:root{
  --spruce:#14532D;
  --dark:#0E3B20;
  --bg:#FAF9F6;
  --ink:#1F2937;
  --amber:#D97706;
  --line:#E5E1D8;
  --card:#FFFFFF;
  --muted:#6B7280;
  --soft:#EEF4EE;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;line-height:1.6;font-size:17px}
a{color:var(--spruce);text-decoration:underline;text-underline-offset:3px}
a:hover{color:var(--dark)}
.wrap{max-width:980px;margin:0 auto;padding:0 20px}
header.site{background:var(--dark);color:#fff;padding:22px 0 18px}
header.site .wrap{display:flex;flex-wrap:wrap;gap:12px;align-items:flex-end;justify-content:space-between}
.brand{font-size:30px;font-weight:800;letter-spacing:-0.02em;line-height:1.1;color:#fff;text-decoration:none}
.brand span{color:#FBBF24}
.tagline{color:#D1E7D6;font-size:14px;margin-top:4px}
nav.main{display:flex;gap:18px;flex-wrap:wrap;font-size:15px}
nav.main a{color:#fff;text-decoration:none;font-weight:600}
nav.main a:hover{text-decoration:underline}
.hero{padding:34px 0 10px}
.hero h1{font-size:36px;line-height:1.15;margin:0 0 12px;letter-spacing:-0.02em;color:var(--dark)}
.hero p{font-size:18px;max-width:720px;margin:0 0 14px}
.notice{background:#FFF7E6;border:1px solid #F2D492;border-left:5px solid var(--amber);border-radius:10px;padding:14px 16px;margin:18px 0}
.notice strong{color:#92400E}
.unitbar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:space-between;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin:18px 0}
.unitbar label{font-weight:700;font-size:14px}
.toggle{display:inline-flex;border:1px solid var(--line);border-radius:999px;overflow:hidden}
.toggle button{border:0;background:#fff;padding:8px 16px;font-weight:700;cursor:pointer;color:var(--ink);font-size:14px}
.toggle button[aria-pressed="true"]{background:var(--spruce);color:#fff}
.grid{display:grid;gap:20px;margin:22px 0 34px}
@media(min-width:760px){.grid.two{grid-template-columns:1fr 1fr}.hero h1{font-size:44px}}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px;box-shadow:0 1px 3px rgba(0,0,0,.04)}
.card h2{margin:0 0 6px;font-size:24px;line-height:1.25;color:var(--dark)}
.card h3{margin:18px 0 8px;font-size:17px;color:var(--dark)}
.card p{margin:8px 0}
.kicker{font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--amber);font-weight:800;margin:0 0 6px}
.unofficial{display:inline-block;background:#FEF3C7;border:1px solid #F59E0B;color:#92400E;font-weight:800;font-size:13px;letter-spacing:.04em;text-transform:uppercase;padding:4px 9px;border-radius:999px;margin:6px 0}
label.field{display:block;font-weight:700;font-size:14px;margin:12px 0 4px}
input,select{width:100%;padding:10px 12px;border:1px solid #D1D5DB;border-radius:10px;font-size:16px;background:#fff;color:var(--ink)}
input:focus,select:focus{outline:2px solid var(--spruce);outline-offset:1px}
.row{display:grid;gap:12px}
@media(min-width:560px){.row.two{grid-template-columns:1fr 1fr}.row.three{grid-template-columns:1fr 1fr 1fr}}
.result{background:var(--soft);border:1px solid #CDE3D0;border-radius:12px;padding:14px 16px;margin-top:16px}
.result .big{font-size:30px;font-weight:800;color:var(--dark);line-height:1.2}
.result p{margin:4px 0}
.example{background:#F9FAF7;border:1px dashed #B9CDBB;border-radius:10px;padding:12px 14px;margin-top:14px;font-size:15px}
.example strong{color:var(--dark)}
.formula{font-size:14px;color:var(--muted);margin-top:10px}
table{width:100%;border-collapse:collapse;font-size:14px;margin-top:12px}
th,td{border-bottom:1px solid var(--line);padding:6px 4px;text-align:center}
th{background:var(--soft);color:var(--dark);font-size:12px;text-transform:uppercase;letter-spacing:.05em}
td input{padding:6px 6px;font-size:14px;text-align:center;min-width:52px}
.tablewrap{overflow-x:auto}
.btn{display:inline-block;background:var(--spruce);color:#fff;border:0;border-radius:10px;padding:10px 18px;font-weight:700;cursor:pointer;font-size:15px;text-decoration:none}
.btn:hover{background:var(--dark);color:#fff}
.btn.secondary{background:#fff;color:var(--spruce);border:1px solid var(--spruce)}
.small{font-size:14px;color:var(--muted)}
.pillnav{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0}
.pillnav a{background:#fff;border:1px solid var(--line);border-radius:999px;padding:7px 13px;text-decoration:none;font-size:14px;font-weight:600}
footer.site{border-top:1px solid var(--line);margin-top:40px;padding:26px 0 36px;background:#fff}
footer.site .wrap{display:flex;flex-wrap:wrap;gap:14px;justify-content:space-between;align-items:flex-start}
footer.site nav{display:flex;gap:16px;flex-wrap:wrap}
footer.site nav a{text-decoration:none;font-weight:600;font-size:15px}
.prose{max-width:760px;padding:28px 0 10px}
.prose h1{color:var(--dark);font-size:36px;line-height:1.2;margin:0 0 14px}
.prose h2{color:var(--dark);margin:26px 0 8px;font-size:22px}
.check{display:flex;gap:8px;align-items:center;font-weight:600;font-size:15px;margin-top:14px}
.check input{width:auto}

/* Wave 2 accessibility: visible focus state on every interactive element */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible { outline: 3px solid #B45309; outline-offset: 2px; }
.kicker { color: #92400E; }