:root { --ink:#1f2328; --muted:#57606a; --line:#d0d7de; --accent:#0f766e; --bg:#ffffff; --soft:#f6f8fa; }
* { box-sizing: border-box; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Yu Gothic", sans-serif; color: var(--ink); background: var(--bg); line-height: 1.75; }
header { border-bottom: 1px solid var(--line); background: var(--soft); }
.wrap { max-width: 820px; margin: 0 auto; padding: 0 16px; }
header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-top: 14px; padding-bottom: 14px; flex-wrap: wrap; }
.brand { font-weight: 800; font-size: 18px; color: var(--ink); text-decoration: none; }
nav a { color: var(--accent); text-decoration: none; margin-left: 16px; font-size: 15px; }
nav a:first-child { margin-left: 0; }
main { padding: 28px 0 40px; }
h1 { font-size: 26px; line-height: 1.4; margin: 0 0 6px; }
h2 { font-size: 19px; margin: 28px 0 6px; padding-top: 6px; border-top: 1px solid var(--line); }
p, li { font-size: 15.5px; overflow-wrap: anywhere; }
.meta { color: var(--muted); font-size: 14px; margin: 0 0 18px; }
.lang { margin: 40px 0 0; padding-top: 24px; border-top: 3px solid var(--line); }
a { color: var(--accent); word-break: break-all; }
.card { border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; background: var(--soft); margin: 16px 0; }
footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 13.5px; padding: 18px 0 28px; }
footer a { margin-right: 14px; }