color: var(--text) !important;
}
.fig-side-stat .warn { color: var(--danger); font-weight: 600; }
.fig-side-stat .ok   { color: var(--ok);     font-weight: 600; }
.fig-side-aside {
  font-style: italic;
  color: var(--muted) !important;
  font-size: 0.9rem !important;
}
.fig-side-aside em { font-family: var(--font-serif); }
@media (max-width: 900px) {
  .fig-side { grid-template-columns: 1fr; gap: 22px; }
}

/* ===================== DIAGNOSIS — HEADLINE STAT ===================== */
.headline-stat {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  padding: 32px 36px 24px;
  margin: 8px 0 4px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-2);
}
.hs-side {
  display: flex; flex-direction: column;
  text-align: center;
  padding: 18px 12px;
  border-radius: var(--radius-s);
}
.hs-good { background: rgba(4, 120, 87, 0.05); }
.hs-bad  { background: rgba(185, 28, 28, 0.05); }
.hs-tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-2);
  margin-bottom: 12px;
}
.hs-num {
  display: block;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2rem, 3.6vw, 2.6rem);
  line-height: 0.95;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  margin-bottom: 8px;
}
.hs-good .hs-num { color: var(--ok); }
.hs-bad  .hs-num { color: var(--danger); }
.hs-num small {
  font-size: 0.42em;
  margin-left: 3px;
  font-weight: 700;
  vertical-align: top;
  position: relative; top: 0.5em;
  letter-spacing: -0.02em;
}
.hs-note {
  display: block;
  font-size: 0.98rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.45;
}
.hs-arrow {
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  color: var(--text-2);
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0;
  gap: 8px;
}
.hs-arrow .hs-break {
  font-family: inherit;
  font-style: normal;
  font-weight: 800;
  font-size: 1em;
  color: var(--danger);
  background: rgba(185, 28, 28, 0.1);
  padding: 1px 6px;
  border-radius: 4px;
  letter-spacing: -0.005em;
}
.hs-arrow svg { color: var(--danger); opacity: 1; }
.hs-foot {
  grid-column: 1 / -1;
  margin: 24px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.55;
}
.hs-foot b {
  color: var(--primary);
  font-weight: 700;
}
@media (max-width: 760px) {
  .headline-stat { grid-template-columns: 1fr; padding: 24px; }
  .hs-arrow { padding: 6px 0; }
}

/* ===================== DIAGNOSIS — CHAPTERS ===================== */
.chapter {
  margin-bottom: 84px;
  display: flex; flex-direction: column;
  gap: 24px;
}
.chapter:last-child { margin-bottom: 0; }
.chapter-head {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto auto;
  column-gap: 24px;
  row-gap: 10px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--border);
}
.chapter-no {
  grid-row: 1 / span 2;
  align-self: start;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2.2rem, 4vw, 2.9rem);
  line-height: 0.9;
  letter-spacing: -0.05em;
  font-variant-numeric: tabular-nums;
  color: var(--primary);
  opacity: 0.9;
}
.chapter-head h3 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.35rem, 2.4vw, 1.8rem);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--text);
}
.chapter-lead {
  margin: 0;
  font-size: 1rem;
  color: var(--text-2);
}
/* em inherits the global rule */

.chapter-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
@media (max-width: 700px) { .chapter-stats { grid-template-columns: 1fr; } }

.chapter-body, .chapter-foot, .chapter-takeaway {
  margin: 0;
  font-size: 1rem;
  color: var(--text);
  line-height: 1.72;
}
/* em inherits the global rule */
.chapter-foot { color: var(--text-2); }
.chapter-takeaway {
  padding: 22px 26px;
  background: rgba(30, 58, 138, 0.05);
  border-left: 3px solid var(--primary);
  border-radius: 0 var(--radius-s) var(--radius-s) 0;
  font-size: 1.02rem;
}

/* Tight one-line punchline. Slightly larger than body, centered, with the
   key phrase highlighted. Does NOT compete with the headline stat. */
.punchline {
  margin: 32px auto;
  max-width: 620px;
  text-align: center;
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.5;
  color: var(--text);
  letter-spacing: -0.005em;
}
.punchline .hit {
  color: var(--primary);
  font-weight: 700;
  background: linear-gradient(120deg, transparent 50%, rgba(67, 56, 202, 0.18) 50%);
  padding: 0 3px;
  border-radius: 2px;
}

.mini-stat {
  padding: 22px 24px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}
.mini-num {
  display: block;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2rem, 3.2vw, 2.5rem);
  line-height: 0.95;
  color: var(--primary);
  margin-bottom: 10px;
  letter-spacing: -0.045em;
  font-variant-numeric: tabular-nums;
}
.mini-num small {
  font-size: 0.42em;
  font-weight: 700;
  margin-left: 2px;
  vertical-align: top;
  position: relative; top: 0.5em;
  letter-spacing: -0.02em;
}
.mini-num.warn { color: var(--danger); }
.mini-num.ok { color: var(--ok); }
.mini-stat p {
  margin: 0;
  font-size: 0.94rem;
  color: var(--text-2);
}
.mini-stat p b { color: var(--text); }
/* em inherits the global rule */

/* SynBench 2x2 domain reference — visual anchor for "what is OOD" */
.domain-ref {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 40px;
  align-items: center;
  margin: 4px 0 8px;
}

.domain-ref-grid {
  display: grid;
  grid-template-columns: minmax(180px, 220px) minmax(180px, 220px);
  grid-template-rows: auto auto;
  grid-template-areas:
    "psyn  preal"
    "csyn  creal";
  gap: 10px;
}
.cell-psyn  { grid-area: psyn; }
.cell-preal { grid-area: preal; }
.cell-csyn  { grid-area: csyn; }
.cell-creal { grid-area: creal; }

.domain-cell {
  position: relative;
  margin: 0;
  border-radius: var(--radius-s);
  overflow: hidden;
  background: #f7f8fb;
}
.domain-cell.source {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
}
.domain-cell img,
.domain-cell .domain-video {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}
.cell-name {
  position: absolute;
  top: 8px; left: 8px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: #fff;
  background: rgba(15, 17, 38, 0.78);
  border-radius: 999px;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.cell-tag {
  position: absolute;
  top: 8px; right: 8px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #fff;
  border-radius: 999px;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.cell-tag.src  { background: rgba(67, 56, 202, 0.92); }
.cell-tag.ood  { background: rgba(217, 119, 6, 0.92); }
.cell-tag.hard { background: rgba(185, 28, 28, 0.92); }

.domain-ref-text {
  display: flex; flex-direction: column;
  gap: 14px;
}
.domain-ref-text p {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.65;
  color: var(--text-2);
}
.domain-ref-text p b { color: var(--text); font-weight: 700; }

@media (max-width: 900px) {
  .domain-ref { grid-template-columns: 1fr; gap: 22px; }
}
@media (max-width: 560px) {
  .domain-ref-grid { grid-template-columns: 1fr 1fr; }
}

/* Interactive magnitude-knob demo (Ch3) */
.mag-demo {
  margin-top: 6px;
  padding: 24px 26px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}
.mag-bars { display: flex; flex-direction: column; gap: 16px; }
.mag-row {
  display: grid;
  grid-template-columns: minmax(190px, 1.1fr) 2fr 56px;
  gap: 16px;
  align-items: center;
  font-size: 0.92rem;
  transition: opacity 0.4s;
}
.mag-row .mag-label {
  color: var(--text);
  line-height: 1.35;
}
.mag-row .mag-label small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 2px;
}
.mag-row .mag-label b { color: var(--primary); font-weight: 700; }
.mag-bar {
  position: relative;
  height: 16px;
  background: var(--bg-3);
  border-radius: 999px;
  overflow: visible;
}
.mag-fill {
  position: absolute; inset: 0 auto 0 0;
  border-radius: 999px;
  transition: width 0.9s cubic-bezier(.4,1,.4,1);
}
.mag-fill.weak      { background: #cbd5e1; }
.mag-fill.mid       { background: #0f766e; }
.mag-fill.mid-faded { background: #0f766e; opacity: 0.45; }
.mag-fill.add {
  left: 60.5%;
  background: var(--grad);
  box-shadow: 0 0 12px rgba(67, 56, 202, 0.3);
}
.mag-val {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  text-align: right;
}
.mag-row-reveal { opacity: 0.55; }
.mag-row-reveal[data-on="true"] { opacity: 1; }

.mag-delta {
  position: absolute;
  top: -28px;
  left: calc(60.5% + 0.5 * (var(--add-w, 0%)));
  transform: translateX(-50%);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--primary);
  background: rgba(67, 56, 202, 0.1);
  padding: 2px 8px;
  border-radius: 999px;
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.3s 0.7s;
}
.mag-row-reveal[data-on="true"] .mag-delta { opacity: 1; }

/* causal-link header: intervention (knob) → outcome (bars below) */
.mag-causal {
  display: flex; align-items: center; justify-content: center;
  gap: 14px;
  margin-bottom: 22px;
  padding-bottom: 18px;
  border-bottom: 1px dashed var(--border);
  flex-wrap: wrap;
}
.mag-causal-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.mag-causal-label.out { color: var(--primary); }
.mag-causal-arrow {
  display: grid; place-items: center;
  width: 28px; height: 28px;
  border-radius: 50%;
  background: rgba(67, 56, 202, 0.1);
  color: var(--primary);
  font-size: 0.78rem;
}
.mag-causal-knob {
  display: flex; align-items: center; gap: 8px;
}
.mag-causal-knob .knob-end {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}
.knob-track {
  position: relative;
  width: 120px;
  height: 8px;
  background: var(--bg-3);
  border-radius: 999px;
  overflow: hidden;
}
.knob-fill {
  position: absolute; inset: 0;
  width: 0%;
  background: var(--grad);
  border-radius: 999px;
}

/* replay link inside the foot paragraph */
.mag-replay {
  display: inline-flex; align-items: center; gap: 6px;
  margin-left: 8px;
  padding: 4px 10px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--primary);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.18s;
}
.mag-replay:hover {
  background: rgba(67, 56, 202, 0.05);
  border-color: var(--primary);
}
.mag-replay i { font-size: 0.78rem; }

.mag-foot {
  margin: 22px 0 0;
  font-size: 0.96rem;
  line-height: 1.6;
  color: var(--text);
}
.mag-foot b { color: var(--primary); font-weight: 700; }

@media (max-width: 700px) {
  .mag-row { grid-template-columns: 1fr 56px; gap: 8px; }
  .mag-row .mag-label { grid-column: 1 / -1; }
  .mag-bar { grid-column: 1 / 2; }
}

/* ===================== METHOD ===================== */
.method-grid {
  display: grid;
  grid-template-columns: 0.85fr 1fr;
  gap: 28px;
  align-items: stretch;
}
.method-left { display: flex; }
.method-left .figure-block { width: 100%; display: flex; flex-direction: column; }
.method-left .figure-block img { flex: 1; object-fit: contain; max-height: 540px; }

/* right column: stretch the 4 step cards to match the figure's height */
.method-right { display: flex; flex-direction: column; }
.method-steps {
  list-style: none; padding: 0; margin: 0;
  display: flex; flex-direction: column;
  gap: 14px;
  flex: 1;
}
.method-steps li {
  flex: 1 1 0;
  min-height: 0;
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 14px;
  padding: 20px;
  align-items: center;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}
.step-no {
  display: grid; place-items: center;
  width: 36px; height: 36px;
  border-radius: 6px;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.92rem;
}
.method-steps h4 {
  margin: 0 0 4px;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 1.04rem;
  color: var(--text);
}
.method-steps p { margin: 0; font-size: 0.92rem; color: var(--text-2); }
.method-steps code {
  font-family: var(--font-mono);
  font-size: 0.84em;
  background: rgba(15, 118, 110, 0.08);
  padding: 1px 6px;
  border-radius: 4px;
  color: var(--accent);
}
/* equation block — keeps the formula on its own line, never wraps mid-symbol */
.method-eq {
  margin: 6px 0 0;
  padding: 4px 12px;
  text-align: center;
  background: rgba(67, 56, 202, 0.05);
  border: 1px solid rgba(67, 56, 202, 0.12);
  border-radius: 6px;
  overflow-x: auto;
  line-height: 1.4;
}
.method-eq code {
  display: inline-block;
  background: transparent;
  padding: 0;
  font-size: 0.88em;
  color: var(--primary);
  white-space: nowrap;
  line-height: 1.4;
}
.method-eq + p { margin-top: 6px; }
@media (max-width: 900px) { .method-grid { grid-template-columns: 1fr; } }

/* ===================== RESULTS ===================== */
.bars-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow-1);
}
.bars-tabs {
  display: flex; flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 22px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.bar-tab {
  padding: 7px 14px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-2);
  font-size: 0.84rem;
  font-weight: 500;
  transition: all 0.2s;
}
.bar-tab:hover { color: var(--text); }
.bar-tab.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}
.bars-legend {
  display: flex; flex-wrap: wrap;
  gap: 8px 18px;
  padding: 0 4px 16px;
  margin-bottom: 16px;
  border-bottom: 1px dashed var(--border-2);
}
.leg-item {
  display: inline-flex; align-items: center; gap: 7px;
  font-size: 0.82rem;
  color: var(--text-2);
}
.leg-sw {
  display: inline-block;
  width: 14px; height: 10px;
  border-radius: 3px;
  flex-shrink: 0;
}
.leg-sw.chance {
  background: repeating-linear-gradient(45deg, #cbd5e1, #cbd5e1 3px, transparent 3px, transparent 6px);
  background-color: var(--bg-3);
}
.leg-sw.baseline { background: #94a3b8; }
.leg-sw.closed   { background: #b45309; }
.leg-sw.related  { background: #94a3b8; opacity: 0.65; }
.leg-sw.tuned    { background: #0f766e; }
.leg-sw.ours     { background: var(--grad); }

.bars { display: flex; flex-direction: column; gap: 10px; }
.bar-row {
  display: grid;
  grid-template-columns: 260px 1fr 58px;
  gap: 14px;
  align-items: center;
  font-size: 0.9rem;
}
.bar-label { color: var(--text-2); }
.bar-row.ours .bar-label { color: var(--text); font-weight: 600; }
.bar-row.tuned .bar-label { color: var(--text); font-weight: 500; }
.bar-row.bar-chance .bar-label { color: var(--muted); font-style: italic; }
.bar-track {
  position: relative;
  height: 10px;
  background: var(--bg-3);
  border-radius: 999px;
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  background: #94a3b8;
  border-radius: 999px;
  width: 0;
  transition: width 0.85s cubic-bezier(.4,1,.4,1);
}
.bar-row.tuned   .bar-fill { background: #0f766e; }
.bar-row.ours    .bar-fill { background: var(--grad); box-shadow: 0 0 12px rgba(67, 56, 202, 0.2); }
.bar-row.closed  .bar-fill { background: #b45309; }
.bar-row.related .bar-fill { background: #94a3b8; opacity: 0.65; }
.bar-row.bar-chance .bar-fill {
  background: repeating-linear-gradient(45deg, #cbd5e1, #cbd5e1 4px, transparent 4px, transparent 8px);
}
.bar-value {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--text);
  text-align: right;
}
@media (max-width: 700px) {
  .bar-row { grid-template-columns: 1fr 56px; }
  .bar-row .bar-label { grid-column: 1 / -1; }
}

/* leaderboard styles removed — bar chart now covers full Table 1 */

/* ===================== CITE ===================== */
.bib {
  position: relative;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 20px;
  box-shadow: var(--shadow-1);
  margin-bottom: 18px;
}
.bib pre {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.65;
  color: var(--text);
  white-space: pre-wrap;
  word-break: break-word;
}
.bib-copy {
  position: absolute;
  top: 12px; right: 12px;
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 11px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--border-2);
  color: var(--text-2);
  font-size: 0.76rem;
  transition: all 0.18s;
}
.bib-copy:hover { color: var(--primary); border-color: var(--primary); }
.bib-copy.copied {
  background: rgba(4, 120, 87, 0.08);
  border-color: rgba(4, 120, 87, 0.4);
  color: var(--ok);
}
.cite-links {
  display: flex; gap: 8px; flex-wrap: wrap;
  justify-content: center;
}

/* ===================== FOOTER ===================== */
.foot {
  padding: 50px 0 60px;
  text-align: center;
  color: var(--muted);
  font-size: 0.86rem;
  background: #fff;
}
.foot p { margin: 0; }
.foot .tiny { margin-top: 6px; font-size: 0.78rem; opacity: 0.7; }

/* ===================== REVEAL ===================== */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.55s ease, transform 0.55s ease;
  will-change: opacity, transform;
}
.reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}