/* OnTrick Maths / October 2026 editorial layout. Standalone CSS, no frameworks. */
:root{--paper:#fff;--white:#fff;--ink:#1c2730;--green:#233b55;--rust:#a74d2c;--muted:#5d6670;--line:#dde1e4;--serif:Georgia,"Times New Roman",serif;--sans:Arial,Helvetica,sans-serif}
html{scroll-padding-top:20px}body{background:#fff;color:#1c2730;font:15px/1.65 Arial,Helvetica,sans-serif;-webkit-font-smoothing:auto}
a{color:inherit}a:hover{color:#b04a28}h1,h2,h3{letter-spacing:-.025em}h1,h2{font-family:Arial,Helvetica,sans-serif;font-weight:700}h1 em,h2 em{font-style:normal;color:inherit}.container{width:min(1120px,calc(100% - 52px));margin-left:auto;margin-right:auto}
/* Newspaper-style masthead */
.topline{display:none}.site-header{background:#fff;border:0;position:relative;z-index:20}.masthead-top{height:32px;border-bottom:1px solid #e0e2e2;display:flex;align-items:center;justify-content:space-between;font-size:11px;color:#5f6870}.masthead-top a{text-decoration:underline;text-underline-offset:3px}.masthead-main{min-height:105px;display:flex;align-items:center;justify-content:space-between}.site-header .brand{display:inline-flex;color:#172c42;gap:0}.site-header .brand-text{font-size:37px;font-weight:800;letter-spacing:-.065em;line-height:.95}.site-header .brand-text>span{color:#b64f31}.site-header .brand-text small{font:bold 11px/1.4 Arial,sans-serif;letter-spacing:.03em;margin-top:9px;color:#67727b}.masthead-tag{text-align:right;color:#777d81;font-size:12px}.navigation-wrap{border-top:3px solid #1e3d5d;border-bottom:1px solid #cbd4d9}.navigation-inner{min-height:48px;display:flex;align-items:center;justify-content:space-between}.desktop-nav{margin:0;gap:33px}.desktop-nav .nav-link{font-size:13px;font-weight:700;padding:12px 0}.desktop-nav .nav-link.active{color:#b64f31}.desktop-nav .nav-link.active:after{background:#b64f31;bottom:7px;height:2px}.header-actions{margin-left:auto}.search-trigger,.menu-trigger{border:0;background:transparent;color:#233c55;font:bold 13px Arial,sans-serif;padding:11px 0 11px 14px}.search-trigger:hover,.menu-trigger:hover{color:#b04a28;background:transparent}.menu-trigger{display:none}.mobile-nav[hidden]{display:none!important}
/* Utility classes for new homepage */
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}.editorial-home{padding-top:33px;padding-bottom:68px}.small-label,.section-label{display:block;font-size:11px;letter-spacing:.045em;color:#64727d;font-weight:700;text-transform:uppercase}.home-intro{display:grid;grid-template-columns:minmax(0,1.62fr) minmax(250px,1fr);gap:56px;padding:25px 0 36px}.intro-main{padding:8px 0 0}.intro-main h1{font-size:clamp(36px,4.25vw,54px);line-height:1.16;letter-spacing:-.045em;margin:18px 0 17px}.intro-main h1 span{color:#485d70;font-weight:400}.intro-main p{font-size:16px;line-height:1.75;color:#3d4e5b;max-width:590px;margin-bottom:24px}.intro-links{display:flex;flex-wrap:wrap;gap:13px 24px;align-items:center}.intro-links a{font-weight:700;font-size:13px;border-bottom:1px solid #8796a3;padding-bottom:3px}.intro-links a:first-child{color:#b04a28;border-color:#b04a28}.find-panel{border-left:1px solid #d5dadc;padding-left:30px}.find-panel h2{font:700 21px Arial,sans-serif;margin:0 0 16px}.inline-search{display:flex;height:42px;border:1px solid #9daab4;background:#fff}.inline-search input{width:100%;min-width:0;padding:0 12px;border:0;outline-color:#264a6b;font-size:13px}.inline-search button{border:0;background:#23415e;color:#fff;padding:0 16px;font-size:12px;font-weight:700}.find-panel>p{font-weight:700;color:#6a7177;font-size:11px;text-transform:uppercase;letter-spacing:.05em;margin:25px 0 7px}.find-panel ul{padding:0;margin:0;list-style:none}.find-panel li{border-bottom:1px solid #e1e5e7}.find-panel li a{display:flex;justify-content:space-between;padding:8px 0;font-size:13px;font-weight:700}.find-panel li span{font-weight:normal;color:#6d808d}.subject-bar{background:#eef2f4;border-block:1px solid #d5dfe5;padding:12px 17px;display:flex;flex-wrap:wrap;align-items:center;gap:8px 24px;font-size:12px}.subject-bar>span{color:#66747f;font-weight:700}.subject-bar a{font-weight:700;color:#213f5b}
/* Main story and recent list */
.home-feature{display:grid;grid-template-columns:minmax(0,1.62fr) minmax(260px,1fr);gap:56px;padding:47px 0 50px;border-bottom:1px solid #ccd5da}.feature-main h2{font-size:33px;line-height:1.2;letter-spacing:-.025em;max-width:650px;margin:13px 0 12px}.feature-main>p{color:#566572;font-size:14px;max-width:590px;margin-bottom:23px}.plain-link{font-size:13px;font-weight:700;color:#1d517a;border-bottom:1px solid #1d517a;padding:0 0 2px}.worked-example{border:1px solid #d7dde0;border-left:4px solid #c85c38;background:#fafafa;margin-bottom:19px;padding:21px 23px}.example-title{font-size:11px;text-transform:uppercase;font-weight:700;color:#6c747b;letter-spacing:.05em}.example-calc{display:flex;justify-content:space-between;align-items:center;gap:12px;margin:22px 0 15px}.example-calc>span{font:25px Georgia,serif;color:#64717e}.example-calc>div{flex:1}.example-calc small{display:block;font-size:11px;color:#68737a;margin-bottom:5px}.example-calc strong{display:block;font:700 32px/1.1 Arial,sans-serif;letter-spacing:-.04em;color:#223a53}.example-calc .answer strong{color:#a84728}.worked-example>p{font-size:12px;line-height:1.6;color:#57626b;margin:0}.feature-aside h2{font:bold 18px Arial,sans-serif;border-bottom:2px solid #233f58;padding-bottom:12px;margin:0}.recent-item{display:block;border-bottom:1px solid #dfe3e5;padding:15px 0 13px}.recent-item small{display:block;color:#6e767d;font-size:10px;margin-bottom:6px}.recent-item strong{font:700 15px/1.45 Arial,sans-serif;display:block}.feature-aside>.plain-link{display:inline-block;margin-top:19px}
/* Article archive, editorial rows */
.home-library,.topic-overview{padding:47px 0 25px}.home-heading{display:flex;justify-content:space-between;align-items:end;gap:20px;margin:0 0 19px}.home-heading h2{font:bold 28px/1.2 Arial,sans-serif;margin:7px 0 0}.home-heading>a{font-weight:700;font-size:12px;color:#245579;white-space:nowrap}.library-layout{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(240px,1fr);gap:54px}.article-index{border-top:2px solid #233d56}.index-entry{display:grid;grid-template-columns:33px 1fr 18px;gap:18px;padding:16px 3px 15px 0;border-bottom:1px solid #e0e4e5}.index-no{font:20px/1.5 Georgia,serif;color:#929ba2}.index-detail small{display:block;font-size:11px;color:#6c7379;margin-bottom:5px}.index-detail strong{font:bold 16px/1.35 Arial,sans-serif;display:block;margin-bottom:5px}.index-desc{display:block;color:#6f787e;font-size:12px;line-height:1.55}.index-entry .arrow{color:#8594a0}.library-aside{border-top:2px solid #233d56;padding-top:17px}.library-aside h3{font:bold 18px Arial,sans-serif;margin:0 0 9px}.library-aside p{font:14px/1.7 Georgia,serif;color:#515e66;margin-bottom:26px}.aside-topic{background:#f4f6f6;padding:18px 20px}.aside-topic b{font-size:12px;display:block;margin-bottom:10px}.aside-topic a{display:block;padding:11px 0;border-bottom:1px solid #dfe3e5;font-size:13px;line-height:1.4}.aside-topic a:last-child{border:0;padding-bottom:0}
/* Themes: text lists rather than symmetric colorful cards */
.topic-overview{border-top:1px solid #cbd3d8;margin-top:30px;padding-bottom:52px}.topic-columns{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:29px}.topic-column{border-top:2px solid #283e52;padding-top:16px}.topic-column h3{font:bold 19px Arial,sans-serif;margin:0 0 8px}.topic-column ul{list-style:none;padding:0;margin:0}.topic-column li{border-bottom:1px solid #e0e4e5;font-size:13px;line-height:1.5}.topic-column li a{display:block;padding:11px 0}.topic-all{display:inline-block;margin-top:15px;color:#245579;font-size:12px;font-weight:700}
.utility-section{border-top:3px solid #284560;background:#f1f4f5;display:grid;grid-template-columns:1fr 1.4fr;gap:50px;padding:26px 31px 29px}.utility-section h2{font:bold 26px Arial,sans-serif;margin:8px 0 10px}.utility-section>div>p{color:#66747d;font-size:13px;line-height:1.65;max-width:390px}.utility-section ul{list-style:none;padding:0;margin:0}.utility-section li{border-bottom:1px solid #d3dbdf}.utility-section li:first-child{border-top:1px solid #d3dbdf}.utility-section li a{display:grid;grid-template-columns:1fr 1.05fr 18px;gap:15px;padding:13px 0;align-items:center;font-size:13px}.utility-section li span{color:#626f79;font-size:12px}.utility-section li em{font-style:normal;color:#9c4427}.end-note{margin-top:38px;font:italic 16px/1.65 Georgia,serif;color:#5d6770;max-width:680px}.end-note a{border-bottom:1px solid #9da7ac}
/* Common subpage layout */
.archive-page,.directory-page,.search-page,.content-page,.standard-page{padding-top:43px}.archive-top,.directory-intro{max-width:760px;margin-bottom:38px}.archive-top h1,.directory-intro h1{font:bold clamp(34px,4.1vw,51px)/1.12 Arial,sans-serif;letter-spacing:-.04em;margin:10px 0 11px}.archive-top p,.directory-intro p{font:15px/1.7 Arial,sans-serif;color:#627079}.archive-top .eyebrow,.directory-intro .eyebrow,.article-header .eyebrow,.standard-note .eyebrow,.imported-page .eyebrow{font-size:11px;color:#62717c;letter-spacing:.04em}.archive-controls{border-top:2px solid #273f55;border-bottom:1px solid #d3dce0;padding:13px 0}.filter-btn{background:#fff;border:1px solid #b7c3ca;border-radius:3px;padding:7px 12px;font-size:12px;color:#2f4555}.filter-btn.selected{background:#24435f;color:white;border-color:#24435f}.archive-list{border-top:0}.archive-list .post-entry,.reading-list .post-entry,.related-posts .post-entry,.search-page-results .post-entry{border-bottom:1px solid #dbe1e4;padding:18px 0;grid-template-columns:175px 1fr 25px;gap:6px 18px}.post-meta-label,.archive-list .post-meta-label{font-size:11px;color:#6e7881;letter-spacing:0;text-transform:none}.archive-list .post-entry-title,.post-entry-title{font:bold 19px/1.38 Arial,sans-serif;letter-spacing:-.012em}.archive-list .post-entry-summary,.post-entry-summary{color:#6e767d;font:12px/1.6 Arial,sans-serif}.archive-list .post-entry-arrow,.post-entry-arrow{color:#617c8c}.directory-list{border-top:2px solid #263e54}.directory-row{padding:19px 0;border-bottom:1px solid #e0e3e5}.directory-row b{font:700 19px/1.35 Arial,sans-serif}.dir-counter{color:#8997a0}.dir-period{color:#b04a28}
/* Long-form pages: calm type, compact body, clear lesson examples */
.article-page{padding-top:30px}.breadcrumb,.breadcrumbs{color:#777f85;font-size:12px}.article-layout{grid-template-columns:minmax(0,730px) minmax(170px,265px);gap:70px}.article-header h1{font:700 clamp(32px,3.55vw,48px)/1.17 Arial,sans-serif;letter-spacing:-.035em;margin-top:12px;margin-bottom:19px}.article-header .article-intro,.article-header>p{font:16px/1.8 Arial,sans-serif;color:#485f6a}.article-meta,.article-meta time{font-size:11px;color:#707b83}.reading-content{font-size:16px}.reading-content p{font:16px/1.8 Arial,sans-serif;color:#293d49}.reading-content h2{font:700 25px/1.35 Arial,sans-serif;letter-spacing:-.02em;margin:37px 0 14px}.reading-content h3{font:700 19px/1.35 Arial,sans-serif}.reading-content .equation,.imported-page .equation{border:1px solid #d4dde2;border-left:3px solid #b45635;background:#f5f7f8;color:#223a50;font:19px/1.8 Georgia,serif;padding:19px 24px}.reading-content .tip,.reading-content .worked{background:#f7f7f4;border:1px solid #e4e5df;padding:19px 24px}.reading-content details{border-color:#d4dae0}.article-rail .rail-nav{border-top:2px solid #30485d;padding-top:12px}.article-rail .mini-link{font:13px/1.5 Arial,sans-serif}.related-posts{margin-top:49px;border-top:1px solid #dbe1e4;padding-top:22px}.related-posts h2{font:bold 22px Arial,sans-serif}.related-posts .section-heading{margin-bottom:15px}.related-posts .section-spacing{margin-top:0}.article-rail .rail-card{display:none}
.imported-page h1{font:700 clamp(30px,3.5vw,48px)/1.2 Arial,sans-serif;letter-spacing:-.03em}.imported-page h2{font:700 25px/1.35 Arial,sans-serif;letter-spacing:-.02em;margin:32px 0 12px}.imported-page h3{font:bold 19px/1.4 Arial,sans-serif}.imported-page p,.imported-page .article p{font:15px/1.8 Arial,sans-serif;color:#354a57}.imported-page .lead{font:17px/1.65 Arial,sans-serif;color:#5d6973}.imported-page aside{border-top:2px solid #29465f}.imported-page .article-wrap,.imported-page .content-shell{gap:45px}.imported-page .tool-grid{margin-top:24px}.imported-page .field label{font-size:12px}.imported-page .field input,.imported-page .field select{border:1px solid #a7b5bf}.imported-page .tool>button{background:#23415e}.imported-page .result{background:#f3f5f6;border-color:#23415e;font:17px/1.6 Arial,sans-serif}.search-dialog-inner label{font:700 24px Arial,sans-serif}.search-dialog-inner .eyebrow{color:#6e7881}.search-all{color:#1d517a}
/* Low-key, content-focused footer */
.site-footer{background:#f1f3f4;border-top:2px solid #263f56;color:#283c4c;padding:35px 0 15px;margin-top:25px}.editorial-footer .footer-content{display:grid;grid-template-columns:2fr 1fr 1fr;gap:40px;border-bottom:1px solid #d4dce0;padding-bottom:33px}.footer-brand{font:bold 23px Arial,sans-serif;letter-spacing:-.035em}.footer-content p{color:#62717b;font-size:12px;line-height:1.65;max-width:350px;margin:10px 0 0}.footer-nav{display:flex;flex-direction:column;align-items:flex-start;gap:7px}.footer-nav strong{font-size:12px;margin-bottom:4px}.footer-nav a{font-size:12px;color:#576c7b}.footer-legal{display:flex;justify-content:space-between;gap:17px;align-items:center;padding-top:16px;color:#62717b;font-size:11px}.footer-legal>div{display:flex;gap:17px;flex-wrap:wrap}
@media(max-width:930px){.container{width:calc(100% - 42px)}.desktop-nav{gap:18px}.masthead-tag{display:none}.home-intro,.home-feature{gap:27px}.library-layout{gap:30px}.topic-columns{gap:17px}.article-layout{gap:30px;grid-template-columns:minmax(0,1fr) 210px}}
@media(max-width:720px){.container{width:calc(100% - 32px)}.masthead-main{min-height:79px}.masthead-top{height:28px;font-size:10px}.site-header .brand-text{font-size:30px}.site-header .brand-text small{font-size:9px;margin-top:6px}.navigation-inner{min-height:43px}.desktop-nav{display:none}.menu-trigger{display:inline-block}.header-actions{margin-left:auto;display:flex;gap:18px}.search-trigger,.menu-trigger{padding:12px 0;font-size:12px}.mobile-nav:not([hidden]){display:flex;flex-direction:column;padding:5px 16px 15px;box-shadow:0 10px 24px #00000018;background:white}.mobile-nav .nav-link{font-size:13px;border-bottom:1px solid #e5eaed;padding:10px 0}.editorial-home{padding-top:15px}.home-intro,.home-feature,.library-layout,.utility-section{grid-template-columns:1fr;gap:26px}.home-intro{padding:16px 0 24px}.intro-main h1{font-size:clamp(34px,8vw,47px)}.intro-main p{font-size:14px}.find-panel{border-left:0;border-top:1px solid #d9dfe2;padding:20px 0 0}.subject-bar{gap:5px 14px;padding:10px 12px}.home-feature{padding-top:30px}.feature-main h2{font-size:27px}.feature-aside{padding-top:5px}.home-library,.topic-overview{padding-top:32px}.home-heading{align-items:center}.home-heading h2{font-size:23px}.home-heading>a{white-space:normal;text-align:right;font-size:11px}.topic-columns{grid-template-columns:1fr;gap:28px}.topic-column ul{display:grid;grid-template-columns:1fr 1fr;gap:0 18px}.utility-section{padding:21px}.utility-section li a{grid-template-columns:1fr 1fr 16px;gap:10px}.editorial-footer .footer-content{grid-template-columns:1fr 1fr;gap:26px}.editorial-footer .footer-content>div:first-child{grid-column:1/-1}.footer-legal{display:block}.footer-legal>div{margin-top:9px;gap:5px 14px}.archive-page,.directory-page,.content-page,.standard-page{padding-top:29px}.archive-top h1,.directory-intro h1{font-size:36px}.archive-list .post-entry,.search-page-results .post-entry,.related-posts .post-entry{grid-template-columns:1fr 20px;gap:5px 12px}.archive-list .post-meta-label,.archive-list .post-entry-title,.archive-list .post-entry-summary{grid-column:1}.archive-list .post-entry-arrow{grid-column:2;grid-row:1/4}.article-layout{display:block}.article-rail{display:none}.article-header h1{font-size:34px}.reading-content h2{font-size:23px}.imported-page .article-wrap,.imported-page .content-shell{display:block}.imported-page h1{font-size:35px}.imported-page aside{display:none}.imported-page .tool-grid{grid-template-columns:1fr}.reading-content .equation,.imported-page .equation{font-size:17px;padding:15px 18px}}
@media(max-width:420px){.subject-bar{gap:8px 11px}.subject-bar a{font-size:11px}.example-calc{gap:5px}.example-calc strong{font-size:27px}.example-calc small{font-size:10px}.topic-column ul{display:block}.utility-section li a{grid-template-columns:1fr 15px;gap:5px}.utility-section li span{grid-column:1;grid-row:2}.utility-section li em{grid-column:2;grid-row:1/3}.index-entry{gap:12px;grid-template-columns:27px 1fr 13px}}
@media print{.site-header,.site-footer,.find-panel,.feature-aside,.library-aside{display:none!important}.editorial-home,.article-page{padding-top:0}}