:root {
  --ink: #171717;
  --text: #2b2f36;
  --muted: #64707f;
  --line: #dfe4ea;
  --panel: #ffffff;
  --paper: #f7f8fa;
  --wash: #eef3f1;
  --teal: #0b7a75;
  --teal-dark: #075e5a;
  --red: #b23a2b;
  --blue: #315f91;
  --gold: #9a6a12;
  --shadow: 0 22px 70px rgba(23, 23, 23, .08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--text);
  background: var(--paper);
  font-family: "IBM Plex Sans", "Microsoft YaHei", "PingFang SC", sans-serif;
  line-height: 1.65;
}

a {
  color: var(--teal-dark);
  font-weight: 700;
  text-decoration: none;
}

a:hover { text-decoration: underline; }

.site-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 72px;
  padding: 0 clamp(20px, 5vw, 72px);
  background: rgba(247, 248, 250, .86);
  border-bottom: 1px solid rgba(223, 228, 234, .8);
  backdrop-filter: blur(18px);
}

.site-nav.compact { position: relative; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  letter-spacing: .01em;
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 2px solid var(--ink);
  color: var(--ink);
  font-size: 12px;
  font-weight: 800;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 26px);
  font-size: 14px;
}

.nav-links a { color: #343a43; }

.hero {
  position: relative;
  min-height: calc(100vh - 72px);
  overflow: hidden;
  display: grid;
  align-items: center;
  padding: 76px clamp(20px, 5vw, 72px) 54px;
  background:
    linear-gradient(90deg, rgba(247,248,250,.98) 0%, rgba(247,248,250,.94) 44%, rgba(247,248,250,.62) 100%),
    radial-gradient(circle at 78% 20%, rgba(11,122,117,.16), transparent 34%),
    linear-gradient(135deg, #f7f8fa, #edf2f3);
}

.hero::before {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 18px;
  background: linear-gradient(90deg, var(--teal), var(--red), var(--gold));
}

.hero-art {
  position: absolute;
  right: -5vw;
  top: 12vh;
  width: min(760px, 54vw);
  opacity: .28;
  transform: rotate(-2deg);
  filter: saturate(.75);
}

.hero-art img { width: 100%; }

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(980px, 100%);
}

.kicker,
.section-label {
  margin: 0 0 16px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
}

h1,
h2 {
  margin: 0;
  color: var(--ink);
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-weight: 900;
  letter-spacing: 0;
}

h1 {
  max-width: 960px;
  font-size: clamp(46px, 7vw, 88px);
  line-height: 1.04;
}

h2 {
  font-size: clamp(32px, 5vw, 58px);
  line-height: 1.08;
}

h3 {
  margin: 12px 0 10px;
  color: var(--ink);
  font-size: 22px;
  line-height: 1.22;
  letter-spacing: 0;
}

.nowrap { white-space: nowrap; }

.hero-copy,
.section-copy {
  max-width: 720px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 20px;
}

.hero-actions,
.inline-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 11px 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  box-shadow: 0 8px 22px rgba(23, 23, 23, .05);
}

.button.primary {
  border-color: var(--teal);
  background: var(--teal);
  color: #fff;
}

.button.ghost {
  border-color: rgba(23,23,23,.18);
  background: transparent;
  box-shadow: none;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(120px, 1fr));
  gap: 1px;
  width: min(760px, 100%);
  margin-top: 56px;
  border: 1px solid var(--line);
  background: var(--line);
  box-shadow: var(--shadow);
}

.metric-strip div {
  padding: 18px;
  background: rgba(255,255,255,.9);
}

.metric-strip strong {
  display: block;
  color: var(--ink);
  font-size: 30px;
  line-height: 1;
}

.metric-strip span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
}

.section {
  padding: clamp(64px, 9vw, 112px) clamp(20px, 5vw, 72px);
}

.muted { background: #eef3f1; }

.intro-grid,
.split {
  display: grid;
  grid-template-columns: minmax(0, .82fr) minmax(340px, 1fr);
  gap: clamp(30px, 6vw, 80px);
  align-items: start;
}

.steps {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.steps li {
  min-height: 184px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 12px 34px rgba(23, 23, 23, .05);
}

.steps span {
  color: var(--red);
  font-size: 12px;
  font-weight: 800;
}

.steps strong {
  display: block;
  margin-top: 14px;
  color: var(--ink);
  font-size: 20px;
}

.steps p,
.roadmap-card p {
  margin: 8px 0 0;
  color: var(--muted);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 30px;
}

.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.roadmap-card {
  display: grid;
  grid-template-columns: 44% 1fr;
  gap: 20px;
  align-items: center;
  min-height: 300px;
  padding: 18px;
  border: 1px solid rgba(23, 23, 23, .1);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 12px 40px rgba(23, 23, 23, .06);
}

.roadmap-card img {
  width: 100%;
  height: 230px;
  object-fit: contain;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f9fafb;
}

.pill {
  display: inline-flex;
  align-items: center;
  height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(11,122,117,.12);
  color: var(--teal-dark);
  font-size: 12px;
  font-weight: 800;
}

.pill.red { background: rgba(178,58,43,.12); color: var(--red); }
.pill.blue { background: rgba(49,95,145,.12); color: var(--blue); }
.pill.gold { background: rgba(154,106,18,.14); color: var(--gold); }

.directory-panel {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #151718;
  color: #eef3f1;
  box-shadow: var(--shadow);
}

.directory-panel h3 {
  margin: 0 0 12px;
  color: #fff;
}

pre {
  margin: 0;
  overflow: auto;
  color: #d7e5e1;
  font-size: 15px;
  line-height: 1.6;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 36px clamp(20px, 5vw, 72px);
  color: var(--muted);
  background: #fff;
  border-top: 1px solid var(--line);
}

.site-footer p { margin: 4px 0 0; }

.page-hero {
  padding: 74px clamp(20px, 5vw, 72px) 52px;
  background:
    linear-gradient(135deg, rgba(11,122,117,.12), transparent 44%),
    #fff;
  border-bottom: 1px solid var(--line);
}

.page-hero h1 {
  font-size: clamp(46px, 7vw, 92px);
}

.page-hero p:not(.kicker) {
  max-width: 780px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 20px;
}

.download-main {
  padding: 34px clamp(20px, 5vw, 72px) 80px;
}

.download-summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-bottom: 34px;
  border: 1px solid var(--line);
  background: var(--line);
}

.download-summary div {
  padding: 22px;
  background: #fff;
}

.download-summary strong {
  display: block;
  color: var(--ink);
  font-size: 28px;
}

.download-summary span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.paper-section {
  margin-top: 28px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 10px 32px rgba(23,23,23,.045);
}

.paper-section h2 {
  margin-bottom: 18px;
  font-size: 30px;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.paper-table {
  width: 100%;
  min-width: 760px;
  border-collapse: collapse;
}

.paper-table th,
.paper-table td {
  padding: 13px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.paper-table th {
  background: #f1f4f6;
  color: var(--ink);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: .05em;
}

.paper-table tr:last-child td { border-bottom: 0; }
.paper-table td:nth-child(2) { white-space: nowrap; color: var(--muted); }
.paper-table td:nth-child(3),
.paper-table td:nth-child(4) { white-space: nowrap; }

@media (max-width: 980px) {
  .hero-art { width: 74vw; right: -18vw; opacity: .18; }
  .intro-grid,
  .split,
  .roadmap-card {
    grid-template-columns: 1fr;
  }
  .roadmap-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .site-nav {
    position: relative;
    align-items: flex-start;
    flex-direction: column;
    padding-top: 14px;
    padding-bottom: 14px;
  }
  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }
  h1 { font-size: clamp(38px, 11.5vw, 54px); }
  .nowrap { white-space: normal; }
  .hero-art { display: none; }
  .hero { min-height: auto; padding-top: 54px; }
  .metric-strip,
  .steps,
  .download-summary {
    grid-template-columns: 1fr;
  }
  .roadmap-card img { height: 190px; }
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}