:root {
  --bg: #f5f7f4;
  --surface: #ffffff;
  --surface-alt: #eef3ef;
  --ink: #15201a;
  --muted: #596760;
  --line: rgba(21, 32, 26, 0.12);
  --brand: #186544;
  --brand-dark: #10271a;
  --brand-soft: rgba(24, 101, 68, 0.12);
  --shadow: 0 18px 42px rgba(15, 34, 22, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: linear-gradient(180deg, #0f1f19 0%, #0f1f19 430px, var(--bg) 430px, var(--bg) 100%);
  color: var(--ink);
  font: 16px/1.6 "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  overflow-x: hidden;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
.container { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.skip-link {
  position: absolute; left: 16px; top: 8px; z-index: 1000; padding: 10px 14px; background: #fff; border-radius: 999px;
  transform: translateY(-180%); transition: transform .2s ease;
}
.skip-link:focus { transform: translateY(0); }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

.site-header {
  position: sticky; top: 0; z-index: 80; background: rgba(15,31,25,.86); backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.header-inner {
  min-height: 74px; display: flex; align-items: center; justify-content: space-between; gap: 16px; color: #fff;
}
.brand-wordmark { height: 28px; width: auto; }
.header-tag {
  padding: 7px 12px; border-radius: 999px; background: rgba(255,255,255,.08); font-size: 13px; color: rgba(255,255,255,.82);
}
.menu-toggle { display: none; border: 0; background: transparent; padding: 10px; cursor: pointer; }
.menu-toggle span { display: block; width: 24px; height: 2px; margin: 4px 0; background: #fff; border-radius: 999px; }
.site-nav { display: flex; align-items: center; gap: 18px; color: rgba(255,255,255,.82); }
.site-nav a { font-size: 14px; }
.nav-cta { padding: 11px 16px; border-radius: 999px; background: var(--brand); color: #fff; font-weight: 700; }

.hero { padding: 56px 0 34px; color: #fff; }
.hero-wrap {
  display: grid; grid-template-columns: 1.05fr .95fr; gap: 22px; align-items: center;
}
.hero-copy { max-width: 700px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; margin: 0 0 14px; padding: 7px 14px;
  border-radius: 999px; background: rgba(255,255,255,.08); color: rgba(255,255,255,.82); font-size: 13px;
}
h1 {
  margin: 0; font-size: clamp(34px, 4vw, 55px); line-height: 1.08; letter-spacing: -0.03em;
  word-break: keep-all; overflow-wrap: normal; max-width: 14em;
}
.hero-lead { margin: 16px 0 0; max-width: 680px; color: rgba(255,255,255,.8); font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 0 20px;
  border-radius: 999px; font-weight: 700; border: 1px solid transparent;
}
.btn-primary { background: #fff; color: #10271a; }
.btn-secondary { color: #fff; border-color: rgba(255,255,255,.16); background: rgba(255,255,255,.05); }

.hero-notes {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px;
}
.note-card {
  padding: 18px; border-radius: 22px; background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.08);
  min-height: 150px;
}
.note-card strong { display: block; margin-bottom: 10px; font-size: 20px; }
.note-card p { margin: 0; color: rgba(255,255,255,.76); }

.section { padding: 72px 0; }
.section-alt { background: var(--surface-alt); }
.section-head { max-width: 760px; margin-bottom: 28px; }
.section-kicker {
  margin: 0 0 10px; color: var(--brand); font-weight: 800; letter-spacing: .08em; text-transform: uppercase; font-size: 12px;
}
.section-head h2 { margin: 0; font-size: clamp(28px, 3vw, 42px); line-height: 1.15; }
.section-head p:last-child { margin: 12px 0 0; color: var(--muted); }

.source-layout { display: grid; grid-template-columns: 1fr .9fr; gap: 22px; align-items: stretch; }
.source-list { display: grid; gap: 14px; }
.source-card, .file-card, .version-strip, .footer-grid { border: 1px solid var(--line); border-radius: 24px; background: var(--surface); box-shadow: var(--shadow); }
.source-card { padding: 22px 22px 22px 70px; position: relative; }
.source-card span {
  position: absolute; left: 22px; top: 22px; display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 50%; background: var(--brand); color: #fff; font-size: 13px; font-weight: 800;
}
.source-card strong { display: block; margin-bottom: 6px; font-size: 20px; }
.source-card p { margin: 0; color: var(--muted); }
.source-visual {
  margin: 0; padding: 18px; border-radius: 24px; background: linear-gradient(180deg, #fff, #eef5ee);
  border: 1px solid var(--line); box-shadow: var(--shadow);
}
.source-visual img { border-radius: 18px; }
.source-visual figcaption { margin-top: 12px; color: var(--muted); font-size: 14px; }

.file-grid { display: grid; grid-template-columns: 1.05fr .95fr .95fr; gap: 16px; }
.file-card { padding: 22px; }
.file-card img { border-radius: 16px; margin-bottom: 14px; }
.file-card strong { display: block; font-size: 20px; margin-bottom: 6px; }
.file-card p { margin: 0; color: var(--muted); }

.version-strip {
  padding: 24px; display: grid; grid-template-columns: 1.2fr .8fr; gap: 18px; align-items: center;
}
.version-strip h2 { margin: 0; font-size: clamp(26px, 2.8vw, 36px); line-height: 1.15; }
.version-strip p { margin: 12px 0 0; color: var(--muted); }
.version-actions { display: flex; gap: 12px; flex-wrap: wrap; justify-content: flex-end; }

.faq-list { display: grid; gap: 12px; }
.faq-item { background: var(--surface); border: 1px solid var(--line); border-radius: 22px; overflow: hidden; box-shadow: var(--shadow); }
.faq-trigger {
  width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 22px;
  border: 0; background: transparent; font: inherit; text-align: left; cursor: pointer; color: var(--ink);
}
.faq-icon { width: 18px; height: 18px; position: relative; flex: 0 0 18px; }
.faq-icon::before, .faq-icon::after {
  content: ""; position: absolute; inset: 50% auto auto 50%; transform: translate(-50%, -50%); background: var(--brand); border-radius: 999px;
}
.faq-icon::before { width: 18px; height: 2px; }
.faq-icon::after { width: 2px; height: 18px; transition: opacity .2s ease; }
.faq-item[aria-expanded="true"] .faq-icon::after { opacity: 0; }
.faq-panel { padding: 0 22px 18px; color: var(--muted); }

.site-footer {
  padding: 34px 0 42px; background: #0f1813; color: rgba(255,255,255,.88);
  border-top: 1px solid rgba(255,255,255,.08);
}
.footer-grid {
  display: grid; grid-template-columns: 1fr 1fr .9fr; gap: 24px; align-items: start;
}
.footer-logo { width: 132px; height: auto; margin-bottom: 14px; }
.footer-brand p { margin: 0; color: rgba(255,255,255,.68); }
.footer-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.footer-links h3 { margin: 0 0 10px; font-size: 16px; }
.footer-links a { display: block; color: rgba(255,255,255,.72); margin-top: 8px; }
.footer-cta { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 18px; border-radius: 999px; background: #fff; color: #10271a; font-weight: 800; }
.footer-action p { margin: 12px 0 0; color: rgba(255,255,255,.68); }

@media (max-width: 980px) {
  .site-nav { display: none; position: absolute; left: 16px; right: 16px; top: 74px; flex-direction: column; padding: 16px; border-radius: 22px; background: #0f1813; border: 1px solid rgba(255,255,255,.08); }
  .site-nav.is-open { display: flex; }
  .menu-toggle { display: inline-flex; flex-direction: column; }
  .hero-wrap, .source-layout, .version-strip, .footer-grid { grid-template-columns: 1fr; }
  .file-grid { grid-template-columns: 1fr; }
  .version-actions { justify-content: flex-start; }
}

@media (max-width: 720px) {
  .hero { padding-top: 38px; }
  .hero-notes { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: 1fr; }
}