:root{
  --bg:#fbfaf7;--surface:#ffffff;--ink:#1c2430;--muted:#556070;--line:#e3e0d8;
  --brand:#1f4e79;--brand-dark:#163a5a;--accent:#2e7d5b;--accent-bg:#e8f4ee;
  --warn-bg:#fff6e0;--warn-line:#e7c56a;--radius:10px;
}
*{box-sizing:border-box}
html{font-size:18px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:Georgia,"Times New Roman",serif;line-height:1.65}
a{color:var(--brand)}
a:hover{color:var(--brand-dark)}
img{max-width:100%}
.wrap{max-width:860px;margin:0 auto;padding:0 18px}
header.site{background:var(--brand);color:#fff}
header.site .wrap{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px 20px;padding-top:14px;padding-bottom:14px}
.logo{color:#fff;text-decoration:none;font-weight:bold;font-size:1.15rem;font-family:Arial,Helvetica,sans-serif;letter-spacing:.2px}
.logo span{color:#bfe3cf}
nav.main{display:flex;flex-wrap:wrap;gap:4px 16px;font-family:Arial,Helvetica,sans-serif;font-size:.85rem}
nav.main a{color:#fff;text-decoration:none;opacity:.92}
nav.main a:hover{opacity:1;text-decoration:underline;color:#fff}
.crumbs{font-family:Arial,Helvetica,sans-serif;font-size:.8rem;color:var(--muted);margin:18px 0 0}
.crumbs a{color:var(--muted)}
main{padding:10px 0 40px}
h1{font-family:Arial,Helvetica,sans-serif;font-size:2rem;line-height:1.2;margin:14px 0 8px;color:var(--brand-dark)}
h2{font-family:Arial,Helvetica,sans-serif;font-size:1.4rem;line-height:1.3;margin:36px 0 10px;color:var(--brand-dark)}
h3{font-family:Arial,Helvetica,sans-serif;font-size:1.1rem;margin:24px 0 6px}
.updated{font-family:Arial,Helvetica,sans-serif;font-size:.8rem;color:var(--muted);margin:0 0 18px}
.lead{font-size:1.1rem}
.answer{background:var(--accent-bg);border-left:5px solid var(--accent);padding:14px 18px;border-radius:0 var(--radius) var(--radius) 0;margin:18px 0}
.answer p{margin:.3em 0}
.note{background:var(--warn-bg);border:1px solid var(--warn-line);padding:12px 16px;border-radius:var(--radius);font-size:.92rem;margin:18px 0}
table{border-collapse:collapse;width:100%;margin:14px 0;font-family:Arial,Helvetica,sans-serif;font-size:.9rem;background:var(--surface)}
th,td{border:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
th{background:#eef2f6}
td.num,th.num{text-align:right;font-variant-numeric:tabular-nums}
.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch}
.calc{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px;margin:20px 0;box-shadow:0 1px 3px rgba(0,0,0,.04)}
.calc h2{margin-top:0}
.field{margin:0 0 14px}
.field label{display:block;font-family:Arial,Helvetica,sans-serif;font-weight:bold;font-size:.9rem;margin:0 0 4px}
.field .hint{display:block;font-family:Arial,Helvetica,sans-serif;font-size:.78rem;color:var(--muted);margin-top:3px}
.field input,.field select{width:100%;max-width:360px;font-size:1rem;padding:10px 12px;border:1px solid #b9bfc8;border-radius:8px;background:#fff;color:var(--ink)}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:0 20px}
@media (max-width:640px){.grid2{grid-template-columns:1fr}h1{font-size:1.6rem}}
button.go{font-family:Arial,Helvetica,sans-serif;font-size:1rem;font-weight:bold;background:var(--accent);color:#fff;border:0;border-radius:8px;padding:12px 26px;cursor:pointer}
button.go:hover{background:#256849}
.result{margin-top:18px}
.result .big{font-family:Arial,Helvetica,sans-serif;font-size:2rem;font-weight:bold;color:var(--accent)}
.result .err{color:#a33;font-family:Arial,Helvetica,sans-serif}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;margin:18px 0}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px}
.card h3{margin:0 0 6px}
.card p{margin:0;font-size:.92rem;color:var(--muted)}
.related{border-top:1px solid var(--line);margin-top:40px;padding-top:10px}
.related ul{padding-left:20px}
details{background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:10px 14px;margin:8px 0}
summary{cursor:pointer;font-family:Arial,Helvetica,sans-serif;font-weight:bold}
footer.site{background:#20262f;color:#c9ced6;font-family:Arial,Helvetica,sans-serif;font-size:.8rem;padding:24px 0}
footer.site a{color:#e3e7ec}
footer.site p{margin:.4em 0}