:root{--brand:#8a4a3c;--ink:#2a211e;--muted:#6b5d57;--bg:#f7f3f1;--line:#e7ddd8}
*{box-sizing:border-box}body{margin:0;font:17px/1.7 -apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;color:var(--ink);background:#fff}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
header.site{display:flex;flex-wrap:wrap;gap:.5rem 1.25rem;align-items:center;justify-content:space-between;padding:.9rem 1.25rem;border-bottom:1px solid var(--line);position:sticky;top:0;background:#fff;z-index:5}
header .logo{font-weight:800;font-size:1.15rem;color:var(--ink);display:inline-flex;align-items:center;gap:.5rem}
header .logo .mark{display:inline-flex;width:30px;height:30px;border-radius:7px;background:var(--brand);align-items:center;justify-content:center}
header nav a{margin-left:0;color:var(--muted);font-size:.93rem}
main{max-width:820px;margin:0 auto;padding:1.5rem 1.25rem 3rem}
h1{font-size:2rem;line-height:1.25;margin:.4em 0 .5em}
h2{font-size:1.4rem;margin:1.6em 0 .5em;padding-top:.2em}
h3{font-size:1.13rem;margin:1.3em 0 .4em}
p{margin:.7em 0}ul{margin:.7em 0;padding-left:1.3em}li{margin:.3em 0}
.calc{background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:1.25rem 1.25rem 1.4rem;margin:1.6rem 0}
.calc h2{margin:.1em 0 .3em}.calc-note{color:var(--muted);font-size:.92rem;margin:.2em 0 1em}
.calc label{display:block;font-weight:600;font-size:.92rem;margin:.7rem 0 .1rem}
.calc input[type=number],.calc select{width:100%;padding:.6rem;border:1px solid var(--line);border-radius:8px;font:inherit;margin-top:.25rem}
.calc label.chk{display:flex;align-items:center;gap:.5rem;font-weight:500;margin-top:.9rem}
.calc label.chk input{width:auto}
.calc button{margin-top:1rem;background:var(--brand);color:#fff;border:0;border-radius:9px;padding:.75rem 1.3rem;font:600 1rem inherit;cursor:pointer}
.calc-out{margin-top:1rem;padding:1rem;background:#fff;border:1px solid var(--line);border-radius:10px}
.calc-out strong{display:block;font-size:1.3rem;color:var(--brand)}.calc-out span{display:block;color:var(--muted);font-size:.9rem;margin-top:.35rem}
.guidehub,.related{max-width:820px;margin:2rem auto 0;padding:1.4rem 1.25rem;border-top:1px solid var(--line)}
.guidehub h3{font-size:1rem;color:var(--muted);text-transform:uppercase;letter-spacing:.03em;margin:1.1em 0 .3em}
.guidehub ul,.related ul{list-style:none;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:.35rem 1.25rem}
@media(max-width:600px){.guidehub ul,.related ul{grid-template-columns:1fr}}
footer.site{border-top:1px solid var(--line);background:var(--bg);padding:1.5rem 1.25rem;color:var(--muted);font-size:.86rem}
footer.site .disc{max-width:820px;margin:0 auto .7rem}footer .by{max-width:820px;margin:0 auto .5rem}
footer.site nav{max-width:820px;margin:0 auto;display:flex;gap:1rem;flex-wrap:wrap}