:root {
  --bg: #f7f5f0;
  --bg-elev: #ffffff;
  --ink: #14201a;
  --ink-soft: #3d4a43;
  --line: #d7ddd8;
  --accent: #1f6b4a;
  --accent-soft: #e6f2ec;
  --warn: #6b5a1f;
  --max: 42rem;
  --serif: Georgia, "Times New Roman", "Songti SC", "Noto Serif SC", serif;
  --sans: "Inter", "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Noto Sans SC", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
  font-size: 1.05rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 0.15em; }
a:hover { color: #145239; }

.wrap { width: min(100% - 2rem, 52rem); margin-inline: auto; }

.site-header {
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: blur(10px);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.9rem 0; gap: 1rem;
}
.brand {
  display: inline-flex; align-items: center; gap: 0.55rem;
  color: inherit; text-decoration: none; font-family: var(--serif);
  font-size: 1.35rem; font-weight: 600; letter-spacing: -0.02em;
}
.brand-mark {
  width: 1.55rem; height: 1.55rem; border-radius: 0.4rem;
  background: #0B1F17; color: #E8F2EC;
  display: grid; place-items: center;
  font-family: var(--serif); font-size: 0.95rem; font-weight: 600;
}
.lang-toggle {
  display: inline-flex; border: 1px solid var(--line); border-radius: 999px;
  overflow: hidden; background: var(--bg-elev);
}
.lang-toggle button {
  appearance: none; border: 0; background: transparent;
  padding: 0.35rem 0.75rem; font: inherit; font-size: 0.85rem;
  color: var(--ink-soft); cursor: pointer;
}
.lang-toggle button[aria-pressed="true"] {
  background: var(--accent); color: #fff;
}

.hero {
  padding: 4.5rem 0 3rem;
}
.eyebrow {
  display: inline-block; margin-bottom: 1rem;
  padding: 0.25rem 0.65rem; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent);
  font-size: 0.82rem; font-weight: 600; letter-spacing: 0.02em;
}
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.15; letter-spacing: -0.025em;
  margin: 0 0 1.25rem; font-weight: 600; max-width: 18ch;
}
.lede {
  max-width: var(--max); color: var(--ink-soft); margin: 0 0 1.75rem;
  font-size: 1.08rem;
}
.cta {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: var(--accent); color: #fff !important; text-decoration: none;
  padding: 0.75rem 1.15rem; border-radius: 999px; font-weight: 600;
  font-size: 0.98rem;
}
.cta:hover { background: #145239; }

section.block {
  padding: 2.75rem 0;
  border-top: 1px solid var(--line);
}
section.block h2 {
  font-family: var(--serif);
  font-size: clamp(1.45rem, 3vw, 1.85rem);
  line-height: 1.25; margin: 0 0 1rem; letter-spacing: -0.02em;
  max-width: 22ch;
}
section.block p, section.block li {
  color: var(--ink-soft); max-width: var(--max);
}
section.block p { margin: 0 0 1rem; }
section.block p:last-child { margin-bottom: 0; }

.steps {
  list-style: none; padding: 0; margin: 1.25rem 0 0;
  display: grid; gap: 0.85rem;
}
.steps li {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: 0.9rem; padding: 1rem 1.1rem; max-width: none;
}
.steps strong { color: var(--ink); display: block; margin-bottom: 0.2rem; }

.roadmap {
  list-style: none; padding: 0; margin: 1rem 0 0; display: grid; gap: 0.85rem;
}
.roadmap li {
  max-width: none; background: var(--bg-elev);
  border-left: 3px solid var(--accent);
  padding: 0.85rem 1rem; border-radius: 0 0.7rem 0.7rem 0;
}
.roadmap strong { color: var(--ink); }

.note {
  margin-top: 1rem; font-size: 0.92rem; color: var(--warn);
}
.cite {
  margin-top: 0.85rem; font-size: 0.88rem; color: var(--ink-soft);
}
.cite a { word-break: break-all; }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 2.5rem 0 3rem;
  color: var(--ink-soft); font-size: 0.92rem;
}
.site-footer p { margin: 0 0 0.55rem; max-width: 40rem; }
.site-footer .note {
  margin-top: 1rem; padding-top: 0.85rem; border-top: 1px dashed var(--line);
  font-size: 0.85rem;
}

/* Language visibility */
[data-lang="en"] [lang-zh],
html[data-lang="zh"] [lang-en] { display: none !important; }
html[data-lang="zh"] [lang-zh] { display: contents; }
html[data-lang="en"] [lang-en] { display: contents; }

/* For block-level bilingual pairs we use sibling containers */
.lang-block { display: none; }
html[data-lang="en"] .lang-block.en,
html[data-lang="zh"] .lang-block.zh { display: block; }

@media (max-width: 640px) {
  .hero { padding: 3rem 0 2.25rem; }
  .hero h1 { max-width: none; }
  section.block { padding: 2.1rem 0; }
}