:root {
  --bg: #fbfbfa;
  --fg: #17171a;
  --muted: #6b6b74;
  --line: #e4e4e1;
  --card: #ffffff;
  --accent: #3b5bdb;
  --radius: 14px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #101013;
    --fg: #ececef;
    --muted: #9a9aa4;
    --line: #26262c;
    --card: #17171b;
    --accent: #8ea3ff;
  }
}
:root[data-theme="dark"] {
  --bg: #101013;
  --fg: #ececef;
  --muted: #9a9aa4;
  --line: #26262c;
  --card: #17171b;
  --accent: #8ea3ff;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 ui-sans-serif, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  letter-spacing: -0.01em;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

header.site {
  display: flex; align-items: center; gap: 24px;
  max-width: 1080px; margin: 0 auto; padding: 22px 24px;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--fg); font-weight: 620; }
.brand .thin { font-weight: 400; color: var(--muted); }
.mark {
  width: 20px; height: 20px; border-radius: 6px; display: inline-block;
  background: linear-gradient(135deg, #6b8cff, #b06bff 55%, #ff8f6b);
}
header nav { display: flex; gap: 20px; margin-left: auto; font-size: 15px; }
header nav a { color: var(--muted); }
header nav a.active { color: var(--fg); }
.theme {
  background: none; border: 1px solid var(--line); color: var(--muted);
  border-radius: 8px; width: 32px; height: 32px; cursor: pointer; font-size: 14px;
}

main { max-width: 1080px; margin: 0 auto; padding: 40px 24px 72px; }

.hero h1 { font-size: clamp(28px, 4vw, 42px); line-height: 1.15; margin: 0 0 14px; letter-spacing: -0.03em; }
.hero p { max-width: 62ch; color: var(--muted); margin: 0 0 20px; font-size: 17px; }
.meta { display: flex; flex-wrap: wrap; gap: 22px; font-size: 14px; color: var(--muted); margin-bottom: 44px; }
.meta b { color: var(--fg); }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.grid figure { margin: 0; }
.grid img {
  width: 100%; aspect-ratio: 3 / 2; object-fit: cover; display: block;
  border-radius: var(--radius); border: 1px solid var(--line); background: var(--card);
}
.grid figcaption {
  display: flex; justify-content: space-between; font-size: 14px;
  padding: 10px 2px 0; color: var(--fg);
}
.grid figcaption span { color: var(--muted); }

.note {
  margin-top: 56px; padding: 26px; border: 1px solid var(--line);
  border-radius: var(--radius); background: var(--card);
}
.note h2 { margin: 0 0 8px; font-size: 19px; letter-spacing: -0.02em; }
.note p { color: var(--muted); margin: 0 0 14px; max-width: 60ch; }
.btn {
  display: inline-block; padding: 9px 16px; border-radius: 9px;
  background: var(--accent); color: #fff; font-size: 15px; font-weight: 520;
}
.btn:hover { text-decoration: none; opacity: .9; }

.prose { max-width: 68ch; }
.prose h1 { font-size: clamp(26px, 3.4vw, 34px); letter-spacing: -0.03em; margin: 0 0 18px; }
.prose h2 { font-size: 19px; letter-spacing: -0.02em; margin: 34px 0 8px; }
.prose p, .prose li { color: var(--muted); }
.prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 13.5px;
  background: var(--card); border: 1px solid var(--line); border-radius: 5px; padding: 1px 5px;
}

footer {
  border-top: 1px solid var(--line); color: var(--muted);
  font-size: 14px; padding: 22px 24px;
}
footer p { max-width: 1080px; margin: 0 auto; }

@media (max-width: 620px) {
  header.site { flex-wrap: wrap; gap: 14px; }
  header nav { margin-left: 0; order: 3; width: 100%; }
}