:root{--ink:#111827;--muted:#586174;--line:#e5e7eb;--paper:#fff;--soft:#fff7ed;--accent:#ea580c;--accent-dark:#c2410c;--blue:#2563eb;--green:#166534;--red:#b91c1c}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;background:linear-gradient(180deg,#fff 0,#fafafa 55%,#f8fafc 100%);color:var(--ink);line-height:1.68}
.page-shell{width:min(1120px,calc(100% - 40px));margin:auto}
.site-header{padding:28px 0 18px}.brand{font-size:1.9rem;font-weight:900;color:#000;text-decoration:none;letter-spacing:-.03em}.crumbs{display:flex;flex-wrap:wrap;gap:8px;margin-top:8px;color:#6b7280;font-size:.92rem}.crumbs a{color:#4b5563;text-decoration:none}.crumbs a:hover{color:var(--accent)}
.hero{padding:30px 0 26px;max-width:850px}.eyebrow{color:var(--accent-dark);font-weight:800;text-transform:uppercase;letter-spacing:.09em;font-size:.75rem}.hero h1{font-size:clamp(2.1rem,5vw,3.55rem);line-height:1.06;letter-spacing:-.045em;margin:8px 0 14px}.hero p{font-size:1.12rem;color:var(--muted);max-width:760px}
.tool-layout{display:grid;grid-template-columns:minmax(0,1.06fr) minmax(300px,.94fr);gap:24px;align-items:start;margin-bottom:42px}.calculator-panel,.result-panel{background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:0 12px 35px rgba(17,24,39,.06)}.calculator-panel{padding:28px}.result-panel{padding:28px;position:sticky;top:18px;min-height:270px}.panel-kicker{font-size:.78rem;text-transform:uppercase;letter-spacing:.08em;color:#7c2d12;font-weight:800}.calculator-panel h2,.result-panel h2{font-size:1.35rem;margin:4px 0 18px}.field-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px}.field.full{grid-column:1/-1}.field label{display:block;font-weight:700;font-size:.93rem;margin-bottom:6px}.field small{display:block;color:#6b7280;font-size:.8rem;margin-top:5px}.field input,.field select,.field textarea{width:100%;border:1px solid #cbd5e1;border-radius:10px;background:#fff;padding:11px 12px;font:inherit;color:var(--ink)}.field textarea{min-height:105px;resize:vertical}.field input:focus,.field select:focus,.field textarea:focus{outline:3px solid #ffedd5;border-color:#fb923c}.button-row{display:flex;gap:11px;margin-top:22px}.primary-btn,.secondary-btn{border:0;border-radius:10px;padding:12px 18px;font:inherit;font-weight:800;cursor:pointer}.primary-btn{background:var(--accent);color:#fff}.primary-btn:hover{background:var(--accent-dark)}.secondary-btn{background:#f3f4f6;color:#374151}.error{display:none;margin-top:16px;padding:11px 13px;border-radius:9px;background:#fef2f2;color:var(--red);font-weight:650}.error.show{display:block}
.result-placeholder{color:#6b7280;padding:22px 0}.result-content{display:none}.result-content.show{display:block}.answer-label{color:#6b7280;font-size:.85rem;text-transform:uppercase;letter-spacing:.07em;font-weight:800}.answer{font-size:clamp(2rem,5vw,3.25rem);line-height:1.1;overflow-wrap:anywhere;color:#9a3412;font-weight:900;margin:7px 0 20px}.formula-box{background:#fff7ed;border-left:4px solid #fb923c;padding:13px 15px;border-radius:4px 10px 10px 4px;margin:14px 0;font-family:ui-monospace,SFMono-Regular,Consolas,monospace;overflow-wrap:anywhere}.steps{margin:16px 0 0 20px;color:#374151}.steps li{margin:7px 0;padding-left:3px}
.article,.article.wide,.article.narrow{width:100%;max-width:none;margin:0 0 28px;padding:0 27px}.article h2{font-size:clamp(1.45rem,3vw,1.9rem);line-height:1.25;letter-spacing:-.02em;margin-bottom:12px}.article h3{font-size:1.15rem;margin:22px 0 7px}.article p{color:#374151;margin:0 0 15px}.article ul,.article ol{margin:0 0 17px 24px;color:#374151}.article li{margin:7px 0}.article a{color:var(--blue);text-decoration-thickness:1px;text-underline-offset:3px}.article-card{max-width:none;background:#fff;border:1px solid var(--line);border-radius:14px;padding:25px 27px;box-shadow:0 5px 18px rgba(17,24,39,.035)}.example{border-top:3px solid #fdba74}.note{background:#fffbeb;border:1px solid #fde68a;border-radius:13px;padding:20px 22px}.formula-table{width:100%;border-collapse:collapse;margin:14px 0 8px}.formula-table th,.formula-table td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line)}.formula-table th{background:#f8fafc}
.split-article{display:grid;grid-template-columns:1fr 1fr;gap:28px;width:100%;max-width:none;margin:0}.split-article .article{margin:0;padding:0}.faq{width:100%;max-width:none;margin:42px 0}.faq h2{font-size:1.75rem;margin-bottom:16px;padding:0 18px}.faq details{background:#fff;border:1px solid var(--line);border-radius:11px;margin:10px 0;padding:0 18px}.faq summary{cursor:pointer;font-weight:800;padding:16px 0}.faq details p{color:#4b5563;padding:0 0 16px}.next-reading{width:100%;max-width:none;margin:34px 0 54px;padding:22px 27px 0;border-top:1px solid var(--line);color:#4b5563}.next-reading a{color:var(--blue)}
.site-footer{text-align:center;border-top:1px solid var(--line);margin-top:55px;padding:30px 20px;color:#9ca3af;font-size:.86rem}.site-footer a{color:#7b8494;text-decoration:none;margin:0 7px}
body.layout-notebook .calculator-panel{border-radius:5px;border-left:5px solid #fb923c}body.layout-notebook .result-panel{border-radius:5px}body.layout-notebook .article-card{border-radius:5px}
body.layout-compact .hero{padding-bottom:18px}body.layout-compact .tool-layout{grid-template-columns:.9fr 1.1fr}body.layout-compact .calculator-panel,body.layout-compact .result-panel{box-shadow:none}
body.layout-spacious .tool-layout{margin-bottom:60px}body.layout-spacious .article{margin-bottom:40px}body.layout-spacious .article-card{max-width:none;padding:34px 27px}
body.layout-data .result-panel{border-top:5px solid #f97316}body.layout-data .formula-box{background:#f8fafc;border-color:#64748b}
@media(max-width:760px){.page-shell{width:min(100% - 28px,1120px)}.site-header{padding-top:20px}.tool-layout,.split-article{grid-template-columns:1fr}.result-panel{position:static;min-height:230px}.calculator-panel,.result-panel{padding:21px}.field-grid{grid-template-columns:1fr}.field.full{grid-column:auto}.button-row{flex-direction:column}.hero h1{font-size:2.2rem}.article,.article.wide,.article.narrow{padding-left:0;padding-right:0}.article-card,body.layout-spacious .article-card{max-width:100%;padding:21px 0;border-left:0;border-right:0;border-radius:0;box-shadow:none}.faq h2{padding:0}.formula-table{display:block;overflow-x:auto;white-space:nowrap}}