:root {
  --bg: #ffffff;
  --panel: #f6f7f9;
  --fg: #222426;       /* headings / strong text — soft near-black, not pure #000 */
  --body: #3f4448;     /* body copy — neutral warm-grey, easy on the eyes */
  --muted: #71757b;
  --accent: #3056d3;   /* calmer blue, less neon */
  --border: #e4e7eb;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--body);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Hero ---------- */
.hero {
  text-align: center;
  padding: 4rem 1.5rem 2.5rem;
  border-bottom: 1px solid var(--border);
}
.hero-logo {
  width: 88px;
  height: 88px;
  /* border-radius: 20px; */
  display: block;
  margin: 0 auto 1.25rem;
}
.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem 0;
  color: var(--fg);
}
.subtitle {
  font-size: clamp(1.3rem, 2.6vw, 1.75rem);
  font-weight: 500;
  margin: 0 auto 1.5rem;
  color: var(--fg);
}
.authors { margin: 0.5rem 0 0.35rem; font-size: 1.25rem; }
.affiliations { color: var(--muted); margin: 0 0 0.35rem; font-size: 1.1rem; }
.notes { color: var(--muted); margin: 0 0 1.5rem; font-size: 1rem; }

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.1rem;
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--fg);
  color: #fff;
  font-weight: 500;
  transition: background 0.15s ease;
}
.btn:hover { background: #000; text-decoration: none; }

/* ---------- Main: full-width alternating bands ---------- */
.band { padding: 3.5rem 1.5rem; }
.band-alt { background: var(--panel); }
.container {
  max-width: 1100px;
  margin: 0 auto;
}
.container.wide { max-width: 1280px; }
h2 {
  font-size: 1.75rem;
  font-weight: 600;
  text-align: center;
  margin: 0 0 1.5rem;
  color: var(--fg);
}
.abstract p {
  max-width: 52rem;
  margin: 0 auto;
  text-align: justify;
  color: var(--body);
}

.tldr {
  max-width: 52rem;
  margin: 0 auto;
  text-align: left;
  font-size: 1.2rem;
  line-height: 1.6;
  color: var(--fg);
}
.tldr strong { color: var(--accent); font-weight: 700; }
.tldr b { color: var(--accent); font-weight: 700; }

/* ---------- Video gallery (rendered from videos.yaml by gallery.js) ---------- */
.gallery-error {
  max-width: 52rem;
  margin: 0 auto;
  padding: 1rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel);
  color: var(--muted);
  text-align: center;
}

/* In-page section nav */
.gallery-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  justify-content: center;
  margin: 0 0 2.5rem;
}
.gallery-nav a {
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg);
  color: var(--body);
  font-size: 0.9rem;
  font-weight: 500;
}
.gallery-nav a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.gallery-upcoming {
  margin: -1rem 0 2.5rem;
  color: var(--accent);
  font-size: 1.35rem;
  font-weight: 700;
  text-align: center;
}

/* Section */
.video-section { margin-bottom: 3.5rem; scroll-margin-top: 1rem; }
.video-section h2 { text-align: left; margin: 0 0 0.6rem; }
.video-section .prompt-hint {
  margin: 0 0 1rem;
  color: var(--fg);
  font-size: 1rem;
  font-weight: 500;
}
.video-section .lead {
  color: var(--muted);
  max-width: 60rem;
  margin: 0 0 1.5rem;
  font-size: 1rem;
}

/* Speed toggle */
.speed-bar {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 1.4rem;
  font-size: 0.9rem;
  color: var(--muted);
}
.speed-btn {
  padding: 0.3rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg);
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--body);
  font-weight: 500;
  transition: all 0.15s ease;
}
.speed-btn:hover { border-color: #bbb; }
.speed-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* Grid */
.grid { display: grid; gap: 1.25rem; }
.grid.cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 1000px) {
  .grid.cols-3, .grid.cols-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .grid.cols-2, .grid.cols-3, .grid.cols-4 { grid-template-columns: 1fr; }
}

/* Video card */
.vcard { display: flex; flex-direction: column; }
.vmedia {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  background: #000;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 4px 16px rgba(0, 0, 0, 0.06);
  aspect-ratio: 16 / 9;
}
.vcard video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: #000;
}
.prompt-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  color: #fff;
  padding: 10px;
  margin: auto;
  opacity: 0;
  transition: opacity 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-size: 9pt;
  line-height: 1.4;
  white-space: pre-line;
  overflow-y: auto;
  z-index: 4;
  pointer-events: none;
}
.vmedia:hover .prompt-overlay { opacity: 1; }
.duration-tag {
  position: absolute;
  top: 12px;
  right: 12px;
  padding: 4px 11px;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.65);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  z-index: 3;
  pointer-events: none;
}
.col-label {
  position: absolute;
  top: 12px;
  left: 12px;
  padding: 4px 12px;
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.65);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  z-index: 3;
  pointer-events: none;
}
.col-label.ours { background: var(--accent); }

/* Comparison row */
.compare-row { margin-bottom: 3rem; }
.compare-row .row-title {
  font-size: 1rem;
  color: var(--muted);
  margin: 0 0 0.75rem;
  font-weight: 500;
}

/* Prompt block */
.prompt-block {
  margin-top: 0.85rem;
  padding: 0.9rem 1.1rem;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--body);
}
.prompt-block p { margin: 0; }
.prompt-block .seg {
  display: flex;
  gap: 0.9rem;
  align-items: flex-start;
  padding: 0.5rem 0;
  border-bottom: 1px dashed var(--border);
}
.prompt-block .seg:last-child { border-bottom: none; }
.prompt-block .seg-time {
  flex: 0 0 auto;
  min-width: 90px;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  padding-top: 1px;
}
.prompt-block .seg-text { flex: 1; color: var(--body); }

/* ---------- Figures (rendered from figures.yaml by figures.js) ---------- */
/* Cap + center the figure area so every section shares one width. */
#figure-gallery {
  --figure-maxw: 60rem;
  max-width: var(--figure-maxw);
  margin: 0 auto;
}
.figure-section { margin-bottom: 3rem; }
.figure-section:last-child { margin-bottom: 0; }
.figure-section h2 { margin: 0 0 1.5rem; }
.figure-section .figure-body {
  color: var(--body);
  max-width: 60rem;
  margin: 1.25rem 0 0;   /* sits below the images */
  white-space: pre-line; /* keep line breaks written with YAML's `|` block style */
}
.figure { margin: 0; display: flex; flex-direction: column; }
.figure img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
}
/* Dashed box shown when an image fails to load. */
.figure img.img-missing {
  min-height: 160px;
  padding: 1rem;
  border-style: dashed;
  background: var(--panel);
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}
.figure figcaption {
  margin-top: 0.6rem;
  font-size: 1.rem;
  line-height: 1.5;
  color: var(--muted);
  text-align: center;
  overflow-wrap: anywhere;
}

/* Equal-height row (equal_height: true): images on one row at the same height;
   figures.js sets flex-grow per image from its aspect ratio. */
.grid.equal-height {
  display: flex;
  flex-wrap: nowrap;
  align-items: flex-start;
}
.grid.equal-height .figure {
  flex: 1 1 0;
  min-width: 0;
}
.grid.equal-height .figure img {
  width: 100%;
  height: auto;
}

/* ---------- BibTeX ---------- */
.bibtex pre {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  font-size: 0.85rem;
}
.bibtex code { color: var(--body); font-family: "SFMono-Regular", Consolas, monospace; }

/* ---------- Footer ---------- */
footer {
  text-align: center;
  padding: 2rem 1.5rem;
  color: var(--muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--border);
}