:root {
  --fg: #1a1a1a;
  --muted: #666;
  --accent: #ee4c2c;
  --bg: #ffffff;
  --card: #f7f7f8;
  --border: #e5e5e8;
  --maxw: 860px;
}

* { box-sizing: border-box; }

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

.hero {
  text-align: center;
  padding: 3.5rem 1.25rem 2.5rem;
  border-bottom: 1px solid var(--border);
}
.hero-img {
  display: block;
  width: 100%;
  max-width: 760px;
  height: auto;
  margin: 0 auto 1rem;
}
.hero h1 {
  font-size: 3rem;
  margin: 0;
  letter-spacing: 0.02em;
}
.subtitle { font-size: 1.25rem; margin: 0.4rem 0 0; color: var(--fg); }
.venue { color: var(--fg); font-weight: 600; margin: 0.6rem 0 0; }
.authors { color: var(--muted); margin: 0.8rem 0 1.4rem; }

.links { display: flex; gap: 0.6rem; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: var(--fg);
  color: #fff;
  text-decoration: none;
  border-radius: 999px;
  font-size: 0.95rem;
  transition: opacity 0.15s;
}
.btn:hover { opacity: 0.85; }

main { max-width: var(--maxw); margin: 0 auto; padding: 2rem 1.25rem; }
section { margin-bottom: 3rem; }
.intro p { font-size: 1.12rem; color: #333; margin-top: 0.5rem; }
h2 {
  font-size: 1.5rem;
  border-bottom: 2px solid var(--border);
  padding-bottom: 0.3rem;
}
.hint, .empty { color: var(--muted); }
.empty { background: var(--card); padding: 1rem; border-radius: 8px; }
code { background: var(--card); padding: 0.15em 0.4em; border-radius: 4px; font-size: 0.9em; }

/* Audio sample cards */
.sample {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
}
.sample h3 { margin: 0 0 0.75rem; font-size: 1.1rem; }
.tracks { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.75rem; }
.track { display: flex; flex-direction: column; gap: 0.3rem; }
.track.full { grid-column: 1 / -1; }
@media (max-width: 520px) { .tracks { grid-template-columns: 1fr; } }
.track .label { font-size: 0.85rem; color: var(--muted); font-weight: 600; }
.track audio { width: 100%; }

/* Tables */
table.tiers { border-collapse: collapse; width: 100%; max-width: 420px; }
table.tiers th, table.tiers td { border: 1px solid var(--border); padding: 0.5rem 0.75rem; text-align: left; }
table.tiers th { background: var(--card); }

.bibtex {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  overflow-x: auto;
  font-size: 0.85rem;
}

footer {
  text-align: center;
  padding: 2rem 1.25rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
}
footer a { color: var(--muted); }