:root{
  --bg:#f6f5f1;--card:#ffffff;--ink:#1b2130;--muted:#5b6475;--line:#e3e1da;
  --brand:#14324f;--brand-ink:#ffffff;--accent:#f2a516;--accent-ink:#1b1400;
  --ok-bg:#e6f4ea;--ok-ink:#1d5c2e;--warn-bg:#fff4dc;--warn-ink:#7a4b00;--bad-bg:#fde8e6;--bad-ink:#8a1f14;
  --out-bg:#f2f6fb;--link:#0f5c9e;--radius:12px;
  --font:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#11151d;--card:#1a202b;--ink:#e8ebf1;--muted:#a3abba;--line:#2c3443;
  --brand:#0c1a2b;--out-bg:#202a38;--link:#7cc0ff;
  --ok-bg:#16301f;--ok-ink:#9fe0b2;--warn-bg:#33270e;--warn-ink:#ffd27a;--bad-bg:#3a1714;--bad-ink:#ffaba0;
color-scheme:dark;}}
:root[data-theme="dark"]{
  --bg:#11151d;--card:#1a202b;--ink:#e8ebf1;--muted:#a3abba;--line:#2c3443;
  --brand:#0c1a2b;--out-bg:#202a38;--link:#7cc0ff;
  --ok-bg:#16301f;--ok-ink:#9fe0b2;--warn-bg:#33270e;--warn-ink:#ffd27a;--bad-bg:#3a1714;--bad-ink:#ffaba0;
color-scheme:dark;}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.6 var(--font)}
a{color:var(--link)}
img,svg{max-width:100%}
.wrap{max-width:1100px;margin:0 auto;padding:0 16px}
.site-head{background:var(--brand);color:var(--brand-ink)}
.site-head .wrap{display:flex;align-items:center;justify-content:space-between;gap:10px 16px;min-height:60px;flex-wrap:wrap;padding-top:8px;padding-bottom:8px}
.logo{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-weight:800;font-size:1.2rem;letter-spacing:-.01em}
.logo span b{color:var(--accent)}
.nav{display:flex;gap:4px 14px;flex-wrap:wrap;font-size:.92rem}
.nav a{color:#d6e2ef;text-decoration:none;padding:4px 0}
.nav a:hover{color:#fff;text-decoration:underline}
.head-right{display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.theme-toggle{background:none;border:1px solid rgba(255,255,255,.35);color:#fff;border-radius:6px;padding:.3rem .55rem;cursor:pointer;font:inherit;font-size:.9rem;white-space:nowrap}
.theme-toggle:hover{border-color:#fff}
@media (max-width:600px){.theme-toggle{padding:.2rem .4rem;font-size:.85rem}}
.crumbs{font-size:.85rem;color:var(--muted);margin:18px 0 6px}
.crumbs a{color:var(--muted)}
h1{font-size:clamp(1.6rem,4vw,2.3rem);line-height:1.2;margin:.2em 0 .35em;letter-spacing:-.02em}
h2{font-size:1.35rem;line-height:1.3;margin:1.8em 0 .5em}
h3{font-size:1.08rem;margin:1.4em 0 .4em}
.lead{font-size:1.08rem;color:var(--muted);max-width:760px;margin:0 0 18px}
.calc{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);gap:0;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.calc form{padding:20px}
.results{padding:20px;background:var(--out-bg);border-left:1px solid var(--line)}
@media (max-width:760px){.calc{grid-template-columns:minmax(0,1fr)}.results{border-left:0;border-top:1px solid var(--line)}}
.field{margin-bottom:14px}
.field label{display:block;font-weight:600;font-size:.93rem;margin-bottom:4px}
.field .row{display:flex;gap:8px}
.field input,.field select{font:inherit;color:var(--ink);background:var(--card);border:1px solid #b9bfca;border-radius:8px;padding:9px 11px;width:100%;min-width:0}
.field .row select.unit{width:auto;flex:0 0 auto}
.field .u{align-self:center;color:var(--muted);font-size:.92rem;white-space:nowrap;min-width:2.2em}
.field input:focus,.field select:focus{outline:3px solid rgba(242,165,22,.45);outline-offset:1px;border-color:var(--accent)}
.help{display:block;font-size:.82rem;color:var(--muted);margin-top:4px;line-height:1.45}
.results h2{font-size:.85rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0 0 10px}
.out{display:flex;justify-content:space-between;align-items:baseline;gap:12px;padding:9px 0;border-bottom:1px dashed var(--line)}
.out span{color:var(--muted);font-size:.93rem}
.out strong{font-size:1.05rem;text-align:right}
.out.main strong{font-size:1.6rem;color:var(--ink)}
.status{margin-top:14px;padding:10px 12px;border-radius:8px;font-size:.93rem;font-weight:600}
.status.ok{background:var(--ok-bg);color:var(--ok-ink)}
.status.warn{background:var(--warn-bg);color:var(--warn-ink)}
.status.bad{background:var(--bad-bg);color:var(--bad-ink)}
#extra{margin-top:12px;font-size:.92rem}
#extra table{margin-top:6px}
.content{max-width:780px}
.content p,.content li{max-width:72ch}
.formula{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:8px;padding:10px 14px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.92rem;overflow-x:auto;white-space:pre-wrap}
table{border-collapse:collapse;width:100%;font-size:.92rem;background:var(--card)}
th,td{border:1px solid var(--line);padding:6px 9px;text-align:left}
th{background:var(--out-bg)}
.tablewrap{overflow-x:auto}
.faq details{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:10px 14px;margin-bottom:8px}
.faq summary{cursor:pointer;font-weight:600}
.faq details p{margin:.6em 0 .2em}
.related{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:10px;margin:10px 0 30px}
.card{display:block;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:12px 14px;text-decoration:none;color:var(--ink)}
.card:hover{border-color:var(--accent)}
.card b{display:block;color:var(--link);margin-bottom:2px}
.card small{color:var(--muted);line-height:1.4;display:block}
.hero{padding:34px 0 10px}
.hero p{font-size:1.1rem;color:var(--muted);max-width:720px}
.search{width:100%;max-width:520px;font:inherit;padding:12px 14px;border-radius:10px;border:1px solid #b9bfca;background:var(--card);color:var(--ink);margin:8px 0 6px}
.cat-block h2 a{color:var(--ink);text-decoration:none}
.cat-block h2 a:hover{text-decoration:underline}
.cat-block p.cat-intro{color:var(--muted);margin-top:0}
.ad-slot{margin:22px 0}
.ad-slot:empty{display:none}
.site-foot{margin-top:50px;border-top:1px solid var(--line);padding:24px 0 40px;color:var(--muted);font-size:.88rem}
.site-foot .cols{display:flex;flex-wrap:wrap;gap:8px 18px;margin-bottom:10px}
.note{font-size:.88rem;color:var(--muted)}
.btn{display:inline-block;font:inherit;font-size:.9rem;background:var(--accent);color:var(--accent-ink);border:0;border-radius:8px;padding:8px 12px;cursor:pointer;font-weight:600}
.btn.ghost{background:transparent;color:var(--link);border:1px solid var(--line)}
.loads td input,.loads td select{width:100%;font:inherit;padding:6px 7px;border:1px solid #b9bfca;border-radius:6px;background:var(--card);color:var(--ink);min-width:60px}
.loads td{padding:4px}
.loads td:first-child input{min-width:150px}
.loads td input[type=number]{min-width:64px}
.calc form,.results{min-width:0}
.loads td.x{width:36px;text-align:center}
.loads button.del{background:none;border:0;color:var(--muted);font-size:1.1rem;cursor:pointer}