:root {
  --bg: #121517;
  --panel: #191B1D;
  --panel-2: #202427;
  --ink: #F2F4F5;
  --muted: #9AA1A7;
  --accent: #E65F22;
  --accent-strong: #C84A10;
  --good: #5BC08A;
  --warn: #E6B84B;
  --line: rgba(255, 255, 255, .09);
  --line-soft: rgba(255, 255, 255, .06);
  --radius: 14px;
  --maxw: 1120px;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img, svg { display: block; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }

/* header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(18, 21, 23, .88);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line-soft);
}
.nav { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.02rem; letter-spacing: .01em; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.brand .brand-en { color: var(--muted); font-weight: 600; font-size: .8rem; }
.nav-links { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav-links a { padding: 8px 12px; border-radius: 10px; color: var(--muted); font-size: .94rem; }
.nav-links a:hover { color: var(--ink); background: var(--panel-2); }
.nav-links .btn { padding: 9px 16px; font-size: .92rem; }
.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: transparent;
  color: var(--ink);
  font-size: 1.2rem;
  cursor: pointer;
}

/* buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 1.02rem;
  line-height: 1.1;
  padding: 15px 24px;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: transform .12s ease, background-color .12s ease, border-color .12s ease, color .12s ease;
}
.btn:active { transform: scale(.98); }
.btn-primary { background: var(--accent-strong); color: #FFFFFF; }
.btn-primary:hover { background: #B8440F; }
.btn-ghost { border-color: var(--line); color: var(--ink); background: transparent; }
.btn-ghost:hover { border-color: var(--accent); }
.btn[disabled] { opacity: .55; cursor: not-allowed; }

/* hero */
.hero { min-height: 100dvh; display: flex; align-items: center; padding: 72px 0 64px; }
.hero-inner { display: grid; grid-template-columns: 1.05fr .95fr; gap: 56px; align-items: center; }
.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--accent);
  font-weight: 700;
  font-size: .9rem;
  margin: 0 0 18px;
}
.kicker::before { content: ""; width: 18px; height: 3px; background: var(--accent); border-radius: 2px; }
.hero h1 { margin: 0 0 20px; font-size: clamp(2.15rem, 5vw, 3.4rem); line-height: 1.12; letter-spacing: -.01em; font-weight: 900; }
.hero .lead { color: var(--muted); font-size: 1.08rem; max-width: 34em; margin: 0 0 32px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-notes { display: flex; gap: 8px 24px; flex-wrap: wrap; margin-top: 36px; color: var(--muted); font-size: .9rem; }
.hero-notes span::before { content: "✓"; color: var(--good); margin-right: 7px; font-weight: 700; }

.diagram-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  padding: 18px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, .35);
}
.diagram-wrap svg { width: 100%; height: auto; }
.diagram-caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
  color: var(--muted);
  font-size: .82rem;
}
.diagram-caption .tag { color: var(--accent); font-weight: 700; }

/* sections */
section { padding: 92px 0; }
.section-head { max-width: 660px; margin-bottom: 52px; }
.section-head h2 { margin: 0 0 12px; font-size: clamp(1.6rem, 3.4vw, 2.3rem); line-height: 1.2; letter-spacing: -.01em; font-weight: 900; }
.section-head p { margin: 0; color: var(--muted); font-size: 1.02rem; }

/* features */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}
.feature { background: var(--bg); padding: 30px 28px; }
.feature h3 { margin: 0 0 8px; font-size: 1.08rem; font-weight: 800; display: flex; align-items: center; gap: 11px; }
.feature h3::before { content: ""; width: 8px; height: 8px; background: var(--accent); border-radius: 2px; flex: none; }
.feature p { margin: 0; color: var(--muted); font-size: .95rem; }

/* scenarios */
.scenario-list { display: grid; grid-template-columns: 1fr 1fr; gap: 6px 44px; }
.scenario { display: flex; gap: 12px; padding: 12px 0; align-items: baseline; }
.scenario::before { content: "✓"; color: var(--good); font-weight: 700; flex: none; }
.scenario b { font-weight: 700; white-space: nowrap; }
.scenario span { color: var(--muted); font-size: .92rem; }

/* workflow steps */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.step { background: var(--panel); border: 1px solid var(--line-soft); border-radius: var(--radius); padding: 24px 22px; }
.step .num { font-family: var(--mono); color: var(--accent); font-weight: 700; font-size: .85rem; }
.step h3 { margin: 12px 0 6px; font-size: 1rem; font-weight: 800; }
.step p { margin: 0; color: var(--muted); font-size: .88rem; }

/* trust */
.trust-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}
.trust-grid > div { background: var(--bg); padding: 24px 22px; }
.trust-grid b { display: block; font-size: 1rem; margin-bottom: 5px; }
.trust-grid span { color: var(--muted); font-size: .86rem; line-height: 1.55; }

/* cta */
.cta-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  flex-wrap: wrap;
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 52px 48px;
}
.cta-panel h2 { margin: 0 0 8px; font-size: clamp(1.4rem, 3vw, 2rem); line-height: 1.2; }
.cta-panel p { margin: 0; color: var(--muted); }

/* footer */
.site-footer { border-top: 1px solid var(--line-soft); padding: 48px 0 56px; color: var(--muted); font-size: .9rem; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 36px; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 800; color: var(--ink); margin-bottom: 10px; }
.footer-brand img { width: 26px; height: 26px; border-radius: 6px; }
.footer-grid h4 { margin: 0 0 12px; color: var(--ink); font-size: .92rem; }
.footer-grid ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.footer-grid a:hover { color: var(--ink); }
.footer-bottom { margin-top: 40px; border-top: 1px solid var(--line-soft); padding-top: 20px; display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }

/* download page */
.page { padding: 72px 0 96px; }
.page-head { max-width: 720px; margin-bottom: 48px; }
.page-head h1 { margin: 0 0 14px; font-size: clamp(1.9rem, 4vw, 2.7rem); line-height: 1.15; letter-spacing: -.01em; font-weight: 900; }
.page-head p { margin: 0; color: var(--muted); font-size: 1.05rem; }

.dl-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 28px; align-items: start; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 32px; }
.card h2 { margin: 0 0 18px; font-size: 1.15rem; font-weight: 800; }
.version-rows { display: grid; gap: 0; }
.version-row { display: flex; justify-content: space-between; gap: 16px; padding: 13px 0; border-bottom: 1px solid var(--line-soft); font-size: .95rem; }
.version-row:last-of-type { border-bottom: none; }
.version-row dt { color: var(--muted); }
.version-row dd { margin: 0; text-align: right; font-weight: 700; }
.dl-actions { margin-top: 22px; display: grid; gap: 12px; }
.sha-box {
  display: flex;
  align-items: center;
  gap: 10px;
  background: #0E1112;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: .76rem;
  word-break: break-all;
  color: #C8CED3;
}
.copy-btn {
  flex: none;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
  font-size: .8rem;
  font-weight: 600;
}
.copy-btn:hover { border-color: var(--accent); }
.note-chip {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  color: var(--warn);
  font-size: .85rem;
  border: 1px solid rgba(230, 184, 75, .35);
  background: rgba(230, 184, 75, .08);
  border-radius: 10px;
  padding: 9px 12px;
}
.dl-error { color: var(--warn); font-size: .92rem; }

.step-list { display: grid; gap: 14px; margin: 0; padding: 0; list-style: none; }
.step-list li { display: flex; gap: 14px; }
.step-list .n {
  flex: none;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--accent);
  font-weight: 700;
}
.step-list b { display: block; font-weight: 700; }
.step-list span { color: var(--muted); font-size: .9rem; }

/* faq */
.faq { display: grid; gap: 12px; max-width: 780px; }
.faq details { background: var(--panel); border: 1px solid var(--line-soft); border-radius: var(--radius); padding: 18px 20px; }
.faq summary {
  cursor: pointer;
  font-weight: 700;
  font-size: 1rem;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--accent); font-weight: 700; font-size: 1.15rem; }
.faq details[open] summary::after { content: "−"; }
.faq .answer { margin: 12px 0 0; color: var(--muted); font-size: .94rem; }

/* reveal */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .5s ease, transform .5s ease; }
.reveal.in { opacity: 1; transform: none; }

/* responsive */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; gap: 44px; }
  .hero { min-height: auto; padding: 56px 0; }
  .steps { grid-template-columns: 1fr 1fr; }
  .trust-grid { grid-template-columns: 1fr 1fr; }
  .dl-grid { grid-template-columns: 1fr; }
}
@media (max-width: 680px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: var(--panel);
    border-bottom: 1px solid var(--line);
    padding: 12px 16px 16px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 13px 12px; font-size: 1rem; }
  .nav-links .btn { justify-content: center; }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .feature-grid, .scenario-list, .trust-grid, .steps { grid-template-columns: 1fr; }
  .cta-panel { padding: 36px 24px; }
  .footer-grid { grid-template-columns: 1fr; }
  .page { padding: 48px 0 72px; }
  .card { padding: 24px 20px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
  .reveal { opacity: 1; transform: none; }
}