:root {
  --bg: #fbfbf9;
  --bg-soft: #f2f2ee;
  --fg: #1c1c1a;
  --fg-soft: #5c5c56;
  --line: #e2e2dc;
  --accent: #0f766e;
  --accent-soft: #d9efec;
  --radius: 14px;
  --max: 760px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #131413;
    --bg-soft: #1c1e1c;
    --fg: #ecece7;
    --fg-soft: #a3a39b;
    --line: #2c2f2d;
    --accent: #5eead4;
    --accent-soft: #14332f;
  }
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover { text-decoration: underline; }

.wrap {
  width: min(100% - 40px, var(--max));
  margin-inline: auto;
}

.site-header {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 64px;
}

.brand {
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--fg);
  font-size: 15px;
}

.brand span { color: var(--accent); }

.nav {
  display: flex;
  gap: 22px;
  font-size: 14px;
}

.nav a {
  color: var(--fg-soft);
}

.nav a:hover,
.nav a[aria-current="page"] {
  color: var(--fg);
  text-decoration: none;
}

.hero {
  padding: 88px 0 56px;
}

.eyebrow {
  color: var(--accent);
  font-size: 13px;
  letter-spacing: .14em;
  text-transform: uppercase;
  font-weight: 600;
  margin: 0 0 18px;
}

.hero h1 {
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1.22;
  letter-spacing: -.02em;
  margin: 0 0 20px;
  font-weight: 700;
}

.hero p {
  color: var(--fg-soft);
  font-size: 18px;
  max-width: 56ch;
  margin: 0;
}

.hero .meta {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--fg-soft);
  background: var(--bg-soft);
  border: 1px solid var(--line);
  padding: 3px 10px;
  border-radius: 999px;
}

.section {
  padding: 40px 0 72px;
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  border-top: 1px solid var(--line);
  padding-top: 22px;
  margin-bottom: 26px;
}

.section-head h2 {
  font-size: 15px;
  letter-spacing: .12em;
  text-transform: uppercase;
  margin: 0;
  color: var(--fg-soft);
  font-weight: 600;
}

.section-head a { font-size: 14px; }

.cards {
  display: grid;
  gap: 14px;
}

.card {
  display: block;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: inherit;
  transition: border-color .18s ease, transform .18s ease;
  background: var(--bg);
}

.card:hover {
  border-color: var(--accent);
  text-decoration: none;
  transform: translateY(-1px);
}

.card time {
  font-size: 12px;
  color: var(--fg-soft);
  letter-spacing: .04em;
}

.card h3 {
  margin: 8px 0 6px;
  font-size: 20px;
  line-height: 1.4;
  letter-spacing: -.01em;
}

.card p {
  margin: 0;
  color: var(--fg-soft);
  font-size: 15px;
}

.article {
  padding: 64px 0 88px;
}

.article-header {
  margin-bottom: 40px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.article-header h1 {
  font-size: clamp(28px, 5vw, 40px);
  line-height: 1.3;
  letter-spacing: -.02em;
  margin: 10px 0 14px;
}

.article-header .lede {
  color: var(--fg-soft);
  font-size: 18px;
  margin: 0;
}

.article-body h2 {
  font-size: 24px;
  margin: 44px 0 14px;
  letter-spacing: -.01em;
}

.article-body h3 {
  font-size: 19px;
  margin: 30px 0 10px;
}

.article-body p { margin: 0 0 18px; }

.article-body ul,
.article-body ol { margin: 0 0 18px; padding-left: 1.3em; }

.article-body li { margin-bottom: 6px; }

.article-body code {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: .1em .36em;
  font-size: .88em;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.article-body pre {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 18px;
  overflow-x: auto;
  margin: 0 0 20px;
}

.article-body pre code {
  background: none;
  border: 0;
  padding: 0;
  font-size: 13.5px;
  line-height: 1.65;
}

blockquote {
  margin: 0 0 20px;
  padding: 2px 0 2px 18px;
  border-left: 3px solid var(--accent);
  color: var(--fg-soft);
}

.back {
  display: inline-block;
  margin-bottom: 26px;
  font-size: 14px;
}

.note-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.note-list li {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.note-list li:first-child { border-top: 1px solid var(--line); }

.note-list a {
  font-size: 19px;
  color: var(--fg);
  font-weight: 600;
}

.note-list a:hover { color: var(--accent); }

.note-list p {
  margin: 6px 0 0;
  color: var(--fg-soft);
  font-size: 15px;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 30px 0 44px;
  color: var(--fg-soft);
  font-size: 13px;
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
}

@media (max-width: 600px) {
  body { font-size: 16px; }
  .hero { padding: 60px 0 36px; }
  .nav { gap: 16px; }
  .card { padding: 18px; }
}