/* ─── Page hero ───────────────────────────────────────── */
.os-page-hero {
  padding: 140px 40px 80px;
  border-bottom: 1px solid var(--card-border);
}
.os-hero-heading {
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.08;
  margin-bottom: 20px;
  max-width: 700px;
}
.os-hero-sub {
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 640px;
  margin-bottom: 32px;
}
.os-github-btn { gap: 9px; }

/* ─── Sections ────────────────────────────────────────── */
.os-section { padding: 80px 40px; }
.os-section-alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--card-border);
  border-bottom: 1px solid var(--card-border);
  transition: background 0.2s;
}

/* ─── Two-column layout ───────────────────────────────── */
.os-two-col {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 80px;
  align-items: start;
}
.os-body { font-size: 15px; color: var(--text-muted); line-height: 1.7; }
.os-body p { margin-bottom: 16px; }
.os-body p:first-child { margin-top: 0; }

.os-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin: 16px 0 20px;
  padding: 0;
}
.os-list li {
  padding-left: 20px;
  position: relative;
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}
.os-list li::before {
  content: '–';
  position: absolute;
  left: 0;
  color: var(--orange-bright);
}
.os-list li strong { color: var(--text); font-weight: 600; }

.os-body-note {
  font-size: 13px;
  color: var(--text-dim);
  margin-top: 20px;
}
.os-body-note a {
  color: var(--text-dim);
  text-decoration: underline;
}
.os-body-note a:hover { color: var(--orange-bright); }

/* ─── Contribute cards ────────────────────────────────── */
.os-card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin-top: 48px;
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--card-border);
}
.os-card {
  background: var(--card-bg);
  padding: 28px 24px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: background 0.2s;
}
.os-card:hover { background: var(--feat-hover); }
.os-card-icon {
  width: 40px; height: 40px;
  background: rgba(217,79,0,0.1);
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 4px;
  color: var(--orange-bright);
}
.os-card h3 { font-size: 15px; font-weight: 600; }
.os-card p { font-size: 13.5px; color: var(--text-muted); line-height: 1.6; flex: 1; }
.os-card-link {
  font-size: 13px;
  font-weight: 500;
  color: var(--orange-bright);
  margin-top: 4px;
}

/* ─── Alpha box ───────────────────────────────────────── */
.os-alpha-box {
  max-width: 700px;
}
.os-alpha-box .s-heading { margin-bottom: 20px; }
.os-alpha-body {
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}
.os-alpha-body a {
  color: var(--orange-bright);
  text-decoration: none;
}
.os-alpha-body a:hover { text-decoration: underline; }
.os-alpha-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 28px;
}

/* ─── Responsive ───────────────────────────────────────── */
@media (max-width: 820px) {
  .os-page-hero { padding: 110px 20px 60px; }
  .os-section { padding: 60px 20px; }
  .os-two-col { grid-template-columns: 1fr; gap: 32px; }
  .os-card-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 500px) {
  .os-card-grid { grid-template-columns: 1fr; }
  .os-alpha-actions { flex-direction: column; }
}