:root{--ink:#172033;--sub:#64748b;--red:#df382f;--line:#dbe3ec}
*{box-sizing:border-box}body{margin:0;background:#f1f4f7;color:var(--ink);font-family:system-ui,-apple-system,"Segoe UI","Noto Sans JP",sans-serif;line-height:1.8}
header{background:#202020;color:#fff;padding:18px 5vw}.brand{color:#fff;text-decoration:none;font-weight:900;letter-spacing:.12em}.tag{display:block;color:#aeb3ba;font-size:12px;letter-spacing:0;margin-top:3px}
main{max-width:900px;margin:28px auto;padding:0 18px}.paper{background:#fff;border-radius:16px;padding:30px;box-shadow:0 3px 15px #0f172a12;border-top:3px solid #2767f4}h1{font-size:28px;margin:0 0 22px}h2{font-size:20px;margin:28px 0 8px;padding-bottom:5px;border-bottom:1px solid var(--line)}p,li{font-size:15px}.muted{color:var(--sub);font-size:13px}.notice{background:#fffbeb;color:#92400e;border-radius:10px;padding:12px 15px}.contact{display:inline-block;background:var(--red);color:#fff;text-decoration:none;border-radius:10px;padding:11px 18px;font-weight:800}.back{display:inline-block;margin-bottom:14px;color:#075985}
footer{max-width:900px;margin:0 auto;padding:0 18px 30px;color:var(--sub);font-size:12px}footer nav{display:flex;gap:14px;flex-wrap:wrap;margin:7px 0}footer a{color:#475569}.pr{color:#92400e;font-weight:800}
.settings-note{border-left:4px solid #2767f4;background:#eff6ff;padding:12px 14px}.settings-note button{margin-top:8px}
@media(max-width:600px){main{margin:16px auto;padding:0 10px}.paper{padding:21px 16px}h1{font-size:24px}h2{font-size:18px}footer{padding:0 14px 24px}}