/* ═══════════════════════════════════════════════════════════
   Discrete Flow Maps — Stylesheet
   Color palette from mean_denoiser.py / stochastic_interpolant_frame.py
   ═══════════════════════════════════════════════════════════ */

:root {
  --bg:           #ffffff;
  --ink:          #2e4552;
  --teal:         #2f533f;
  --maroon:       #965c58;
  --simplex-fill: #f2eee0;
  --box-edge:     #c3c3c3;
  --cloud:        #90a0aa;
  --gold:         #d4a843;
  --green-1:      #2f533f;
  --green-2:      #3d604c;
  --green-3:      #4c6b5a;

  --font-body:  'Inter', 'Helvetica Neue', system-ui, sans-serif;
  --font-mono:  'JetBrains Mono', 'SF Mono', 'Consolas', monospace;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  font-size: clamp(17px, 1.25vw, 22px);
}

::selection {
  background: rgba(47, 83, 63, 0.15);
}

/* ═══════════════════════════════════════════════════════════
   HERO
   ═══════════════════════════════════════════════════════════ */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 3rem 2rem;
}

.hero__inner {
  max-width: 680px;
  text-align: center;
}

.hero__eyebrow {
  font-size: 0.8em;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--cloud);
  margin-bottom: 1.2rem;
  font-weight: 500;
}

.hero__title {
  font-size: clamp(2.6rem, 5.5vw, 4.8rem);
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.hero__authors {
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

.hero__author-names {
  font-size: 0.95em;
  font-weight: 500;
  color: var(--ink);
  line-height: 1.6;
}

.hero__author-names sup {
  font-size: 0.65em;
  color: var(--cloud);
}

.hero__affiliations {
  font-size: 0.78em;
  color: var(--cloud);
  margin-top: 0.35rem;
  font-style: italic;
  line-height: 1.6;
}

.hero__affiliations sup {
  font-size: 0.7em;
  font-style: normal;
}

.hero__rule {
  width: 60px;
  height: 3px;
  background: var(--teal);
  margin: 1.8rem auto;
  border-radius: 2px;
}

.hero__abstract {
  font-size: 1em;
  color: var(--ink);
  opacity: 0.8;
  line-height: 1.75;
  max-width: 580px;
  margin: 0 auto 2rem;
}

.hero__abstract em {
  font-style: italic;
  color: var(--teal);
  font-weight: 500;
}

.hero__links {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 3rem;
}

.hero__link {
  display: inline-block;
  padding: 0.55rem 1.6rem;
  border: 1.5px solid var(--ink);
  border-radius: 6px;
  color: var(--ink);
  text-decoration: none;
  font-size: 0.85em;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: background 0.2s, color 0.2s;
}

.hero__link:hover {
  background: var(--ink);
  color: var(--bg);
}

.hero__scroll-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  color: var(--cloud);
  font-size: 0.75em;
  letter-spacing: 0.04em;
  animation: float 2.5s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(6px); }
}

/* ═══════════════════════════════════════════════════════════
   SIMPLEX GROUP — shared sticky canvas for theory sections
   ═══════════════════════════════════════════════════════════ */

.simplex-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  position: relative;
  border-top: 1px solid rgba(46, 69, 82, 0.08);
}

.simplex-text-column {
  padding: 0 clamp(2rem, 5vw, 5rem);
}

.text-section {
  /* Container for scroll steps within the shared group */
}

/* ═══════════════════════════════════════════════════════════
   SCROLL SECTIONS — two-column sticky layout (parallel, steering)
   ═══════════════════════════════════════════════════════════ */

.scroll-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  position: relative;
  border-top: 1px solid rgba(46, 69, 82, 0.08);
}

/* Text track: scrolls naturally */
.scroll-text-track {
  padding: 0 clamp(2rem, 5vw, 5rem);
}

/* Each step fills a compact viewport height */
.scroll-step {
  min-height: 55vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 2rem 2.8rem 2rem 0.5rem;
  border-left: 3px solid transparent;
  border-radius: 0 8px 8px 0;
  background: transparent;
  overflow: hidden;
  opacity: 0.15;
  transform: translateY(12px);
  transition: opacity 0.55s ease, transform 0.55s ease,
              background 0.5s ease, border-color 0.5s ease;
}

.scroll-step.is-active {
  opacity: 1;
  transform: translateY(0);
  background: var(--simplex-fill);
  border-left-color: var(--teal);
}

.scroll-step:first-child {
  padding-top: 10vh;
}

.scroll-step:last-child {
  padding-bottom: 10vh;
}

/* Sticky canvas column */
.scroll-canvas-sticky {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.scroll-canvas-sticky canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* ── Text styling inside steps ── */

.scroll-step h2 {
  font-size: clamp(1.6rem, 2.8vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.6rem;
  color: var(--ink);
}

.scroll-step p {
  margin-bottom: 0.5rem;
  max-width: 520px;
}

.scroll-step p:last-child {
  margin-bottom: 0;
}

.scroll-step strong {
  font-weight: 600;
}

.scroll-step em {
  font-style: italic;
}

.display-math {
  margin: 0.8rem 0;
}

/* ═══════════════════════════════════════════════════════════
   RESULTS
   ═══════════════════════════════════════════════════════════ */

.results-section {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
  border-top: 1px solid rgba(46, 69, 82, 0.08);
}

.results-inner {
  max-width: 680px;
  text-align: center;
}

.results-inner h2 {
  font-size: clamp(1.5rem, 2.5vw, 2.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.results-inner p {
  color: var(--cloud);
  font-size: 1em;
}

/* ═══════════════════════════════════════════════════════════
   FOOTER
   ═══════════════════════════════════════════════════════════ */

.site-footer {
  padding: 5rem 2rem 3rem;
  text-align: center;
  border-top: 1px solid rgba(46, 69, 82, 0.08);
}

.citation-box {
  background: var(--simplex-fill);
  border: 1px solid var(--box-edge);
  border-radius: 10px;
  padding: 1.8rem 2rem;
  max-width: 560px;
  margin: 0 auto 2rem;
  text-align: left;
  position: relative;
}

.citation-box h3 {
  font-size: 0.85em;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--cloud);
  margin-bottom: 0.8rem;
}

.citation-box pre {
  font-family: var(--font-mono);
  font-size: 0.82em;
  line-height: 1.6;
  white-space: pre-wrap;
  color: var(--ink);
}

.copy-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: var(--bg);
  border: 1px solid var(--box-edge);
  border-radius: 5px;
  padding: 0.3rem 0.7rem;
  font-family: var(--font-body);
  font-size: 0.72em;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  transition: background 0.15s;
}

.copy-btn:hover {
  background: var(--simplex-fill);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  margin-bottom: 2rem;
}

.footer-links a {
  color: var(--ink);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9em;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.footer-links a:hover {
  border-color: var(--ink);
}

.footer-note {
  color: var(--cloud);
  font-size: 0.75em;
}

/* ═══════════════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════════════ */

@media (max-width: 900px) {
  .simplex-group,
  .scroll-section {
    grid-template-columns: 1fr;
  }

  .simplex-group > .scroll-canvas-sticky,
  .scroll-canvas-sticky {
    height: 50vh;
    position: sticky;
    top: 0;
    order: -1; /* canvas on top */
  }

  .scroll-step {
    min-height: 45vh;
  }

  .simplex-text-column,
  .scroll-text-track {
    padding: 0 1.5rem;
  }
}

/* ═══════════════════════════════════════════════════════════
   KATEX OVERRIDES
   ═══════════════════════════════════════════════════════════ */

.katex-display {
  margin: 0.6em 0;
}

.katex {
  font-size: 1.2em;
}

.display-math .katex-display {
  font-size: 1.10em;
}