/* Approved modern presentation. Content and learning state are shared. */
html:root[data-theme=dark]{--paper:#08090b;--surface:#17191d;--tint:#202329;--ink:#f5f6f8;--muted:#b0b5c0;--rule:#333842;--crimson:#99bbff;--green:#a5d6b6;--theme-strong:#202838}
html:root[data-theme=dark] .container{max-width:1180px}
html:root[data-theme=dark] .site-header{position:relative;background:#08090b;border:0}
html:root[data-theme=dark] .header-inner{min-height:84px;gap:24px}
html:root[data-theme=dark] .brand{font-size:18px;font-weight:650;letter-spacing:-.02em}
html:root[data-theme=dark] .brand-subtitle{font-size:14px;font-weight:400;color:var(--muted);margin-top:4px}
html:root[data-theme=dark] .brand-flag{width:28px;height:40px}
html:root[data-theme=dark] .main-navigation{gap:20px;font-size:14px}
html:root[data-theme=dark] .main-navigation>a{border:0;color:var(--muted)}
html:root[data-theme=dark] .main-navigation>a:is(:hover,[aria-current]){color:var(--ink)}
html:root[data-theme=dark] .site-menu-toggle{padding:8px;background:transparent}
html:root[data-theme=dark] .theme-toggle{background:transparent;border-color:transparent}
html:root[data-theme=dark][data-prelaunch] .preview-strip{background:transparent;border:0}
html:root[data-theme=dark][data-prelaunch] .preview-inner{min-height:0;justify-content:flex-end;padding-block:0}
html:root[data-theme=dark][data-prelaunch] .preview-inner strong{display:inline-block;background:#902c42;color:#fff;font-size:18px;border-radius:7px;padding:5px 12px}
html:root[data-theme=dark] .button{min-height:44px;border-radius:999px;padding:.7rem 1.2rem;font-size:max(.875rem,14px);font-weight:600}
html:root[data-theme=dark] .button-primary{background:#dce8ff;color:#101928;border:1px solid #dce8ff}
html:root[data-theme=dark] .button-primary:hover:not(:disabled){background:#c1d6fc}
html:root[data-theme=dark] .button-secondary{background:#202329;border-color:#424854;color:var(--ink)}
html:root[data-theme=dark] a:focus-visible,html:root[data-theme=dark] button:focus-visible{outline-color:#99bbff}
html:root[data-theme=dark] :is(.site-menu,.question-feedback-dialog){background:#17191d;border-color:#424854;color:var(--ink);box-shadow:0 18px 80px #0008}
html:root[data-theme=dark] .site-menu a[aria-current=page]{background:#252d3b;border-color:#99bbff}
html:root[data-theme=dark] .site-menu :is(a,button):hover{background:#252d3b}
html:root[data-theme=dark] .site-footer{background:transparent;border-top:1px solid var(--rule);font-size:14px;padding-block:24px}
html:root[data-theme=dark] .footer-inner{gap:16px}
html:root[data-theme=dark] .handbook-banner{border:0;padding:0;background:transparent;width:max-content;margin:16px auto 0;color:#b0b5c0}
html:root[data-theme=dark] .handbook-banner strong{font-size:14px;font-weight:550}
html:root[data-theme=dark] .home-intro{display:flex;flex-direction:column;align-items:center;gap:28px;padding:18px 0 32px;text-align:center}
html:root[data-theme=dark] .home-intro-copy{max-width:800px;width:100%}
html:root[data-theme=dark] .home-intro .eyebrow{font-size:14px;color:var(--muted);margin:0 0 12px;text-transform:none;letter-spacing:0}
html:root[data-theme=dark] .home-intro h1{font-size:clamp(2.3rem,5vw,4.2rem);line-height:1.06;font-weight:650;max-width:18ch;margin:0 auto 18px;letter-spacing:-.045em}
html:root[data-theme=dark] .home-intro .lead{font-size:18px;line-height:1.6;margin:0 auto;color:var(--muted)}
html:root[data-theme=dark] .home-actions{justify-content:center;gap:12px;margin-top:22px}
html:root[data-theme=dark] .home-actions [data-features-toggle]{order:-1}
html:root[data-theme=dark] .home-signup{font-size:14px;margin-top:4px;color:#99bbff}
html:root[data-theme=dark] .home-demo{width:min(100%,540px);padding:0;text-align:left}
html:root[data-theme=dark] .sample-heading{margin:0 0 12px}
html:root[data-theme=dark] .sample-heading h2{font-size:14px;color:var(--muted);font-weight:500}
html:root[data-theme=dark] .sample-stack{margin:0 0 16px}
html:root[data-theme=dark] .sample-stack::before{background:#111318;border-color:#333842;transform:translateY(9px) scale(.95);border-radius:18px}
html:root[data-theme=dark] .sample-stack::after{background:#17191e;border-color:#333842;transform:translateY(5px) scale(.977);border-radius:18px}
html:root[data-theme=dark] .sample-card{min-height:var(--sample-height,220px);padding:22px 24px;background:linear-gradient(135deg,#202329,#17191d);border:1px solid #424854;border-radius:18px;box-shadow:0 12px 38px #0003}
html:root[data-theme=dark] .sample-question{font-size:24px;line-height:1.35;font-weight:550;min-height:2.7em}
html:root[data-theme=dark] .sample-card .eyebrow{color:#99bbff;margin-bottom:12px}
html:root[data-theme=dark] .sample-answer{border-top-color:#333842;padding-top:12px;margin-top:14px}
html:root[data-theme=dark] .sample-controls{justify-content:space-between;gap:12px}
html:root[data-theme=dark] .home-features{padding:8px 0 26px}
html:root[data-theme=dark] .home-feature-grid{gap:24px}
html:root[data-theme=dark] .home-feature-grid>div{border:0;padding:0}
html:root[data-theme=dark] .home-feature-grid h3{font-size:16px;margin:12px 0 6px}
html:root[data-theme=dark] .home-feature-grid p{font-size:14px;line-height:1.6}
html:root[data-theme=dark] .home-feature-grid .icon{color:#b0b5c0;width:24px;height:24px}
html:root[data-theme=dark] .curriculum{position:relative;margin:4px 0 0;padding:32px 0;isolation:isolate}
html:root[data-theme=dark] .curriculum::before{content:'';position:absolute;inset:0 calc((1180px - 100vw)/2);background:#111318;z-index:-1}
html:root[data-theme=dark] .curriculum .section-heading h2{font-size:25px;letter-spacing:-.03em}
html:root[data-theme=dark] .curriculum .section-heading p{font-size:14px;margin-top:6px}
html:root[data-theme=dark] .curriculum-entry{margin:20px 0 24px;gap:20px}
html:root[data-theme=dark] .sample-pointer p{background:#202838;border:0;padding:10px 14px}
html:root[data-theme=dark] .sample-pointer strong{font-size:14px;color:#dce8ff}
html:root[data-theme=dark] .sample-pointer span{font-size:14px;color:var(--muted)}
html:root[data-theme=dark] .intro-link{border:1px dashed #515866;border-radius:10px;font-size:14px;padding:10px 14px}
.modern-chapter-browser{display:grid;grid-template-columns:290px minmax(0,1fr);gap:32px;align-items:start}
.modern-chapter-tabs{display:grid;gap:6px}
.modern-chapter-tabs button{display:flex;align-items:center;gap:14px;min-height:60px;text-align:left;padding:14px;border:1px solid transparent;border-radius:12px;background:transparent;color:#b0b5c0;font-size:16px;line-height:1.4;cursor:pointer}
.modern-chapter-tabs button[aria-selected=true]{background:#242831;border-color:#424854;color:#f5f6f8}
.modern-chapter-tabs button:hover{background:#202329;color:#f5f6f8}
.modern-chapter-number{font-size:14px;color:#99bbff;flex:none}
.modern-chapter-panels{min-width:0}
.modern-chapter-panels h3{font-size:24px;margin:0 0 6px;letter-spacing:-.03em}
.modern-chapter-description{color:#b0b5c0;font-size:14px;margin-bottom:20px}
html:root[data-theme=dark] .modern-chapter-panels .chapter-content{padding:0;border:0}
html:root[data-theme=dark] .modern-chapter-panels .unit-grid{display:block}
html:root[data-theme=dark] .modern-chapter-panels .unit-card{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:5px 20px;position:relative;padding:20px 0;border:0;border-top:1px solid #333842;border-radius:0;background:transparent;color:#f5f6f8;margin:0}
html:root[data-theme=dark] .modern-chapter-panels .card-top{grid-column:1/-1;justify-content:flex-start;gap:12px;margin:0}
html:root[data-theme=dark] .modern-chapter-panels .topic-icon{display:none}
html:root[data-theme=dark] .modern-chapter-panels .unit-card h4{grid-column:1;margin:0;font-size:18px}
html:root[data-theme=dark] .modern-chapter-panels .unit-card>p{grid-column:1;margin:4px 0;color:#b0b5c0}
html:root[data-theme=dark] .modern-chapter-panels .card-meta{grid-column:1;justify-content:flex-start;gap:12px;font-size:14px}
html:root[data-theme=dark] .modern-chapter-panels .card-bottom{grid-column:2;grid-row:2/5;border:0;padding:0;align-self:center;margin:0}
html:root[data-theme=dark] .modern-chapter-panels .card-bottom>span{display:none}
html:root[data-theme=dark] .modern-chapter-panels .outline-link{background:#242831;border-radius:50%;width:44px;height:44px;display:grid;place-items:center}
html:root[data-theme=dark] .chapter{background:transparent;border:0;border-bottom:1px solid #333842;border-radius:0}
html:root[data-theme=dark] .chapter>summary{padding:16px 0}
html:root[data-theme=dark] .chapter-content{padding:16px 0}
html:root[data-theme=dark] .unit-card{background:#17191d;border-color:#333842;border-radius:12px}
html:root[data-theme=dark] .topic-icon,html:root[data-theme=dark] .hub-emblem{background:#202838;border-color:#424854;color:#99bbff}
html:root[data-theme=dark] .home-faq{border:0;padding:28px 0 36px}
html:root[data-theme=dark] .home-faq-grid{gap:28px}
html:root[data-theme=dark] .home-faq h2{font-size:25px}
html:root[data-theme=dark] .home-faq h3{font-size:16px}
/* Reading is a continuous column. The sidebar and activity bar carry navigation. */
html:root[data-theme=dark] .breadcrumbs{font-size:14px;padding-top:18px;line-height:1.6}
html:root[data-theme=dark] .lesson-heading{padding:18px 0 12px;margin:0}
html:root[data-theme=dark] .lesson-heading h1{font-size:clamp(2rem,3.4vw,2.8rem);max-width:30ch;margin-bottom:12px}
html:root[data-theme=dark] .lesson-heading .lead{font-size:16px;line-height:1.6;color:#b0b5c0}
html:root[data-theme=dark] .study-layout{grid-template-columns:215px minmax(0,1fr);gap:40px;margin-top:20px}
html:root[data-theme=dark] .study-layout.single-lesson{grid-template-columns:minmax(0,1fr)}
html:root[data-theme=dark] .lesson-contents{border:0;padding:0;font-size:14px}
html:root[data-theme=dark] .lesson-contents nav{background:transparent;border:0;padding:0}
html:root[data-theme=dark] .lesson-contents a{border:0;border-radius:8px;padding:10px 12px;line-height:1.5}
html:root[data-theme=dark] .lesson-contents a[aria-current=page]{background:#202838;color:#dce8ff;font-weight:600;border:0}
html:root[data-theme=dark] .lesson-contents h2{font-size:16px}
html:root[data-theme=dark] .lesson-toolbar{position:sticky;top:0;z-index:10;background:#08090bf5;border:0;border-bottom:1px solid #333842;padding:12px 0;margin-bottom:12px;gap:16px}
html:root[data-theme=dark] .lesson-steps{display:flex;position:relative;isolation:isolate;gap:0;padding:4px;background:#17191d;border:1px solid #333842;border-radius:12px}
html:root[data-theme=dark] .lesson-steps a{border:0!important;border-radius:8px;min-height:44px;padding:10px 16px;background:transparent!important;color:#b0b5c0;font-size:14px;line-height:1.4;display:flex;align-items:center;justify-content:center}
html:root[data-theme=dark] .lesson-steps a[aria-current=step]{color:#f5f6f8}
html:root[data-theme=dark] .lesson-steps a>span{display:none}
.modern-stage-pill{display:none;position:absolute;top:0;left:0;pointer-events:none;background:#353b46;border-radius:8px;z-index:-1}
html:root[data-theme=dark] .modern-stage-pill{display:block}
html:root[data-theme=dark] .reading-preference{font-size:14px;gap:8px}
html:root[data-theme=dark] .reading-preference select{padding:8px 10px;border-radius:8px}
html:root[data-theme=dark] .lesson-prose{max-width:70ch;line-height:1.6}
html:root[data-theme=dark] .lesson-section>h2{font-size:calc(1.3rem * var(--study-scale));font-weight:600;letter-spacing:-.02em;margin:0 0 12px}
html:root[data-theme=dark] .lesson-prose>.lesson-section+.lesson-section{border-top:1px solid #333842;padding-top:24px;margin-top:24px}
html:root[data-theme=dark] .reading-blocks>h3{font-size:1.05em;margin-top:20px}
html:root[data-theme=dark] .lesson-prose :is(p,ul,ol){margin-bottom:1em}
html:root[data-theme=dark] .lesson-definition{background:transparent;border-left:2px solid #99bbff;padding:0 0 0 16px;margin:20px 0}
html:root[data-theme=dark] .lesson-background{border:1px solid #333842;border-radius:10px;background:#111318}
html:root[data-theme=dark] .lesson-background>summary{padding:14px 16px;font-size:16px}
html:root[data-theme=dark] .learning-timeline{background:transparent;border:0;border-top:1px solid #333842;padding:24px 0;margin:24px 0}
html:root[data-theme=dark] .lesson-visual{background:transparent;border:0;border-radius:0;padding:12px 0}
html:root[data-theme=dark] .lesson-visual figcaption{font:600 1.15em/1.4 'Inter Variable',sans-serif}
html:root[data-theme=dark] .recall-section{padding-top:12px}
html:root[data-theme=dark] .recall-card{border:1px solid #424854;border-radius:18px;background:linear-gradient(135deg,#202329,#17191d);padding:24px}
html:root[data-theme=dark] .recall-card h3{font-size:calc(1.4rem * var(--study-scale));line-height:1.4;min-height:2.4em}
html:root[data-theme=dark] .recall-answer p:last-child{font-size:calc(1rem * var(--study-scale));line-height:1.6}
html:root[data-theme=dark] .recall-rating .button{flex:1}
html:root[data-theme=dark] .lesson-check-entry{border:0;border-top:1px solid #333842;background:transparent;padding:22px 0;margin:24px 0}
html:root[data-theme=dark] .subsection-pagination{border-top:1px solid #333842;padding-top:20px;margin-top:28px}
html:root[data-theme=dark] body[data-modern-lesson-stage=read] .lesson-prose[data-lesson-id]>.recall-section{display:none}
html:root[data-theme=dark] body[data-modern-lesson-stage=cards] .lesson-prose[data-lesson-id]>:not(.recall-section){display:none}
html:root[data-theme=dark] body[data-modern-lesson-stage=cards] #reading>.subsection-pagination{display:none}
/* Practice, search, account and supporting pages share the modern application surfaces. */
html:root[data-theme=dark] :is(.practice-heading,.hub-heading){padding-block:20px;margin-bottom:16px;border:0}
html:root[data-theme=dark] :is(.practice-heading,.hub-heading) h1{font-size:clamp(2rem,3.4vw,2.8rem)}
html:root[data-theme=dark] :is(.question-panel,.setup-panel,.results-panel,.exercise-panel){border:0;border-radius:0;background:transparent;box-shadow:none;padding:20px 0}
html:root[data-theme=dark] .practice-layout{gap:36px}
html:root[data-theme=dark] .practice-sidebar{background:#111318;border:1px solid #333842;border-radius:14px;padding:20px}
html:root[data-theme=dark] .question-panel legend{font-size:calc(1.5rem * var(--study-scale));font-weight:550;line-height:1.4;letter-spacing:-.02em}
html:root[data-theme=dark] .answer-option{background:#17191d;border:1px solid #424854;border-radius:12px;padding:15px 18px}
html:root[data-theme=dark] .answer-option:has(input:checked){background:#202c40;border-color:#99bbff}
html:root[data-theme=dark] .answer-feedback{border-radius:12px;padding:20px;line-height:1.6}
html:root[data-theme=dark] .question-grid button{border-radius:8px}
html:root[data-theme=dark] .question-controls{gap:12px;padding-top:12px}
html:root[data-theme=dark] :is(.account-panel,.progress-panel){background:#111318;border:1px solid #333842;border-radius:14px;padding:24px}
html:root[data-theme=dark] :is(input:not([type=checkbox]):not([type=radio]),textarea,select){border-color:#626977;border-radius:9px}
html:root[data-theme=dark] .search-result{background:transparent;border:0;border-bottom:1px solid #333842;border-radius:0;padding:22px 0}
html:root[data-theme=dark] .mock-app h2{font-family:'Inter Variable',sans-serif}
html:root[data-theme=dark] body:not([data-mock-layout=test-centre]) .mock-question-panel{border:0;background:transparent;padding:20px 0}
html:root[data-theme=dark] body:not([data-mock-layout=test-centre]) .mock-options label{border-radius:12px;border-color:#424854;background:#17191d}
html:root[data-theme=dark] body:not([data-mock-layout=test-centre]) .mock-options label:has(input:checked){background:#202c40;border-color:#99bbff}
/* Independent test-centre colours, typography and controls remain authoritative. */
html:root[data-theme=dark] body[data-mock-layout=test-centre] .mock-question-panel{border-radius:0}
:root{--study-scale:1}
html:root[data-reading-size=large]{--study-scale:1.1875}
html:root[data-reading-size=larger]{--study-scale:1.375}
html:root .lesson-prose{font-size:calc(1rem * var(--study-scale));line-height:1.6}
[hidden]{display:none!important}
@media(prefers-reduced-motion:no-preference){
 .modern-stage-pill{transition:width 180ms ease,transform 180ms ease,height 180ms ease}
 html:root[data-theme=dark] :is(button,.button,.main-navigation a){transition:background-color 140ms ease,color 140ms ease,border-color 140ms ease}
}
@media(max-width:1230px){html:root[data-theme=dark] .curriculum::before{inset:0 -24px}}
@media(max-width:900px){
 html:root[data-theme=dark] .header-inner{gap:16px;flex-wrap:wrap;padding-block:14px}
 html:root[data-theme=dark] .study-layout{grid-template-columns:minmax(0,1fr);gap:16px}
 html:root[data-theme=dark] .lesson-menu{border:1px solid #333842;border-radius:10px;padding:8px 12px}
 html:root[data-theme=dark] .home-feature-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
 html:root[data-theme=dark] .lesson-toolbar{flex-wrap:wrap}
 html:root[data-theme=dark] .home-faq-grid{grid-template-columns:1fr;gap:18px}
}
@media(max-width:600px){
 html:root[data-theme=dark] .container{width:calc(100% - 32px)}
 html:root[data-theme=dark] .header-inner{display:flex;gap:12px}
 html:root[data-theme=dark] .brand{font-size:16px;gap:10px;min-width:0}
 html:root[data-theme=dark] .brand>span{min-width:0}
 html:root[data-theme=dark] .brand-subtitle{font-size:14px}
 html:root[data-theme=dark] .main-navigation{gap:16px;justify-content:space-between;width:100%;flex-wrap:wrap}
 html:root[data-theme=dark] .preview-inner{padding-bottom:8px}
 html:root[data-theme=dark] .home-intro{gap:24px;padding:14px 0 28px}
 html:root[data-theme=dark] .home-intro h1{font-size:36px;max-width:17ch}
 html:root[data-theme=dark] .home-intro .lead{font-size:16px}
 html:root[data-theme=dark] .home-actions{flex-direction:row;flex-wrap:wrap;gap:10px}
 html:root[data-theme=dark] .home-actions .button{width:auto;flex:1 1 155px}
 html:root[data-theme=dark] .sample-card{padding:18px}
 html:root[data-theme=dark] .sample-question{font-size:22px}
 html:root[data-theme=dark] .curriculum{padding-block:24px}
 html:root[data-theme=dark] .curriculum::before{inset:0 -16px}
 html:root[data-theme=dark] .curriculum .section-heading{align-items:start;gap:12px}
 html:root[data-theme=dark] .curriculum .section-heading h2{font-size:23px}
 html:root[data-theme=dark] .curriculum-entry{flex-direction:column;gap:16px}
 html:root[data-theme=dark] .curriculum-entry .intro-link{order:0}
 html:root[data-theme=dark] .chapter>summary{gap:12px}
 html:root[data-theme=dark] .chapter-count{display:none}
 html:root[data-theme=dark] .lesson-steps{width:100%}
 html:root[data-theme=dark] .lesson-steps a{flex:1;padding:10px 9px;white-space:normal}
 html:root[data-theme=dark] .reading-preference{margin-left:auto}
 html:root[data-theme=dark] .recall-card{padding:18px}
 html:root[data-theme=dark] .recall-card h3{min-height:3em}
 html:root[data-theme=dark] .practice-layout{gap:20px}
 html:root[data-theme=dark] .question-panel legend{font-size:calc(1.3rem * var(--study-scale))}
 html:root[data-theme=dark] .footer-inner{flex-wrap:wrap}
}

.modern-read-next{display:none}html:root[data-theme=dark] .modern-read-next{display:inline-flex}
html:root[data-theme=dark]:not([data-signed-in]) .modern-chapter-panels .unit-card.free-sample{background:transparent;border-color:#333842}
html:root[data-theme=dark] .modern-chapter-panels .card-meta{padding-bottom:0;display:flex;flex-wrap:wrap}
html:root[data-theme=dark] .lesson-steps>.modern-stage-pill{border:0;border-radius:8px;display:block}