:root { --fg:#222; --muted:#666; --accent:#2b9cd8; --bg:#fafafa; --card:#fff; }
*{box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Noto Sans JP",sans-serif;margin:0;color:var(--fg);background:var(--bg);line-height:1.8}
header{padding:2rem 1.25rem 1rem;background:#fff;border-bottom:1px solid #eee}
header nav{max-width:720px;margin:0 auto;display:flex;gap:1.5rem;align-items:center}
header nav .brand{font-weight:700;font-size:1.1rem;color:var(--fg);text-decoration:none}
header nav a.link{color:var(--accent);text-decoration:none;font-size:.9rem}
header nav a.link:hover{text-decoration:underline}
main{max-width:720px;margin:0 auto;padding:2rem 1.25rem 3rem}
main h1{font-size:1.7rem;margin:0 0 .5rem}
main .updated{color:var(--muted);font-size:.85rem;margin:0 0 2rem}
main h2{font-size:1.2rem;margin:2rem 0 .75rem;padding-top:.5rem;border-top:1px solid #eee}
main h3{font-size:1rem;margin:1.25rem 0 .5rem}
main p, main li{font-size:.95rem}
main ul{padding-left:1.25rem}
main a{color:var(--accent);text-decoration:none}
main a:hover{text-decoration:underline}
footer{text-align:center;padding:2rem 1rem;color:var(--muted);font-size:.85rem;border-top:1px solid #eee;background:#fff}