:root {
  --navy: #0f2942;
  --navy-light: #16395c;
  --teal: #0ea5a0;
  --teal-light: #e6f7f6;
  --purple: #7c3aed;
  --purple-light: #c4b5fd;
  --purple-tint: #f3edfc;
  --text: #1e293b;
  --muted: #5b6b7c;
  --bg: #ffffff;
  --panel: #f7f9fb;
  --border: #e2e8f0;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.55;
}
a { color: var(--teal); }

/* ---- Header / nav ---- */
header.site-header {
  background: var(--navy);
  color: white;
}
.navwrap {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  flex-wrap: wrap;
  gap: 10px;
}
.brand {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  color: white;
  text-decoration: none;
}
.brand span { color: var(--purple-light); }
nav.sitenav a {
  color: #cfe3ec;
  text-decoration: none;
  margin-left: 28px;
  font-size: 0.92rem;
  font-weight: 500;
}
nav.sitenav a:first-child { margin-left: 0; }
nav.sitenav a:hover { color: white; }
nav.sitenav a.active { color: var(--teal); font-weight: 700; }

/* ---- Home hero ---- */
.hero {
  background: linear-gradient(135deg, #ffffff 0%, var(--purple-tint) 45%, #e8f7f5 100%);
  padding: 68px 24px;
}
.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 52px;
  align-items: center;
}
.eyebrow {
  display: inline-block;
  background: var(--teal);
  color: white;
  border-radius: 999px;
  padding: 5px 16px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 22px;
}
h1 {
  font-size: 2.5rem;
  line-height: 1.15;
  margin: 0 0 16px;
  letter-spacing: -0.01em;
  color: var(--navy);
}
.hero p.sub-tagline {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--navy);
  margin: 0 0 18px;
}
.hero p.sub {
  font-size: 1.12rem;
  color: var(--muted);
  max-width: 520px;
  margin: 0 0 34px;
}
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 13px 26px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
}
.btn-primary { background: var(--navy); color: white; }
.btn-ghost { border: 1px solid var(--border); color: var(--navy); background: white; }

.hero-figure {
  background: white;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 12px 28px rgba(15, 41, 66, 0.08);
}
.hero-figure img {
  width: 100%;
  display: block;
  border-radius: 8px;
  border: 1px solid var(--border);
}
.hero-figure .caption {
  margin-top: 12px;
  font-size: 0.82rem;
  color: var(--muted);
  text-align: center;
}

/* ---- Inner page header (non-home pages) ---- */
.page-header {
  background: linear-gradient(135deg, #ffffff 0%, var(--purple-tint) 45%, #e8f7f5 100%);
  padding: 48px 24px;
  text-align: center;
}
.page-header h1 { margin-bottom: 10px; }
.page-header p {
  max-width: 640px;
  margin: 0 auto;
  color: var(--muted);
  font-size: 1.05rem;
}

/* ---- Main content ---- */
main { max-width: 1100px; margin: 0 auto; padding: 56px 24px; }
.lede {
  max-width: 720px;
  margin: 0 auto 56px;
  text-align: center;
  color: var(--muted);
  font-size: 1.05rem;
}
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 26px;
}
.card .tag {
  display: inline-block;
  background: var(--teal-light);
  color: var(--teal);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 6px;
  margin-bottom: 12px;
}
.card h3 { margin: 0 0 8px; font-size: 1.15rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.92rem; }

/* ---- Prose content (rules / faq / schedule text) ---- */
.prose { max-width: 820px; margin: 0 auto; }
.prose h2 {
  color: var(--navy);
  font-size: 1.5rem;
  margin: 48px 0 16px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}
.prose h2:first-child { border-top: none; margin-top: 0; padding-top: 0; }
.prose h3 {
  color: var(--navy);
  font-size: 1.15rem;
  margin: 28px 0 10px;
}
.prose p { margin: 0 0 14px; }
.prose ul, .prose ol { margin: 0 0 16px; padding-left: 24px; }
.prose li { margin-bottom: 6px; }

/* ---- Rules list ---- */
.rules-list { list-style: none; margin: 0; padding: 0; counter-reset: rule; }
.rules-list > li {
  counter-increment: rule;
  position: relative;
  padding: 16px 16px 16px 56px;
  margin-bottom: 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.rules-list > li::before {
  content: counter(rule);
  position: absolute;
  left: 14px;
  top: 16px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--navy);
  color: white;
  font-size: 0.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---- FAQ ---- */
.faq-group { margin-bottom: 8px; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 14px;
  overflow: hidden;
}
.faq-q {
  background: var(--panel);
  padding: 14px 18px;
  font-weight: 700;
  color: var(--navy);
}
.faq-a {
  padding: 14px 18px;
  border-top: 1px solid var(--border);
  border-left: 3px solid var(--teal);
}
.faq-a p:last-child { margin-bottom: 0; }

/* ---- Callout box ---- */
.callout {
  background: var(--purple-tint);
  border: 1px solid var(--purple-light);
  border-radius: 10px;
  padding: 18px 20px;
  margin: 0 0 24px;
}
.callout p:last-child { margin-bottom: 0; }
.callout strong { color: var(--purple); }

/* ---- Tables ---- */
.table-wrap { overflow-x: auto; margin-bottom: 24px; }
table.schedule {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}
table.schedule th {
  background: var(--navy);
  color: white;
  text-align: left;
  padding: 10px 14px;
  white-space: nowrap;
}
table.schedule td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
table.schedule tr:nth-child(even) td { background: var(--panel); }

/* ---- Challenge list (index page) ---- */
.challenge-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.challenge-card {
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px 26px;
  text-decoration: none;
  color: inherit;
}
.challenge-card:hover { border-color: var(--teal); }
.challenge-card .num {
  flex: 0 0 auto;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--navy);
  color: white;
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.challenge-card .body { flex: 1 1 auto; min-width: 0; }
.challenge-card h3 { margin: 0 0 4px; font-size: 1.15rem; color: var(--navy); }
.challenge-card p { margin: 0; color: var(--muted); font-size: 0.92rem; }
.challenge-card .status {
  flex: 0 0 auto;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 999px;
}
.status-active { background: var(--teal-light); color: var(--teal); }
.status-upcoming { background: var(--purple-tint); color: var(--purple); }
.status-complete { background: var(--panel); color: var(--muted); border: 1px solid var(--border); }

/* ---- Sponsor / partner bar ---- */
.sponsor-bar {
  border-top: 1px solid var(--border);
  padding: 48px 24px;
  text-align: center;
}
.sponsor-bar .label {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 26px;
}
.sponsor-bar .logos {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 56px;
}
.sponsor-bar .logos a { display: inline-flex; align-items: center; }
.sponsor-bar img { width: auto; }
.sponsor-bar img.logo-ihp { height: 136px; }
.sponsor-bar img.logo-waferspace { height: 136px; }
.sponsor-bar img.logo-chipfoundry { height: 170px; }
.sponsor-bar .vensa-wordmark {
  font-family: "Inter", -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-weight: 600;
  font-size: 3.9rem;
  color: var(--text);
  letter-spacing: -0.01em;
  text-decoration: none;
}
.sponsor-bar .vensa-wordmark:hover { color: var(--navy); }

/* ---- Leaderboard ---- */
table.leaderboard { width: 100%; border-collapse: collapse; font-size: 0.92rem; }
table.leaderboard th {
  background: var(--navy);
  color: white;
  text-align: left;
  padding: 10px 14px;
}
table.leaderboard td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
}
table.leaderboard tr:nth-child(even) td { background: var(--panel); }
table.leaderboard td.rank { font-weight: 700; color: var(--navy); width: 3em; }
table.leaderboard td.repo { color: var(--muted); font-style: italic; }

/* ---- Footer ---- */
footer.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 24px;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
}
footer.site-footer a { color: var(--muted); }

@media (max-width: 760px) {
  .hero-inner { grid-template-columns: 1fr; }
  .cards { grid-template-columns: 1fr; }
  nav.sitenav a { margin-left: 16px; }
}