:root{--navy:#112f43;--ink:#173447;--muted:#5c7080;--blue:#087e9b;--orange:#e48142;--line:#dce5eb;--paper:#f2f6f8;--white:#fff;--soft:#eaf5f8;font-family:'DM Sans',system-ui,sans-serif;color:var(--ink);background:var(--paper);font-synthesis:none}*{box-sizing:border-box}body{margin:0;font-size:16px;line-height:1.6}button,input,select{font:inherit}button,a,input,select{touch-action:manipulation}a{color:var(--blue);text-underline-offset:4px}button{cursor:pointer}button:disabled{opacity:.45;cursor:default}:focus-visible{outline:3px solid #ed9b62;outline-offset:3px}.skip{position:fixed;top:-100px;left:20px;z-index:10;padding:10px;background:var(--white)}.skip:focus{top:10px}header{background:var(--white);border-bottom:1px solid var(--line)}.nav{max-width:1280px;margin:auto;padding:21px 34px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:11px;color:var(--ink);font:800 21px 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summary{font-size:14px;cursor:pointer;font-weight:500}.ratios dl{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:0;font-size:14px}.ratios dt{color:var(--muted)}.ratios dd{margin:0;font-weight:600}.below{margin-top:50px}.section-intro{display:flex;justify-content:space-between;gap:20px;align-items:flex-end;margin-bottom:20px}.section-intro h2{margin:0}.section-intro a{font-size:14px}.guide-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.guide-card{display:block;padding:24px;background:var(--white);border:1px solid var(--line);border-radius:9px;text-decoration:none;color:var(--ink);transition:transform .15s,border-color .15s}.guide-card:hover{border-color:#83b3c3;transform:translateY(-2px)}.guide-card .guide-no{font:700 12px 'Manrope',sans-serif;letter-spacing:.1em;color:var(--blue)}.guide-card h3{margin:14px 0 9px;font-size:18px}.guide-card p{font-size:14px;color:var(--muted);margin:0}.guide-card 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a{color:var(--muted);text-decoration:none}.footer-links a:hover{color:var(--blue)}.article{max-width:790px;margin:auto;padding-top:15px}.breadcrumb{font-size:13px;color:var(--muted);margin-bottom:20px}.breadcrumb a{text-decoration:none}.article h1{font-size:38px}.article .article-meta{font-size:13px;color:var(--muted);margin:14px 0 25px}.article h2{font-size:24px;margin-top:32px}.article h3{margin-top:22px}.article p,.article li{font-size:16px;line-height:1.8}.article ul,.article ol{padding-left:23px}.article .formula-box{background:var(--navy);color:#eaf8ff;border-radius:9px;padding:24px 28px;margin:24px 0;font:600 21px 'Manrope',sans-serif;overflow-wrap:anywhere}.article .example-box{background:var(--white);padding:23px 27px;border:1px solid var(--line);border-radius:8px;margin:23px 0}.article .example-box p:first-child{margin-top:0}.article .example-box p:last-child{margin-bottom:0}.article .try{display:inline-block;background:var(--blue);color:white;border-radius:6px;text-decoration:none;padding:10px 17px;margin:10px 0;font-size:15px;font-weight:500}.article table{width:100%;border-collapse:collapse;font-size:15px;margin:20px 0}.article th,.article td{text-align:left;padding:12px 14px;border-bottom:1px solid var(--line)}.article th{background:var(--white)}.article .article-faq details{padding:15px 0;border-bottom:1px solid var(--line)}.article .article-faq summary{cursor:pointer;font-weight:600}.article .article-faq p{margin:10px 0}.article .source-list{font-size:14px}.hidden,[hidden]{display:none!important}.print-only{display:none}.print-context{font-size:13px;color:var(--muted);margin-top:10px}.no-js{padding:15px;border:1px solid #efba8d;background:#fff1e4;color:#774021}.invalid .metric dd{color:var(--muted)}
@media(min-width:1450px){main{padding-top:38px}.diagram{height:310px}}
@media(max-width:1050px){.workspace{grid-template-columns:320px minmax(0,1fr);gap:18px}.inputpanel{padding:20px}.diagram-wrap,.result-body,.workings{padding:20px}.metric{padding:10px}.metric dd{font-size:19px}.privacy-note{display:none}.additional{flex-direction:column;gap:3px}}
@media(max-width:760px){.nav{padding:16px 20px}.brand{font-size:20px}.logo{width:31px;height:31px}.navlinks{gap:17px}.navlinks a{font-size:13px}.navlinks .navcalc{display:none}main{padding:24px 18px 42px}h1{font-size:29px}.heading{margin-bottom:21px}.lede{font-size:15px}.workspace{display:block}.inputpanel{margin-bottom:18px}.field-row{gap:15px}.presets{margin-top:10px}.diagram{height:auto;min-height:230px}.result-body{padding:20px}.metric-grid{gap:9px}.metric dd{font-size:20px}.metric dt{font-size:12px}.additional{flex-direction:row;flex-wrap:wrap}.workings{padding:20px;margin-top:18px}.below{margin-top:35px}.guide-grid{grid-template-columns:1fr}.guide-card{padding:22px}.guide-card h3{margin-top:10px}.guide-card .readtime{margin-top:13px}.faq{grid-template-columns:1fr;gap:12px;margin-top:32px}.principle{display:block}.principle h3{margin-bottom:9px}.footer-inner{display:block;padding:24px 20px}.footer-links{margin-top:15px;gap:16px}.article h1{font-size:31px}.article .formula-box{font-size:18px;padding:20px}.workings-head{align-items:flex-start}.toggle{white-space:nowrap}.article table{font-size:13px}.article th,.article td{padding:9px 6px}}
@media(max-width:390px){.navlinks{gap:11px}.nav{padding:15px}.brand{font-size:18px}.metric-grid{grid-template-columns:repeat(2,1fr)}.diagram-caption{flex-direction:column;gap:0}.diagram-caption span:last-child{text-align:left}.actions .action{padding:8px 10px}.workings-head{display:block}.toggle{margin-top:10px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
@media print{body{background:var(--white);color:#000;font-size:12px}header,footer,.heading .privacy-note,.inputpanel,.actions,.action-status,.below,.toggle,.skip,.print-context,.breadcrumb,.article .try{display:none!important}main{padding:0;max-width:none}.heading{margin-bottom:12px}h1{font-size:22px}.workspace{display:block}.panel{border:1px solid #bbb;box-shadow:none;break-inside:avoid}.diagram-wrap{background:var(--white);color:#000;padding:12px}.diagram-header span,.diagram-caption{color:#555}.diagram{height:200px}.diagram .edge{fill:none;stroke:#222}.diagram text,.diagram .known,.diagram .unknown{fill:#000}.diagram .tag{fill:white;stroke:#ddd}.diagram-header h2{font-size:15px}.result-body{padding:12px}.metric{background:var(--white)!important;border-color:#ddd!important}.metric dd{font-size:17px!important;color:#000!important}.workings{padding:14px;margin-top:13px}.solution-step{padding:8px 0}.equation{font-size:13px}.explanation,.checks{font-size:12px}.print-only{display:block}.article{max-width:none}.article h1{font-size:26px}.article p,.article li{font-size:12px}.article .formula-box{background:var(--white);color:black;border:1px solid #bbb}.article h2{font-size:19px}.print-only{font-size:12px;color:#555}}

.legal-cards{grid-template-columns:repeat(2,minmax(0,1fr));margin:26px 0}.legal-cards h2{font-size:20px;margin-top:12px}.legal-cards p{font-size:15px}.article .legal-cards .guide-card{padding:22px}
@media(max-width:760px){.nav{flex-wrap:wrap;gap:12px}.navlinks{width:100%;flex-wrap:wrap;gap:8px 20px}.navlinks a{font-size:14px}.legal-cards{grid-template-columns:1fr}}

.formula-reference{margin-bottom:42px}.formula-reference>p{max-width:920px;color:var(--muted)}.formula-layout{display:grid;grid-template-columns:1.2fr 1fr;gap:32px;margin-top:24px}.formula-layout p{color:var(--muted)}.table-scroll{overflow-x:auto}.formula-reference table{width:100%;border-collapse:collapse;font-size:14px;background:var(--white)}.formula-reference caption{text-align:left;color:var(--muted);padding:0 0 9px}.formula-reference th,.formula-reference td{text-align:left;padding:12px;border-bottom:1px solid var(--line)}.formula-reference th{background:var(--soft)}.formula-reference td:last-child{white-space:nowrap}.breadcrumb{margin-bottom:20px;display:flex;flex-wrap:wrap;gap:6px;font-size:13px;color:var(--muted)}@media(max-width:900px){.formula-layout{grid-template-columns:1fr;gap:20px}}

:root{color-scheme:light}.nav{flex-wrap:wrap}.brand{white-space:nowrap}.logo{flex-shrink:0}.navlinks{flex-wrap:wrap;gap:12px 20px}.theme-switch{display:flex;align-items:center;gap:9px;background:var(--paper);border:1px solid var(--line);border-radius:6px;padding:9px 11px;color:var(--ink);font-size:14px;white-space:nowrap}.switch-track{width:30px;height:18px;border-radius:12px;background:#718898;padding:3px;display:block}.switch-track>span{display:block;width:12px;height:12px;background:#fff;border-radius:50%;transition:transform .15s}.theme-switch[aria-checked=true] .switch-track{background:#087e9b}.theme-switch[aria-checked=true] .switch-track>span{transform:translateX(12px)}
@media screen{
:root[data-theme=dark]{color-scheme:dark;--ink:#e4edf4;--muted:#a9bac8;--blue:#83d4e8;--line:#344956;--paper:#0c1720;--white:#152733;--soft:#203b49}
[data-theme=dark] .mode-option input:checked+span{border-color:#507785}
[data-theme=dark] input,[data-theme=dark] select{border-color:#506675}
[data-theme=dark] input::placeholder{color:#a1b3c0}
[data-theme=dark] .metric.emphasis{background:#34291f;border-color:#6d4b33}
[data-theme=dark] .metric.emphasis dd{color:#ffc18e}
[data-theme=dark] .feedback.error{color:#ffc3c3;background:#472830}
[data-theme=dark] .principle{background:var(--soft)}
[data-theme=dark] .action.primary,[data-theme=dark] .article .try{color:#092b3b}
[data-theme=dark] .no-js{background:#362a20;color:#ffd2aa;border-color:#705a42}
}
@media print{:root{--ink:#000;--muted:#555;--white:#fff;--paper:#fff;--soft:#fff;--blue:#000;--line:#bbb;color-scheme:light}}