:root{color-scheme:light;--ink:#243a33;--muted:#64746c;--paper:#fbfaf6;--card:#fff;--green:#276653;--soft:#e7eee5;--line:#e1e5dc;--accent:#dbb77b;font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:16px}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);line-height:1.65}a{color:var(--green);text-underline-offset:3px}a:hover{text-decoration-thickness:2px}button,input,select{font:inherit}button,a,input,select,summary{touch-action:manipulation}button{cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #b87829;outline-offset:3px}.shell{max-width:1160px;margin:auto;padding:0 30px}header{border-bottom:1px solid var(--line)}nav{min-height:85px;display:flex;align-items:center;justify-content:space-between;gap:18px}.brand{font-weight:750;text-decoration:none;color:var(--ink);display:flex;gap:10px;align-items:center}.brand svg{width:36px;height:36px}nav .links{display:flex;gap:24px;font-size:.88rem}nav .links a{text-decoration:none;color:var(--muted)}.skip{position:absolute;left:-9999px}.skip:focus{left:16px;top:10px;background:var(--card);padding:8px;z-index:3}.hero{padding:62px 0 32px;display:grid;grid-template-columns:1.2fr 1fr;gap:50px;align-items:center}.eyebrow{text-transform:uppercase;font-size:.7rem;letter-spacing:.18em;font-weight:750;color:var(--green)}h1,h2,h3,p{margin-top:0}h1{font-family:Georgia,"Times New Roman",serif;font-weight:500;font-size:clamp(2.5rem,5vw,4rem);line-height:1.1;letter-spacing:-.045em;margin:15px 0 20px}h2{font-family:Georgia,"Times New Roman",serif;font-weight:500;font-size:2rem;line-height:1.2;letter-spacing:-.02em}h3{font-size:1.05rem;line-height:1.4}.intro{max-width:580px;color:var(--muted);font-size:1.05rem}.tags{display:flex;flex-wrap:wrap;gap:8px}.tag{font-size:.73rem;border:1px solid var(--line);padding:5px 10px;border-radius:30px;color:var(--muted)}.method-art{background:var(--soft);border-radius:32px;padding:24px;position:relative}.method-art svg{width:100%;height:auto;display:block}.method-art figcaption{font-size:.78rem;text-align:center;color:var(--green);margin-top:7px}.workspace{display:grid;grid-template-columns:1.1fr .9fr;gap:25px;align-items:start;margin:18px 0 48px}.card{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:30px}.card h2{font-size:1.6rem;margin-bottom:6px}.hint,.small{color:var(--muted);font-size:.85rem}.small{line-height:1.65}.section-label{display:flex;align-items:center;gap:12px;margin:27px 0 14px;font-weight:700;font-size:.88rem}.number{width:25px;height:25px;display:inline-grid;place-items:center;background:var(--soft);border-radius:50%;font-size:.72rem;color:var(--green)}fieldset{border:0;padding:0;margin:0}legend{padding:0;width:100%}.grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}label{display:block;font-size:.78rem;font-weight:650;margin-bottom:6px}input,select{width:100%;border:1px solid #cbd4c9;border-radius:10px;padding:11px 12px;color:var(--ink);background:#fff;min-height:46px}input[aria-invalid=true]{border-color:#b6492e}.error{font-size:.75rem;color:#9b3825;display:block;min-height:0;margin-top:3px}.error:empty{display:none}.unit-row{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-top:20px}.unit-row select{width:160px}.unit-row label{margin:0}.range-line{display:flex;align-items:baseline;gap:8px}.range-line input{max-width:100px}.primary,.secondary{border-radius:10px;padding:12px 18px;min-height:46px;font-weight:650;font-size:.9rem}.primary{background:var(--green);color:#fff;border:1px solid var(--green);width:100%;margin-top:22px}.secondary{background:#fff;border:1px solid #bdcbbb;color:var(--green)}.text-button{border:0;background:transparent;text-decoration:underline;color:var(--green);font-size:.83rem;padding:5px 0}.button-row{display:flex;gap:10px;flex-wrap:wrap}.result{background:#edf2e8;position:sticky;top:22px}.result .eyebrow{margin-bottom:22px}.total{font-size:3.8rem;letter-spacing:-.05em;line-height:1.05;font-weight:650}.total span{font-size:1.1rem;letter-spacing:0;font-weight:500}.total-note{margin:10px 0 26px;color:var(--muted);font-size:.85rem}.result-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}.metric{padding:15px 0;border-top:1px solid #cfd9c8}.metric b{display:block;font-size:1.25rem;line-height:1.3}.metric span{font-size:.73rem;color:var(--muted)}.receipt{border-top:1px solid #cfd9c8;margin-top:16px;padding-top:17px;font-size:.8rem}.receipt div{display:flex;justify-content:space-between;gap:15px;margin:5px 0}.callout{background:#f5f4ee;border-radius:12px;padding:15px;font-size:.8rem;color:var(--muted);margin:20px 0}.status{font-size:.83rem;min-height:1.5em;color:var(--green);margin-bottom:10px}.status.error-summary{color:#9b3825}.result .button-row button{flex:1;font-size:.8rem}.result button:disabled{opacity:.45;cursor:default}.learn{border-top:1px solid var(--line);padding:40px 0}.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}.steps article{padding:20px 0}.steps .number{margin-bottom:14px}.steps p{font-size:.87rem;color:var(--muted)}details{border-top:1px solid var(--line);padding:17px 0}summary{font-weight:650;cursor:pointer;font-size:.9rem}details p{font-size:.88rem;color:var(--muted);margin:12px 0 0}.prose{max-width:780px;padding-top:52px;padding-bottom:58px}.prose h1{font-size:2.8rem}.prose h2{font-size:1.6rem;margin:33px 0 15px}.prose p,.prose li{color:var(--muted)}.formula{background:var(--soft);padding:18px;border-radius:12px;line-height:1.8;font-size:.9rem}.table-wrap{overflow-x:auto}table{border-collapse:collapse;width:100%;font-size:.85rem}th,td{text-align:left;padding:12px;border-bottom:1px solid var(--line)}footer{border-top:1px solid var(--line);padding:24px 0;color:var(--muted);font-size:.75rem}.footer-inner{display:flex;justify-content:space-between;gap:18px}.footer-inner div{display:flex;gap:15px}noscript p{border:1px solid var(--accent);padding:15px;border-radius:10px}.print-only{display:none}@media(max-width:820px){.hero{grid-template-columns:1fr;gap:18px;padding-top:35px}.hero figure{max-width:450px;margin:0}.workspace{grid-template-columns:1fr}.result{position:static}.steps{grid-template-columns:1fr;gap:0}.steps article{padding:12px 0}.shell{padding:0 20px}.card{padding:23px}.hero h1{font-size:3rem}.footer-inner{flex-direction:column}.method-art{padding:12px}}@media(max-width:420px){nav{align-items:flex-start;padding:17px 0;flex-direction:column;gap:9px;min-height:0}nav .links{gap:18px}.hero h1{font-size:2.5rem}.grid{gap:10px}.total{font-size:3.2rem}.unit-row select{width:130px}.card{padding:20px}.shell{padding:0 15px}}@media(prefers-reduced-motion:no-preference){button{transition:background .15s}button:hover:not(:disabled){filter:brightness(.95)}}@media print{nav,.hero figure,#calculator-form,.learn,.faq,.no-print,footer{display:none!important}body{background:white}.shell{max-width:none;padding:0}.hero{display:block;padding:0}.hero h1{font-size:2rem}.hero .tags{display:none}.workspace{display:block}.result{position:static;background:white;border:1px solid #bbb}.print-only{display:block;font-size:.85rem;white-space:pre-wrap}.card{break-inside:avoid}.result .button-row{display:none}}