:root{
  --bg:#f5f7fb;--surface:#fff;--surface-2:#f8fafc;--text:#0f172a;--muted:#64748b;
  --border:#dbe3ee;--border-soft:#e8eef5;--accent:#2563eb;--accent-hover:#1d4ed8;
  --success:#15803d;--danger:#b91c1c;--shadow:0 12px 28px rgba(15,23,42,.06)
}
:root[data-theme="dark"]{
  --bg:#0b1120;--surface:#111827;--surface-2:#0f172a;--text:#f8fafc;--muted:#94a3b8;
  --border:#283548;--border-soft:#1d2939;--accent:#60a5fa;--accent-hover:#93c5fd;
  --success:#4ade80;--danger:#f87171;--shadow:0 12px 28px rgba(0,0,0,.22)
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;-webkit-font-smoothing:antialiased}a{color:inherit}.topbar,.hero,.tools-section,.faq,footer{width:min(1120px,calc(100% - 32px));margin:0 auto}.topbar{display:flex;align-items:center;gap:18px;padding:18px 0;border-bottom:1px solid var(--border-soft)}.brand{font-size:1.45rem;font-weight:850;text-decoration:none;letter-spacing:-.03em}.brand span{color:var(--accent)}nav{display:flex;gap:20px;margin-left:auto}nav a,.footer-links a{font-size:.92rem;color:var(--muted);text-decoration:none}nav a:hover,.footer-links a:hover{color:var(--text)}.header-actions{display:flex;align-items:center;gap:8px}.share-icons{display:flex;gap:5px}.icon-btn,.language-select{height:36px;border:1px solid var(--border);border-radius:9px;background:var(--surface);color:var(--text);font:inherit}.icon-btn{min-width:36px;padding:0 9px;cursor:pointer;font-size:.78rem;font-weight:750}.icon-btn:hover{background:var(--surface-2)}.language-select{padding:0 8px}.hero{padding:44px 0 24px;max-width:1120px}.badge{display:inline-flex;padding:7px 10px;border:1px solid var(--border);border-radius:999px;background:var(--surface);color:var(--muted);font-size:.78rem;font-weight:700}.hero h1{max-width:720px;margin:16px 0 12px;font-size:clamp(2.2rem,5vw,4rem);line-height:1;letter-spacing:-.05em}.hero p{max-width:700px;margin:0;color:var(--muted);line-height:1.7;font-size:1.03rem}.tools-section{padding:14px 0 26px}.category-tabs{display:flex;gap:8px;overflow:auto;padding-bottom:12px}.category-tab{white-space:nowrap;border:1px solid var(--border);border-radius:999px;background:var(--surface);color:var(--muted);padding:9px 13px;font:inherit;font-size:.86rem;font-weight:650;cursor:pointer}.category-tab.active{background:var(--text);color:var(--bg);border-color:var(--text)}.calculator-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.calc-card{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:18px;box-shadow:var(--shadow);transition:opacity .18s ease,transform .18s ease}.calc-card.hidden-category{display:none}.calc-head{display:flex;gap:12px;align-items:flex-start;margin-bottom:16px}.calc-index{display:grid;place-items:center;flex:0 0 auto;width:32px;height:32px;border-radius:9px;background:var(--surface-2);border:1px solid var(--border);color:var(--accent);font-size:.72rem;font-weight:850}.calc-head h2{margin:0 0 4px;font-size:1.02rem}.calc-head p{margin:0;color:var(--muted);font-size:.86rem;line-height:1.5}.two-inputs{display:grid;grid-template-columns:1fr 1fr;gap:10px}.two-inputs label{display:flex;flex-direction:column;gap:6px;color:var(--muted);font-size:.82rem}.calc-card input,.calc-card select{width:100%;border:1px solid var(--border);border-radius:10px;background:var(--surface-2);color:var(--text);padding:11px 12px;font:inherit;outline:none}.calc-card input:focus{border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 12%,transparent)}.formula-row{display:grid;grid-template-columns:1fr auto auto 1fr;align-items:center;gap:8px}.formula-row>span{color:var(--muted);font-size:.9rem}.answer{margin-top:14px;padding:13px 14px;border-radius:12px;background:var(--surface-2);border:1px solid var(--border-soft);display:flex;align-items:center;justify-content:space-between;gap:12px}.answer span{color:var(--muted);font-size:.8rem}.answer strong{font-size:1.35rem;letter-spacing:-.03em}.multi-answer,.triple-answer{display:grid;grid-template-columns:repeat(2,1fr);align-items:stretch}.triple-answer{grid-template-columns:repeat(3,1fr)}.multi-answer>div,.triple-answer>div{display:flex;flex-direction:column;gap:4px}.multi-answer>div+div,.triple-answer>div+div{padding-left:12px;border-left:1px solid var(--border)}.multi-answer strong,.triple-answer strong{font-size:1.05rem}.segmented{display:grid;grid-template-columns:1fr 1fr;gap:6px;padding:5px;border:1px solid var(--border);border-radius:11px;background:var(--surface-2);margin-bottom:12px}.seg-btn{border:0;border-radius:8px;padding:9px;background:transparent;color:var(--muted);font:inherit;font-size:.82rem;font-weight:700;cursor:pointer}.seg-btn.active{background:var(--surface);color:var(--text);box-shadow:0 1px 2px rgba(15,23,42,.08)}.rule-grid{display:grid;grid-template-columns:1fr auto 1fr;gap:8px;align-items:center}.rule-grid span{color:var(--muted)}.result-box{display:grid;place-items:center;min-height:43px;border-radius:10px;background:var(--surface-2);border:1px solid var(--border);font-weight:800}.wide-card{grid-column:1/-1}.faq{max-width:860px;padding:26px 0}.faq h2{font-size:1.55rem;letter-spacing:-.03em}.faq details{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:15px 17px;margin-bottom:9px}.faq summary{cursor:pointer;font-weight:700}.faq p{color:var(--muted);line-height:1.65;margin-bottom:0}footer{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:24px 0 36px;color:var(--muted)}footer strong{display:block;color:var(--text);margin-bottom:4px}.footer-links{display:flex;gap:14px}.toast{position:fixed;right:18px;bottom:18px;padding:10px 13px;border-radius:10px;background:var(--text);color:var(--bg);font-size:.86rem;z-index:50;box-shadow:var(--shadow)}
@media(max-width:780px){nav{display:none}.calculator-grid{grid-template-columns:1fr}.wide-card{grid-column:auto}.topbar{flex-wrap:wrap}.header-actions{margin-left:auto}.hero{padding-top:30px}.triple-answer{grid-template-columns:1fr}.triple-answer>div+div{padding-left:0;padding-top:8px;border-left:0;border-top:1px solid var(--border)}footer{flex-direction:column;align-items:flex-start}}
@media(max-width:520px){.topbar,.hero,.tools-section,.faq,footer{width:calc(100% - 20px)}.hide-small{display:none}.share-icons{display:none}.two-inputs{grid-template-columns:1fr}.formula-row{grid-template-columns:1fr auto;}.formula-row span:nth-of-type(2){display:none}.formula-row input:last-child{grid-column:1/-1}.multi-answer{grid-template-columns:1fr}.multi-answer>div+div{padding-left:0;padding-top:8px;border-left:0;border-top:1px solid var(--border)}}