:root{--ink:#172b25;--green:#173f35;--paper:#f7f5f0;--muted:#53615b;--line:#d9ded5;--accent:#a85124;--white:#fff;--serif:Georgia,'Times New Roman',serif}*{box-sizing:border-box}body{margin:0;color:var(--ink);background:var(--paper);font:17px/1.65 Arial,Helvetica,sans-serif}a{color:inherit;text-underline-offset:5px}img{max-width:100%;height:auto;display:block}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}:focus-visible{outline:3px solid #b76428;outline-offset:4px}button,.button{cursor:pointer}h1,h2,h3,p{margin-top:0}h1,h2{font-family:var(--serif);font-weight:400;line-height:1.1;letter-spacing:-.035em}h1{font-size:clamp(42px,4.4vw,66px)}h2{font-size:clamp(33px,3.3vw,48px)}h3{font-size:22px;line-height:1.3;font-weight:500}.wrap{max-width:1240px;margin:auto;padding:0 28px}.topline{background:var(--green);color:#e8eee7;font-size:12px;letter-spacing:.09em;text-transform:uppercase;padding:9px 0}.topline 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var(--line);margin-top:25px}.row{display:grid;grid-template-columns:70px 1fr;gap:16px;padding:20px 0;border-bottom:1px solid var(--line)}.row b{font-size:13px;color:var(--accent)}.row h3{font-size:19px;margin-bottom:7px}.row p{font-size:15px;margin:0;color:var(--muted)}.dark .eyebrow{color:#e0b28c}.dark p{color:#d3ded6}.dark .button{background:#f0e9db;color:var(--green);border-color:#f0e9db}.tool-preview{border:1px solid #759085;padding:35px}.tool-preview .big{font:58px var(--serif);color:white}.tool-preview small{display:block;color:#d3ded6}.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}.steps article{padding-top:22px;border-top:1px solid var(--line)}.steps strong{font:29px var(--serif);color:var(--accent)}.steps h3{margin-top:16px;font-size:19px}.steps p{font-size:14px;color:var(--muted)}details{border-bottom:1px solid var(--line);padding:19px 0}summary{cursor:pointer;font-size:18px}details p{color:var(--muted);margin:14px 0 0;max-width:820px}.cta{display:flex;align-items:center;justify-content:space-between;gap:30px}.cta h2{margin-bottom:12px}.footer{background:#102b24;color:#dce3dc;padding:55px 0 25px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:50px}.footer a{display:block;text-decoration:none;margin:10px 0;font-size:14px}.footer .brand{font-size:24px}.footer p{font-size:14px;max-width:390px;color:#b9c9bf}.footer h3{font-size:13px;text-transform:uppercase;letter-spacing:.12em}.fineprint{border-top:1px solid #3b5047;margin-top:35px;padding-top:24px;display:flex;justify-content:space-between;font-size:12px;color:#b9c9bf}.fineprint a{display:inline;margin-left:18px;font-size:12px}.breadcrumb{font-size:12px;color:var(--muted);padding-top:25px}.inner-hero{padding:55px 0;max-width:890px}.inner-hero h1{font-size:clamp(38px,4.3vw,62px)}.inner-hero .lead{font-size:20px;color:var(--muted)}.article-layout{display:grid;grid-template-columns:minmax(0,760px) 290px;gap:65px;align-items:start;padding-bottom:70px}.article-layout h2{font-size:31px;margin-top:40px}.article-layout p{color:var(--muted)}.article-layout aside{background:#eeece4;padding:26px;position:sticky;top:24px;font-size:14px}.article-layout aside a{display:block;margin:15px 0}.article-layout aside img{margin-bottom:24px}.article-layout ul{padding-left:20px}.sources{font-size:13px;border-top:1px solid var(--line);margin-top:35px;padding-top:20px}.tool-layout{display:grid;grid-template-columns:1.1fr 1fr;gap:35px;margin-bottom:70px}.panel{padding:32px;border:1px solid var(--line);background:white}.fields{display:grid;grid-template-columns:1fr 1fr;gap:20px}.field{display:flex;flex-direction:column;font-size:14px;gap:7px}.field input,.field select,.field textarea{border:1px solid #9aaba2;padding:12px;width:100%;color:var(--ink);background:white;border-radius:0}.full{grid-column:1/-1}.field textarea{min-height:130px}.help{font-size:13px;color:var(--muted)}.results{background:var(--green);color:white;padding:35px}.results h2{font-size:30px}.result-line{display:flex;justify-content:space-between;gap:20px;padding:18px 0;border-bottom:1px solid #567063}.result-line strong{font-size:23px}.error{color:#a52819;font-weight:600}.status{padding:15px;border:1px solid var(--line);margin-top:20px}.hidden,[hidden]{display:none!important}.notice{border-left:3px solid var(--accent);padding:16px 20px;background:#eee9de;font-size:14px;margin:20px 0}.form-actions{display:flex;gap:16px;margin-top:24px}.check{display:flex;gap:10px;align-items:start;font-size:14px}.check input{margin-top:7px}.honeypot{position:absolute;left:-9999px}.gallery{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;margin:30px 0}.gallery img{width:100%;aspect-ratio:1;object-fit:contain}.table-wrap{overflow-x:auto}table{border-collapse:collapse;width:100%;font-size:15px}td,th{text-align:left;padding:14px;border-bottom:1px solid var(--line)}th{background:#ebece5}.skip{position:absolute;left:-9999px}.skip:focus{left:15px;top:10px;background:white;padding:10px;z-index:5}@media(max-width:1080px){.nav{gap:13px}.nav .button{display:none}.hero{gap:30px}.article-layout{grid-template-columns:minmax(0,1fr) 250px;gap:35px}}@media(max-width:760px){.wrap{padding:0 20px}.topline .wrap span:last-child{display:none}.head{min-height:76px;justify-content:space-between}.menu-toggle{display:block}.nav{display:none;position:absolute;z-index:10;top:112px;left:0;right:0;background:var(--paper);padding:25px;box-shadow:0 15px 20px #0001;margin:0}.nav.open{display:flex;flex-direction:column;align-items:stretch}.nav .button{display:flex}.hero{grid-template-columns:1fr;padding-top:38px;gap:30px}.hero-media img{max-height:420px;border-radius:100px 3px 3px 3px}.hero-actions .button{flex:1}.hero-bottom{gap:16px}.strip .wrap{flex-wrap:wrap;gap:12px}.strip span{font-size:12px}.section{padding:55px 0}.section-heading{display:block}.section-heading p{margin-top:20px}.cards,.split,.tool-layout,.article-layout{grid-template-columns:1fr}.cards{gap:20px}.split{gap:35px}.steps{grid-template-columns:1fr 1fr}.cta{display:block}.cta .button{margin-top:20px}.footer-grid{grid-template-columns:1fr 1fr;gap:25px}.footer-grid>div:first-child{grid-column:1/-1}.fineprint{display:block}.fineprint a{margin:10px 15px 0 0}.article-layout aside{position:static}.inner-hero{padding:40px 0}.fields{grid-template-columns:1fr}.panel,.results{padding:22px}.tool-preview{padding:25px}.gallery{gap:12px}h1{overflow-wrap:normal}.result-line strong{font-size:20px}.button{gap:12px;font-size:13px;padding:14px 16px}}@media(prefers-reduced-motion:no-preference){a,button{transition:background .18s,color .18s}}
/* Product-led presentation */
.fuel-hero{background:#eae8de}.fuel-hero-grid{display:grid;grid-template-columns:1fr 1fr;align-items:stretch;padding-right:0;max-width:1440px}.fuel-hero-copy{padding:72px 55px 65px 70px}.fuel-hero-copy h1{font-size:clamp(42px,4.5vw,68px)}.fuel-hero-copy .lead{max-width:490px;color:var(--muted)}.hero-footnote{font-size:12px;margin:36px 0 0;color:var(--muted)}.fuel-hero-photo{position:relative;min-width:0;background:#f8f8f5;display:flex;flex-direction:column;justify-content:center}.fuel-hero-photo>img{width:100%;height:100%;object-fit:cover;max-height:690px}.photo-caption{display:flex;justify-content:space-between;padding:16px 24px;background:var(--green);color:#fff;font-size:10px;letter-spacing:.1em}.index-strip{background:#fff;border-bottom:1px solid var(--line)}.index-strip .wrap{display:flex;justify-content:space-between;gap:20px;padding-top:22px;padding-bottom:22px}.index-strip a{font-size:12px;text-decoration:none}.product-feature{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:75px}.product-visual{position:relative;background:#f4f3ee}.product-visual img{width:100%;aspect-ratio:1;object-fit:contain}.visual-label{display:block;border-top:1px solid var(--line);padding:17px 20px;font-size:11px;letter-spacing:.12em}.product-points{display:grid;grid-template-columns:1fr 1fr;gap:25px;margin:30px 0;border-top:1px solid var(--line);padding-top:20px}.product-points span{display:block;color:var(--accent);font-size:12px;margin-bottom:12px}.product-points strong{font-size:15px;font-weight:500}.product-points p{font-size:13px;color:var(--muted);margin:8px 0}.application-list{border-top:1px solid #a7b2a8}.application-list>a{display:grid;grid-template-columns:50px 1fr 1fr 30px;gap:20px;align-items:center;text-decoration:none;padding:27px 0;border-bottom:1px solid #a7b2a8}.application-list span{font-size:13px;color:var(--accent)}.application-list h3,.application-list p{margin:0}.application-list p{font-size:14px;color:var(--muted)}.application-list>a:hover h3{color:var(--accent)}.evidence-grid{display:grid;grid-template-columns:1.1fr 1fr;gap:85px;align-items:center}.evidence-sheet{background:#f2f1e9;color:var(--ink);padding:35px}.dark .evidence-sheet .eyebrow{color:var(--accent)}.evidence-sheet>div{display:flex;gap:22px;border-top:1px solid var(--line);padding:15px 0}.evidence-sheet span{color:var(--accent);font-size:12px}.dark .evidence-sheet p{color:var(--ink);margin:0}.evidence-sheet strong{font-weight:500;display:block}.evidence-sheet small{display:block;font-size:12px;color:var(--muted);margin-top:5px}.evidence-sheet .help{padding-top:18px}.energy-example{background:#eeece3;padding:38px}.energy-inputs{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.energy-inputs span{font-size:12px;color:var(--muted)}.energy-inputs b{display:block;font:32px var(--serif);color:var(--ink);margin-bottom:7px}.energy-result{border-top:1px solid #aeb6a9;margin-top:30px;padding:25px 0}.energy-result>span{font-size:13px;display:block}.energy-result strong{font:64px var(--serif);display:block}.energy-result small{font:16px Arial}.faq-layout{display:grid;grid-template-columns:1fr 1.5fr;gap:80px}.faq-layout details:first-child{padding-top:0}.product-opening{padding-top:42px}.product-gallery>img{width:100%;aspect-ratio:1.1;object-fit:contain;background:#fff}.product-gallery>div{display:grid;grid-template-columns:1fr 1fr;gap:15px;margin-top:15px}.product-gallery>div img{width:100%;height:150px;object-fit:cover}.product-summary{margin:28px 0}.product-summary>div{border-top:1px solid var(--line);padding:13px 0;display:grid;grid-template-columns:1fr 1.2fr;gap:15px;font-size:13px}.product-summary dd{margin:0;color:var(--muted)}.product-opening .help{margin-top:20px}.table-wrap tbody th{background:transparent;font-weight:500;width:30%}
@media(max-width:1080px){.fuel-hero-copy{padding:45px 30px 45px 0}.product-feature,.evidence-grid{gap:40px}}
@media(max-width:760px){.fuel-hero-grid{grid-template-columns:1fr;padding:0}.fuel-hero-copy{padding:40px 20px}.fuel-hero-photo>img{max-height:380px;object-fit:contain}.fuel-hero-copy h1{font-size:43px}.photo-caption{padding:15px 20px}.index-strip .wrap{display:grid;grid-template-columns:1fr 1fr;gap:12px}.product-feature,.evidence-grid,.faq-layout{grid-template-columns:1fr;gap:32px}.application-list>a{grid-template-columns:25px 1fr 20px;gap:12px}.application-list p{grid-column:2;grid-row:2}.application-list b{grid-column:3;grid-row:1}.application-list h3{font-size:21px}.evidence-sheet,.energy-example{padding:24px}.energy-inputs b{font-size:29px}.energy-result strong{font-size:55px}.product-gallery>div img{height:115px}.product-summary>div{grid-template-columns:1fr 1fr}.hero-footnote{margin-top:24px}.product-points{gap:16px}}
/* Brand colour expresses positioning; readable evidence supports trust. */
:root{--green:#194c3b;--ink:#17342b;--paper:#f5f6f0;--accent:#9b481d}.fuel-hero{background:#e9eee2}.comparison-columns{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin-bottom:24px}.comparison-columns fieldset{border:1px solid var(--line);padding:22px;min-width:0}.comparison-columns legend{font-weight:600;padding:0 8px}.comparison-columns .field{margin-bottom:14px}#comparison-results{margin-top:24px}#comparison-results .help{margin-top:20px}#comparison-results .result-line strong{color:var(--green)}@media(max-width:760px){.comparison-columns{grid-template-columns:1fr;gap:14px}}

/* Procurement worksheets stay readable on narrow screens. */
.table-wrap { max-width:100%; overflow-x:auto; }
.table-wrap caption { text-align:left; padding:12px 0; font-weight:600; color:var(--ink); }
.article-layout > article, .article-layout > aside { min-width:0; }
.article-layout .table-wrap table { min-width:0; width:100%; }
.article-layout th, .article-layout td { overflow-wrap:anywhere; }
.sources a { overflow-wrap:anywhere; }
#comparison-results .field { margin-top:24px; }
#comparison-results textarea { min-height:220px; font:inherit; }
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible { outline:3px solid #9b481d;outline-offset:4px; }
@media(max-width:600px){.article-layout th,.article-layout td { padding:12px 9px; font-size:14px; }}

.analytics-choice{position:fixed;bottom:0;left:0;right:0;z-index:1000;background:#fff;border-top:2px solid #1c493a;padding:1rem max(1rem,calc((100vw - 1180px)/2));box-shadow:0 -4px 24px #0002;max-height:60vh;overflow:auto}.analytics-choice[hidden]{display:none}.analytics-choice p{margin:.35rem 0;font-size:.9rem;max-width:70ch}.analytics-choice .form-actions{margin:.6rem 0 0;display:flex;flex-wrap:wrap;gap:.75rem}.analytics-settings{background:transparent;color:inherit;border:1px solid currentColor;padding:.5rem;cursor:pointer;font:inherit}#analytics-status{display:block;font-size:.8rem}