:root {
  --paper: #f6f2ea;
  --ink: #1f1c17;
  --accent: #1e3a8a;
  --accent-dark: #142a63;
  --accent-soft: rgba(30, 58, 138, 0.2);
  --warm: #f97316;
  --muted: #6b7280;
  --border: rgba(15, 23, 42, 0.12);
  --card: rgba(255, 255, 255, 0.85);
  --max: 1080px;
  --nav-h: 60px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}

body {
  margin: 0;
  font-family: "Source Serif 4", "Times New Roman", Times, serif;
  color: var(--ink);
  background-color: var(--paper);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* Paper-grid background: faint dot grid over a diagonal blue->orange wash */
.paper-grid {
  background-image:
    radial-gradient(rgba(30, 58, 138, 0.08) 1px, transparent 1px),
    linear-gradient(120deg, rgba(30, 58, 138, 0.06), rgba(249, 115, 22, 0.05));
  background-size: 18px 18px, cover;
  background-attachment: fixed, fixed;
}

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}
.container.narrow { max-width: 800px; }

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

/* ===== Top navigation ===== */
.topnav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(246, 242, 234, 0.82);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  height: var(--nav-h);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  font-family: "Cormorant Garamond", serif;
  font-weight: 700;
  font-size: 1.6rem;
  letter-spacing: 0.04em;
  color: var(--accent);
}
.nav-brand:hover { text-decoration: none; }
.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  color: var(--ink);
  font-size: 0.98rem;
  font-weight: 500;
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.nav-links a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
  text-decoration: none;
}
.nav-cta {
  background: var(--accent);
  color: #fff !important;
  padding: 7px 16px !important;
  border-radius: 999px;
  border-bottom: none !important;
}
.nav-cta:hover { background: var(--accent-dark); border-bottom: none !important; }

/* burger (mobile) — pure CSS toggle */
.nav-toggle, .nav-burger { display: none; }
.nav-burger {
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--ink);
  line-height: 1;
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 64px 0 44px;
}
.venue {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--warm);
  margin: 0 0 14px;
}
.title {
  font-family: "Cormorant Garamond", "Times New Roman", Times, serif;
  font-weight: 700;
  font-size: 3.4rem;
  line-height: 1.05;
  margin: 0 0 10px;
  letter-spacing: 0.005em;
  color: var(--ink);
}
.subtitle {
  font-family: "Cormorant Garamond", serif;
  font-weight: 600;
  font-size: 1.6rem;
  color: var(--accent);
  margin: 0 0 28px;
}
.authors {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 18px;
  margin-bottom: 6px;
  font-size: 1.08rem;
}
.author a { color: var(--ink); font-weight: 500; }
.author sup { color: var(--muted); }
.affiliations {
  color: var(--muted);
  font-size: 0.95rem;
  margin-bottom: 28px;
}
.affiliations p { margin: 4px 0; }
.affiliations .notes { font-size: 0.88rem; }
.affiliations .contact {
  margin-top: 12px;
  font-size: 0.92rem;
  color: var(--ink);
}
.affiliations .contact strong { color: var(--accent); }
.affiliations .internship {
  margin-top: 10px;
  font-size: 0.85rem;
  font-style: italic;
  color: var(--muted);
}
.affiliations code {
  background: rgba(255,255,255,0.7);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.85em;
}

/* ===== Link buttons ===== */
.links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}
.link-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--ink);
  color: #fff;
  padding: 10px 20px;
  border-radius: 999px;
  font-weight: 500;
  font-size: 0.95rem;
  transition: background 0.15s ease, transform 0.15s ease;
}
.link-btn:hover {
  background: var(--accent);
  text-decoration: none;
  transform: translateY(-1px);
}
.link-btn .icon { font-size: 1.05rem; line-height: 1; }

/* ===== Sections ===== */
.section { padding: 56px 0; }
.section.alt {
  background: linear-gradient(180deg, rgba(255,255,255,0.55), rgba(255,255,255,0.35));
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.section-title {
  font-family: "Cormorant Garamond", "Times New Roman", Times, serif;
  font-weight: 700;
  font-size: 2.3rem;
  text-align: center;
  margin: 0 0 32px;
  color: var(--ink);
}
.abstract {
  font-size: 1.1rem;
  text-align: justify;
  color: #2d2a24;
  margin: 0;
}

.teaser { padding-top: 40px; padding-bottom: 40px; }

figure { margin: 0; }
figure img,
figure video {
  width: 100%;
  height: auto;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: #ffffff;
  padding: 12px;
  box-shadow: 0 14px 32px rgba(15, 23, 42, 0.10);
  display: block;
}
figure video {
  padding: 0;
  background: #000;
}
.hero-video {
  aspect-ratio: 16 / 9;
  object-fit: contain;
}
figure.soft img {
  border-radius: 6px;
}

/* ===== Video grids ===== */
.video-grid {
  display: grid;
  gap: 22px;
  margin-top: 28px;
}
.video-grid.two { grid-template-columns: repeat(2, 1fr); }
.video-grid.three { grid-template-columns: repeat(3, 1fr); }
.video-grid figcaption { font-weight: 600; color: var(--ink); }

figcaption {
  margin-top: 14px;
  font-size: 0.95rem;
  color: var(--muted);
  text-align: center;
  line-height: 1.55;
}
.center-note {
  text-align: center;
  color: var(--muted);
  margin: -16px 0 28px;
}
/* Centered lead line that introduces a media grid (needs room above) */
.grid-lead {
  text-align: center;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.6;
  max-width: 760px;
  margin: 40px auto 18px;
}

/* ===== Contribution cards ===== */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 26px;
  box-shadow: 0 14px 32px rgba(15, 23, 42, 0.08);
}
.card h3 {
  font-family: "Cormorant Garamond", serif;
  font-weight: 700;
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 1.4rem;
}
.card p { margin: 0; font-size: 1rem; color: #2d2a24; }

/* ===== Demo grid ===== */
.demo-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}
.demo-grid figcaption { font-weight: 600; color: var(--ink); }

/* ===== BibTeX ===== */
.bibtex {
  background: #1f1c17;
  color: #f1ebe0;
  border-radius: 14px;
  padding: 22px 24px;
  overflow-x: auto;
  font-size: 0.9rem;
  line-height: 1.5;
  box-shadow: 0 14px 32px rgba(15, 23, 42, 0.12);
}
.bibtex code { font-family: "SF Mono", "Menlo", "Consolas", monospace; }

/* ===== Footer ===== */
.footer {
  padding: 32px 0;
  text-align: center;
  font-size: 0.88rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
}

/* ===== Responsive ===== */
@media (max-width: 820px) {
  .cards { grid-template-columns: 1fr; }
  .demo-grid { grid-template-columns: 1fr; }
  .video-grid.two,
  .video-grid.three { grid-template-columns: 1fr; }
  .title { font-size: 2.5rem; }
  .subtitle { font-size: 1.3rem; }

  .nav-burger { display: block; }
  .nav-links {
    position: absolute;
    top: var(--nav-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: rgba(246, 242, 234, 0.97);
    border-bottom: 1px solid var(--border);
    padding: 8px 24px 16px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
  }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 12px 0; border-bottom: none; }
  .nav-cta { display: inline-block; margin-top: 8px; }
  .nav-toggle:checked ~ .nav-links { max-height: 380px; }
}