:root{
  --bg:#ffffff;
  --ink:#1a1a1a;
  --muted:#555;
  --line:#e5e5e9;
  --card:#fafafa;
  --accent:#ff6699;
}
*{box-sizing:border-box}
body{margin:0;font-family:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans JP","Hiragino Kaku Gothic ProN",Meiryo,sans-serif;color:var(--ink);background:var(--bg);line-height:1.8;letter-spacing:.02em}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:960px;margin:0 auto;padding:24px}
.header{display:flex;align-items:center;justify-content:space-between;padding:16px 24px;border-bottom:1px solid var(--line);position:sticky;top:0;background:rgba(255,255,255,.9);backdrop-filter:saturate(160%) blur(6px)}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);font-weight:700;text-decoration:none}
.brand svg{width:28px;height:28px}
.nav a{margin-left:16px;color:var(--muted)}
.hero{padding:56px 24px 24px}
.hero h1{font-size:clamp(1.8rem,3vw,2.4rem);margin:0 0 12px}
.hero p{margin:0;color:var(--muted)}
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin-top:24px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px;display:flex;flex-direction:column;justify-content:space-between}
.card h3{margin:0 0 8px;font-size:1.1rem}
.card p{margin:0;color:var(--muted);font-size:.95rem}
.prose h1,.prose h2{line-height:1.35}
.prose h2{margin-top:1.4em}
.footer{border-top:1px solid var(--line);padding:24px;color:var(--muted);font-size:.9rem}
@media (max-width:760px){.header{flex-direction:column;align-items:flex-start}}