:root{
  --bg:#fafbfc; --card:#ffffff; --ink:#1a2332; --muted:#5b6b7f;
  --line:#e4e9f0; --accent:#0f6cbd; --accent-dark:#0a4f8a; --good:#18794e;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  line-height:1.65;font-size:17px}
.wrap{max-width:860px;margin:0 auto;padding:0 20px}
.site-header{background:#0d1b2a;color:#fff;padding:14px 0;position:sticky;top:0;z-index:10}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between}
.brand{color:#fff;font-weight:800;font-size:1.25rem;text-decoration:none;letter-spacing:.3px}
.site-header nav a{color:#cfe0f2;text-decoration:none;margin-left:18px;font-size:.95rem}
.site-header nav a:hover{color:#fff}
main{padding:28px 0 40px}
h1{font-size:1.9rem;line-height:1.25;margin:.4em 0}
h2{font-size:1.35rem;margin-top:2em;border-bottom:2px solid var(--line);padding-bottom:.3em}
h3{font-size:1.1rem}
.lede{color:var(--muted);font-size:1.08rem}
a{color:var(--accent)}
.hero{background:linear-gradient(135deg,#0d1b2a,#14467a);color:#fff;border-radius:14px;
  padding:34px 30px;margin-bottom:30px}
.hero h1{margin-top:0;font-size:2rem}
.hero p{color:#d7e5f5;max-width:60ch}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px;margin-top:14px}
.card{background:var(--card);border:1px solid var(--line);border-radius:10px;
  padding:16px;text-decoration:none;color:var(--ink);transition:box-shadow .15s}
.card:hover{box-shadow:0 4px 18px rgba(15,108,189,.14)}
.card h3{margin:.2em 0;color:var(--accent-dark)}
.card p{margin:.3em 0 0;color:var(--muted);font-size:.93rem}
.calculator{background:var(--card);border:1px solid var(--line);border-radius:12px;
  padding:22px;margin:22px 0;box-shadow:0 2px 10px rgba(0,0,0,.04)}
.calc-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:14px}
.field label{display:block;font-weight:600;font-size:.92rem;margin-bottom:5px}
.field input,.field select{width:100%;padding:10px 12px;font-size:1rem;
  border:1px solid var(--line);border-radius:8px;background:#fff}
.field input:focus,.field select:focus{outline:2px solid var(--accent);border-color:var(--accent)}
.btn{display:inline-block;background:var(--accent);color:#fff;border:none;border-radius:8px;
  padding:12px 26px;font-size:1.02rem;font-weight:700;cursor:pointer;margin-top:14px}
.btn:hover{background:var(--accent-dark)}
.results{margin-top:20px;border-top:1px solid var(--line);padding-top:16px;display:none}
.results.show{display:block}
.result-hero{background:#eef7f0;border:1px solid #bfe3cd;border-radius:10px;
  padding:16px 18px;margin-bottom:14px}
.result-hero .big{font-size:2rem;font-weight:800;color:var(--good)}
.result-hero .lbl{color:var(--muted);font-size:.92rem}
table.brk{width:100%;border-collapse:collapse;margin:12px 0;font-size:.95rem}
table.brk th,table.brk td{border:1px solid var(--line);padding:8px 10px;text-align:right}
table.brk th{background:#f1f5f9;text-align:right}
table.brk td:first-child,table.brk th:first-child{text-align:left}
details{border:1px solid var(--line);border-radius:8px;margin:10px 0;background:#fff}
summary{padding:12px 16px;cursor:pointer;font-weight:600}
details p{padding:0 16px 14px;margin:0;color:#33414f}
.related ul{columns:2;list-style:none;padding:0}
.related li{margin:6px 0;break-inside:avoid}
.disclaimer{background:#fff8e6;border:1px solid #f0d998;border-radius:8px;
  padding:12px 16px;font-size:.88rem;color:#6b5a2e;margin-top:26px}
.site-footer{background:#0d1b2a;color:#9fb3c8;padding:30px 0;margin-top:20px;font-size:.9rem}
.site-footer a{color:#cfe0f2}
.site-footer .disclaimer{background:none;border:none;padding:0;color:#8fa3b8}
.why ul{padding-left:20px}
.prose table{width:100%;border-collapse:collapse;margin:14px 0;font-size:.95rem}
.prose th,.prose td{border:1px solid var(--line);padding:8px 10px;text-align:left}
.prose th{background:#f1f5f9}
@media(max-width:600px){.related ul{columns:1}h1{font-size:1.55rem}}