:root{
  font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans JP",sans-serif;
  color:#151515;background:#fafafa;line-height:1.7
}
body{margin:0}
main{max-width:760px;margin:0 auto;padding:56px 24px 80px}
h1{font-size:2rem;line-height:1.25;margin:0 0 14px}
h2{font-size:1.25rem;margin-top:36px}
p,li{font-size:1rem}
.muted{color:#666}
.card{background:#fff;border:1px solid #e5e5e5;border-radius:14px;padding:22px;margin:24px 0}
nav{display:flex;gap:18px;flex-wrap:wrap;margin-top:28px}
a{color:#165dcc}
footer{margin-top:56px;padding-top:22px;border-top:1px solid #e5e5e5;color:#666;font-size:.9rem}
code{background:#f0f0f0;padding:2px 5px;border-radius:4px}