:root{--ink:#1d2327;--muted:#5d676d;--line:#dfe3e1;--paper:#fbfaf6;--accent:#2f7d6b}
@media (prefers-color-scheme:dark){:root{--ink:#eef1ef;--muted:#a3adb0;--line:#343c40;--paper:#171b1d;--accent:#6fcfb6}}
*{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.75 -apple-system,BlinkMacSystemFont,"Hiragino Sans","Noto Sans JP","Segoe UI",sans-serif}
main{max-width:720px;margin:0 auto;padding:40px 20px 80px}
header{display:flex;flex-wrap:wrap;gap:8px 20px;align-items:baseline;border-bottom:1px solid var(--line);padding-bottom:16px;margin-bottom:32px}
header strong{font-size:20px}
nav{display:flex;flex-wrap:wrap;gap:4px 16px}
a{color:var(--accent)}
h1{font-size:28px;line-height:1.3;margin:0 0 8px}
h2{font-size:19px;margin:36px 0 8px}
p,ul{margin:0 0 14px}
.meta{color:var(--muted);font-size:14px}
section[lang]{padding-top:8px}
section[lang]+section[lang]{border-top:1px solid var(--line);margin-top:48px;padding-top:40px}
footer{border-top:1px solid var(--line);margin-top:56px;padding-top:16px;color:var(--muted);font-size:14px}