:root{--ui-ink:#192f49;--ui-muted:#5a6877;--ui-paper:#f7f8fa;--ui-line:#dfe5eb;--ui-yellow:#f8ca4d;--ui-green:#276951;--ui-font:ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif}
html{scroll-padding-top:0}
body{color:var(--ui-ink);background:var(--ui-paper);font-family:var(--ui-font)}
/* clip avoids creating a second scroll container that would disable the sticky header. */
body.questions-container{max-width:1200px;padding:24px;background:var(--ui-paper);overflow-x:clip;overflow-y:visible!important}
.ui-icon{display:inline-block;width:22px;height:22px;flex:none;vertical-align:middle}
a,button,summary,input{ -webkit-tap-highlight-color:transparent }
a:focus-visible,button:focus-visible,summary:focus-visible,input:focus-visible{outline:3px solid #357ac5;outline-offset:4px}
.site-header,.study-hero,.study-benefits,.study-guide-section,.study-faq,.site-footer,.study-subject-switch,.page-heading{font-family:var(--ui-font);box-sizing:border-box}
.site-header a,.study-hero a,.study-guide-section a,.site-footer a,.study-subject-switch a{text-decoration:none}
.site-header.local-header{display:flex;align-items:center;justify-content:space-between;gap:24px;position:sticky;top:0;z-index:70;min-height:84px;padding:16px 24px;margin:0;background:#fff;color:var(--ui-ink);font:500 14px/1.4 var(--ui-font);box-shadow:0 1px 0 var(--ui-line)}
body.questions-container>.site-header{margin:-24px -24px 24px}
.site-brand{display:inline-flex;align-items:center;gap:11px;flex-shrink:0;color:var(--ui-ink);font:800 20px/1.15 var(--ui-font);letter-spacing:-.6px;white-space:nowrap}
.site-brand:hover{color:var(--ui-ink)}
.site-brand-mark{display:grid;place-items:center;width:42px;height:46px;background:var(--ui-ink);border-radius:12px;color:var(--ui-yellow)}
.site-brand-mark .ui-icon{width:26px;height:26px}
.site-brand-dot{padding:0 4px;color:#8c6b16}
.site-brand small,.site-header .site-brand small{display:block;margin:5px 0 0;font:400 11px/1 var(--ui-font);letter-spacing:.45px;color:var(--ui-muted);opacity:1}
.site-desktop-nav{display:flex;align-items:center;gap:22px}
.site-desktop-nav>a,.site-account{color:var(--ui-muted);white-space:nowrap;padding:12px 0}
.site-desktop-nav>a:hover,.site-account:hover{color:var(--ui-ink)}
.site-header-actions{display:flex;gap:19px;align-items:center}
.site-dropdown{position:relative}
.site-dropdown>summary{display:flex;align-items:center;gap:4px;min-height:44px;list-style:none;cursor:pointer;color:var(--ui-ink);font-weight:600}
.site-dropdown>summary .ui-icon{width:17px;height:17px}
.site-dropdown summary::-webkit-details-marker,.site-mobile-menu summary::-webkit-details-marker{display:none}
.site-dropdown[open]>summary>.ui-icon:last-child:not(:only-child){transform:rotate(180deg)}
.site-dropdown.is-current>summary{color:#1d6096}
.site-dropdown-panel{position:absolute;top:calc(100% + 12px);left:-18px;width:310px;max-height:calc(100dvh - 110px);overflow:auto;padding:14px;border:1px solid var(--ui-line);border-radius:14px;background:#fff;box-shadow:0 16px 45px #192f4929}
.site-dropdown-panel>a{display:block;padding:10px 12px;color:var(--ui-ink);border-radius:7px;font-size:14px}
.site-dropdown-panel>a:hover,.site-dropdown-panel>a[aria-current]{background:#edf3f7;color:#1d6096}
.site-nav-label{display:block;padding:16px 12px 6px;font-size:11px;font-weight:700;letter-spacing:1px;text-transform:uppercase;color:var(--ui-muted)}
.site-search>summary{justify-content:center;width:36px}
.site-search>summary .ui-icon{width:21px;height:21px}
.site-search-panel{left:auto;right:-30px;width:360px;padding:20px}
.site-search-panel form{margin:0}
.site-search-panel label{display:block;font-size:14px;font-weight:600;margin-bottom:10px}
.site-search-panel form>div{display:flex;gap:8px}
.site-search-panel input{width:100%;min-width:0;padding:11px;border:1px solid #9dabb8;border-radius:8px;font:16px var(--ui-font)}
.site-search-panel button{padding:10px 14px;border:0;border-radius:8px;background:var(--ui-ink);color:#fff;font:600 14px var(--ui-font);cursor:pointer}
a.site-header-cta{display:flex;align-items:center;justify-content:center;gap:10px;min-height:46px;padding:12px 17px;border-radius:9px;background:var(--ui-yellow);color:var(--ui-ink);font-weight:750;white-space:nowrap}
.site-header-cta .ui-icon{width:18px}
a.site-header-cta:hover,.study-button:hover{background:#ffd975;color:var(--ui-ink)}
.site-mobile-menu{display:none}
.site-skip-link{position:fixed;top:8px;left:8px;z-index:1500;transform:translateY(-150%);padding:12px 18px;background:#fff;color:var(--ui-ink)}
.site-skip-link:focus{transform:none}
.seo-breadcrumbs{font-family:var(--ui-font);font-size:12px;line-height:1.6;margin:0 0 18px;color:var(--ui-muted)}
.seo-breadcrumbs a{color:#4b647e;text-decoration:none}
.seo-breadcrumbs a:hover{text-decoration:underline}
.study-hero{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);align-items:center;gap:48px;padding:32px 10px 44px;margin:0;white-space:normal}
.study-eyebrow{display:flex;align-items:center;gap:8px;margin:0 0 20px;color:var(--ui-muted);font:650 11px/1.5 var(--ui-font);letter-spacing:1.3px;text-transform:uppercase}
.study-eyebrow>span:empty{width:7px;height:7px;border-radius:50%;background:var(--ui-green);box-shadow:0 0 0 4px #e1eee7}
.study-hero h1{margin:0 0 24px;padding:0;color:var(--ui-ink);font:760 clamp(42px,4.7vw,62px)/1.06 var(--ui-font);letter-spacing:-2.8px;white-space:normal!important;overflow-wrap:normal}
.study-hero h1 em{position:relative;display:inline-block;font-style:normal;z-index:0}
.study-hero h1 em:after{content:"";position:absolute;z-index:-1;left:0;right:0;bottom:1px;height:12px;background:var(--ui-yellow);transform:rotate(-1deg)}
.study-lead{max-width:510px;margin:0 0 25px;color:var(--ui-muted);font-size:17px;line-height:1.75}
.study-exam-links{display:grid;gap:2px;margin:-8px 0 20px;font:500 13px/1.5 var(--ui-font);color:var(--ui-muted)}
.study-exam-links>div{display:grid;grid-template-columns:3em repeat(3,max-content);align-items:center;column-gap:14px}
.study-exam-links a{display:inline-flex;align-items:center;min-height:44px;color:#1d6096;text-decoration:underline;text-underline-offset:3px}
.study-actions{display:flex;align-items:center;flex-wrap:wrap;gap:16px}
a.study-button{display:inline-flex;align-items:center;justify-content:center;gap:18px;min-height:54px;padding:14px 23px;border-radius:10px;background:var(--ui-yellow);color:var(--ui-ink);font:750 15px/1.4 var(--ui-font);text-decoration:none;box-shadow:0 3px 0 #cda22930}
.study-secondary{display:inline-flex;align-items:center;gap:7px;min-height:44px;color:var(--ui-ink);font-size:14px;font-weight:650}
.study-secondary .ui-icon{width:17px}
.study-secondary:hover{text-decoration:underline}
.study-reassurance{display:flex;align-items:center;gap:7px;margin:14px 0 26px;color:var(--ui-muted);font-size:12px;line-height:1.5}
.study-reassurance .ui-icon{width:15px;height:15px;color:var(--ui-green)}
.study-stats{display:flex;align-items:flex-start;gap:26px;border-top:1px solid var(--ui-line);padding-top:22px}
.study-stats>div+div{padding-left:25px;border-left:1px solid var(--ui-line)}
.study-stats strong{display:block;font-size:25px;line-height:1.15;font-weight:750;letter-spacing:-.8px;color:var(--ui-ink)}
.study-stats span{display:block;margin-top:6px;max-width:125px;color:var(--ui-muted);font-size:11px;line-height:1.5}
.study-preview{position:relative;padding:14px 12px 0;isolation:isolate}
.study-preview:before{content:"";position:absolute;inset:45px -3px 48px 30px;border-radius:22px;background:#edf0e6;transform:rotate(5deg);z-index:-1}
.study-preview-note{display:flex;align-items:center;gap:7px;width:max-content;max-width:100%;position:relative;margin:0 0 -9px 18px;padding:10px 15px;border-radius:8px;background:var(--ui-yellow);color:var(--ui-ink);font-size:11px;font-weight:700;transform:rotate(-3deg);z-index:1}
.study-preview-note .ui-icon{width:15px;height:15px}
.study-preview-card{padding:29px 25px 18px;background:#fff;border:1px solid #e0e5e9;border-radius:18px;box-shadow:0 15px 45px #192f4910}
.study-preview-top{display:flex;align-items:center;gap:10px;padding-bottom:18px;border-bottom:1px solid var(--ui-line)}
.study-subject-icon{display:grid;place-items:center;width:38px;height:42px;border-radius:10px;background:#edf3f8;color:var(--ui-ink);flex:none}
.study-preview-top strong{display:block;font-size:14px;line-height:1.4}
.study-preview-top div>span{display:block;margin-top:3px;color:var(--ui-muted);font-size:10px}
.study-example-tag{margin-left:auto;padding:4px 6px;border:1px solid var(--ui-line);border-radius:5px;font-size:9px;color:var(--ui-muted);letter-spacing:.7px}
.study-preview-question{margin:22px 0 18px;font-size:17px;font-weight:550;line-height:1.65;color:var(--ui-ink)}
.study-preview-sketch{display:grid;justify-content:center;gap:9px;padding:19px 8px;border-radius:8px;background-color:#f7f9fb;background-image:linear-gradient(#e4eaf080 1px,transparent 1px),linear-gradient(90deg,#e4eaf080 1px,transparent 1px);background-size:20px 20px;color:var(--ui-ink);font:500 18px/1.6 var(--ui-font)}
.study-preview-sketch b{margin:0 10px;color:#7091a7;font-weight:400}
.study-preview-sketch i{display:inline-block;min-width:15px;font-weight:750;font-style:normal;color:#a66a00}
.study-preview-sketch small{color:var(--ui-muted);font-size:12px;text-align:center}
.study-demo-answer{margin-top:17px;border:1px solid #ccd8e2;border-radius:9px;background:#fff}
.study-demo-answer>summary{display:flex;align-items:center;justify-content:center;gap:12px;min-height:45px;padding:9px 13px;list-style:none;font-size:13px;font-weight:700;cursor:pointer;color:var(--ui-ink)}
.study-demo-answer summary::-webkit-details-marker{display:none}
.study-demo-answer>summary .ui-icon{width:17px;height:17px}
.study-demo-answer[open]>summary{border-bottom:1px solid var(--ui-line)}
.study-demo-answer[open]>summary .ui-icon{transform:rotate(180deg)}
.study-demo-answer>div{padding:14px;font-size:13px;line-height:1.6}
.study-demo-answer strong{color:var(--ui-green)}
.study-demo-answer p{margin:6px 0 0}
.study-preview-link{display:flex;align-items:center;justify-content:space-between;margin-top:14px;padding:5px 0;color:var(--ui-muted);font-size:11px}
.study-preview-link .ui-icon{width:17px;height:17px}
.study-preview-link:hover{color:#1d6096}
.study-preview-caption{margin:22px 0 0;text-align:center;color:var(--ui-muted);font-size:11px}
.study-benefits{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:25px;margin:0 0 46px;padding:25px 0;border-top:1px solid var(--ui-line);border-bottom:1px solid var(--ui-line);white-space:normal}
.study-benefits>div{display:flex;align-items:flex-start;gap:13px}
.study-benefits>div>span{flex:none;display:grid;place-items:center;width:34px;height:34px;border-radius:50%;border:1px solid #cad5df;color:#728397;font-size:11px;font-weight:600}
.study-benefits h2{margin:0 0 5px;font:700 14px/1.4 var(--ui-font);color:var(--ui-ink)}
.study-benefits p{margin:0;color:var(--ui-muted);font-size:12px;line-height:1.6}
.study-subject-switch{display:flex;gap:5px;width:max-content;max-width:100%;padding:5px;margin:0 0 20px;border:1px solid var(--ui-line);border-radius:12px;background:#eceff3;scroll-margin-top:100px}
.study-subject-switch>a{display:flex;align-items:center;justify-content:center;gap:8px;min-height:45px;padding:11px 20px;border-radius:8px;color:var(--ui-muted);font-size:14px;font-weight:650;white-space:nowrap}
.study-subject-switch>a[aria-current]{background:#fff;color:var(--ui-ink);box-shadow:0 2px 5px #192f490c}
.study-subject-switch .ui-icon{width:20px;height:20px}
.study-subject-switch span{font-size:11px;font-weight:400}
#practice,#subjects,#part-1,#part-2,#study-guide,#how-to-study{scroll-margin-top:106px}
.math-topics{border:0;background:transparent;padding:0;margin-bottom:26px;box-shadow:none;font-family:var(--ui-font)}
.math-topics-heading{align-items:center;margin-bottom:23px}
.math-topics-heading h2{font:740 28px/1.25 var(--ui-font);letter-spacing:-.8px;white-space:normal}
.math-topics-heading p{font:400 14px/1.6 var(--ui-font);margin-top:7px}
a.math-all-link{padding:10px 13px;border:1px solid var(--ui-line);background:#fff;color:var(--ui-ink);font-size:12px;font-weight:650}
.math-topic-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;align-items:start}
.math-topic-group{border:1px solid var(--ui-line);border-radius:12px;background:#fff}
.math-topic-group summary{gap:9px;min-height:74px;background:#fff;padding:17px 15px;color:var(--ui-ink);font:650 14px/1.5 var(--ui-font);list-style:none}
.math-topic-group summary:after{content:"+";color:#8294a5;font-size:22px;font-weight:400}
.math-topic-group summary::-webkit-details-marker{display:none}
.math-topic-group[open] summary:after{content:"−"}
.math-topic-group summary>span:first-child{flex:1}
.math-topic-group summary:hover{background:#f3f7fa}
.math-topic-group summary>.math-topic-count{padding:3px 7px;border-radius:5px;background:#f1f4f7;font-size:11px;color:var(--ui-muted)}
.math-topic-children a{min-height:42px;display:flex;align-items:center;justify-content:space-between;gap:10px;font:400 13px/1.5 var(--ui-font)}
.math-topic-children a .math-topic-count{float:none;margin-left:auto}
.math-topic-picker{padding:0;border-color:var(--ui-line);border-radius:10px;font-family:var(--ui-font)}
.math-topic-picker>.math-topics{padding:18px}
.math-topic-picker>summary{padding:15px 18px;font:600 14px/1.5 var(--ui-font)}
.math-topic-picker .math-topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
.page-heading{padding:10px 0 20px;color:var(--ui-ink);white-space:normal}
.page-heading h1{margin:0 0 10px;font:730 28px/1.3 var(--ui-font);letter-spacing:-.6px;white-space:normal!important;overflow-wrap:anywhere}
.page-heading>p{margin:0;color:var(--ui-muted);font-size:13px;line-height:1.6}
.page-heading-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.page-heading-actions>a{display:inline-flex;align-items:center;min-height:42px;margin:0;padding:10px 14px;border-radius:8px;font:600 13px/1.4 var(--ui-font);text-decoration:none}
.catalog-summary{border:0;border-left:3px solid #d2dce6;border-radius:0;background:transparent;box-shadow:none;padding:8px 16px;color:var(--ui-muted);font:400 13px/1.65 var(--ui-font)}
.study-guide-section{margin:54px 0;padding:36px 32px 38px;background:var(--ui-ink);border-radius:18px;color:#fff;white-space:normal}
.study-guide-section>.study-eyebrow{color:#bfccd8;margin-bottom:13px}
.study-guide-section h2{margin:0;font:700 32px/1.25 var(--ui-font);color:#fff;letter-spacing:-.7px}
.study-steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:30px;padding:0;margin:30px 0;list-style:none}
.study-steps li>span{display:grid;place-items:center;width:31px;height:31px;margin-bottom:14px;background:#ffffff12;border:1px solid #ffffff40;border-radius:50%;color:var(--ui-yellow);font-size:13px}
.study-steps h3{margin:0 0 8px;font:650 16px/1.5 var(--ui-font);color:#fff}
.study-steps p{margin:0;color:#d0dae4;font:400 13px/1.75 var(--ui-font)}
.study-faq{display:grid;grid-template-columns:1fr 1.6fr;gap:35px;margin:45px 0 50px;white-space:normal}
.study-faq .study-eyebrow{margin-bottom:10px}
.study-faq h2{margin:0;font:740 29px/1.25 var(--ui-font);letter-spacing:-.6px;color:var(--ui-ink)}
.study-faq-items>details{border-bottom:1px solid var(--ui-line)}
.study-faq-items>details:first-child{border-top:1px solid var(--ui-line)}
.study-faq-items summary{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:19px 0;cursor:pointer;list-style:none;font-size:14px;font-weight:650;color:var(--ui-ink)}
.study-faq-items summary::-webkit-details-marker{display:none}
.study-faq-items summary .ui-icon{width:18px;height:18px}
.study-faq-items details[open] summary .ui-icon{transform:rotate(180deg)}
.study-faq-items p{margin:0 0 20px;font-size:13px;line-height:1.75;color:var(--ui-muted)}
.telegram-banner{display:flex;align-items:center;justify-content:space-between;gap:24px;margin:28px 0;padding:26px 28px;border:1px solid #d1e1ee;border-radius:14px;background:#eaf2f8;color:var(--ui-ink);box-shadow:none;font-family:var(--ui-font);white-space:normal}
.telegram-banner-copy{display:grid;gap:6px}
.telegram-banner-copy strong{font:700 19px/1.4 var(--ui-font)}
.telegram-banner-copy span{max-width:550px;font:400 13px/1.65 var(--ui-font);color:var(--ui-muted)}
.telegram-banner a.telegram-banner-action{display:inline-flex;align-items:center;justify-content:center;gap:12px;flex:none;min-height:48px;padding:12px 18px;border-radius:9px;background:#2076aa;color:#fff;font:650 13px/1.5 var(--ui-font);text-decoration:none}
.telegram-banner-action span{font-weight:400}
.site-footer{margin:46px 0 0;padding:30px 0 20px;border-top:1px solid var(--ui-line);white-space:normal;color:var(--ui-muted)}
.site-footer-top{display:flex;align-items:flex-start;gap:35px}
.site-footer-top>p{margin:2px 0;font:400 12px/1.7 var(--ui-font)}
.site-footer-top>nav{display:grid;grid-template-columns:repeat(2,max-content);gap:10px 30px;margin-left:auto;font:500 12px/1.6 var(--ui-font)}
.site-footer a{color:var(--ui-ink)}
.site-footer a:hover{text-decoration:underline}
.site-footer-bottom{display:flex;justify-content:space-between;gap:20px;margin-top:27px;padding-top:18px;border-top:1px solid var(--ui-line);font:400 10px/1.6 var(--ui-font)}
.exam-page>main,.math-hub-page,.page{max-width:1200px;padding:24px;margin:auto}
.exam-page>.site-header,.account-page>.site-header{max-width:1200px;margin:auto}
.exam-page>main>.exam-intro{padding:30px 0 35px;margin:0}
.exam-intro h1{max-width:880px;font:750 44px/1.14 var(--ui-font);letter-spacing:-1.7px;color:var(--ui-ink)}
.exam-intro>p{max-width:760px;margin-top:20px;color:var(--ui-muted);font:400 16px/1.75 var(--ui-font)}
.exam-intro .subject-stats{display:inline-block;padding:9px 14px;border-radius:7px;background:#e9f0e9;color:var(--ui-green);font-size:13px;font-weight:650}
.subject-jumps{gap:8px}
.subject-jumps a{border-color:var(--ui-line);color:var(--ui-ink);background:#fff;font:600 13px/1.5 var(--ui-font)}
.subject-jumps a:first-child{border-color:var(--ui-yellow);background:var(--ui-yellow);color:var(--ui-ink)}
.subject-section{padding:26px;border:1px solid var(--ui-line);border-radius:14px;scroll-margin-top:106px}
.subject-section h2{font:740 27px/1.25 var(--ui-font);letter-spacing:-.6px}
.subject-section>p{font:400 14px/1.7 var(--ui-font);color:var(--ui-muted)}
.topic-card{padding:20px;border:1px solid var(--ui-line);border-radius:10px;background:#fafbfc}
.topic-card h3{font:650 16px/1.5 var(--ui-font)}
.topic-card h3 a{color:var(--ui-ink);text-decoration:none}
.topic-card h3 a:hover{text-decoration:underline}
.topic-card p{font:400 12px/1.5 var(--ui-font)}
.topic-card .topic-example{font:500 12px/1.6 var(--ui-font);text-underline-offset:3px}
.subject-card{border:1px solid var(--ui-line);border-radius:16px;box-shadow:none;padding:30px}
.subject-card h2{font:750 30px/1.2 var(--ui-font);letter-spacing:-.8px}
.subject-card>p{color:var(--ui-muted);font-size:14px}
.subject-card .subject-stats{font-weight:650;color:var(--ui-green)}
.subject-card .part-link{padding:14px;background:var(--ui-yellow);border-color:var(--ui-yellow);color:var(--ui-ink);font-size:14px}
.subject-card .subject-topics a{font-size:12px;padding:9px 10px;color:var(--ui-ink);background:#f8fafc}
.subject-card h3{font-size:15px}
.subject-overview-link{font-size:13px;color:#1d6096}
.subject-choice-heading{margin:4px 0 25px}
.subject-choice-heading h2{font:740 30px/1.25 var(--ui-font);letter-spacing:-.8px;margin:0 0 8px;color:var(--ui-ink)}
.subject-choice-heading p{color:var(--ui-muted);margin:0;font-size:14px}
.exam-search{background:#fff;border-color:var(--ui-line);border-radius:14px}
.exam-search label{font:650 16px/1.5 var(--ui-font)}
.exam-search input{font:400 16px var(--ui-font);border-color:#a6b4c1}
.exam-search button{font:650 14px var(--ui-font);min-height:46px}
.math-hub-page>.site-header,.page>.site-header{margin:-24px -24px 24px}
.math-hub-intro{padding:30px;border-radius:16px;border-color:var(--ui-line);box-shadow:none}
.math-hub-intro h1{font:740 38px/1.2 var(--ui-font);letter-spacing:-1px}
.math-hub-intro p{font:400 15px/1.8 var(--ui-font);color:var(--ui-muted)}
.math-hub-actions a{border-color:var(--ui-line);font:650 14px/1.5 var(--ui-font)}
.math-hub-actions .math-hub-all{background:var(--ui-yellow);border-color:var(--ui-yellow);color:var(--ui-ink)}
.math-hub-section{border:0;padding:20px 0;background:transparent;box-shadow:none}
.math-hub-grid{grid-template-columns:repeat(3,minmax(0,1fr))}
.math-hub-card{background:#fff;border-color:var(--ui-line);border-radius:12px}
.math-hub-card h3{font:650 17px/1.4 var(--ui-font);color:var(--ui-ink)}
.math-hub-card p{font:400 12px/1.7 var(--ui-font);color:var(--ui-muted)}
.math-hub-card small{font:650 12px var(--ui-font);color:var(--ui-green)}
.account-page main{padding-top:32px}
.account-page .card{border-color:var(--ui-line);border-radius:14px;box-shadow:none}
.account-page .card h1{font-family:var(--ui-font)}
.account-page button{min-height:44px}
.about-card{border-radius:14px;border-color:var(--ui-line);box-shadow:none}
.about-card p{font:400 15px/1.85 var(--ui-font);color:var(--ui-muted)}
.solution-button{min-height:44px;border-radius:8px}
.task-sequence-pager,.local-pager{border:1px solid var(--ui-line);box-shadow:none}
.task-sequence-pager a,.local-pager button{min-height:42px}
.task-sequence-pager-label{font-size:12px}
.local-pager[hidden]{display:none}
.exam-intro>.study-eyebrow{margin:0 0 16px;font:650 11px/1.5 var(--ui-font)}
.seo-task-solution{border-radius:12px;scroll-margin-top:110px}
.seo-task-solution h2,#comments,#feedback{scroll-margin-top:110px}
.comments-widget{z-index:65}
/* Task discussions already have an inline section and links; keep their controls unobstructed. */
body:has(.seo-task-solution) .comments-widget,body:has(.about-card) .comments-widget{display:none}
@media(min-width:1600px){.study-hero h1{font-size:64px}}
@media(max-width:1100px){.site-header.local-header{gap:15px}.site-desktop-nav{gap:14px}.site-header-actions{gap:13px}.site-account{display:none}.study-hero{gap:28px}.study-hero h1{font-size:48px}.study-lead{font-size:16px}.study-stats{gap:16px}.study-stats>div+div{padding-left:16px}.study-actions{gap:12px}.study-preview{padding-left:0;padding-right:0}.study-preview-card{padding-left:20px;padding-right:20px}}
@media(max-width:900px){
  .site-desktop-nav,.site-header-actions>.site-header-cta{display:none}.site-mobile-menu{display:block}
  .site-header.local-header{min-height:74px;padding:12px 20px}.site-header-actions{gap:12px}
  .site-mobile-menu>summary{display:flex;align-items:center;gap:7px;min-height:44px;padding:8px 10px;list-style:none;cursor:pointer;border:1px solid var(--ui-line);border-radius:8px;font-size:12px;font-weight:650}
  .site-mobile-panel{position:absolute;top:100%;left:0;right:0;max-height:calc(100dvh - 74px);overflow:auto;overscroll-behavior:contain;padding:14px 20px 22px;background:#fff;border-top:1px solid var(--ui-line);border-bottom:1px solid var(--ui-line);box-shadow:0 20px 35px #192f491c}
  .site-mobile-panel>a{display:flex;align-items:center;justify-content:space-between;min-height:46px;padding:12px;color:var(--ui-ink);border-radius:8px;font-size:14px}
  .site-mobile-panel>a.site-mobile-start{margin-bottom:12px;background:var(--ui-yellow);font-weight:700}
  .site-mobile-panel>details>summary{display:flex;align-items:center;gap:10px;padding:14px 12px;min-height:48px;list-style:none;cursor:pointer;font-weight:650}
  .site-mobile-panel>details>summary>.ui-icon:last-child{margin-left:auto;width:17px;height:17px}
  .site-mobile-panel>details>div{display:grid;margin:0 8px 10px 20px;padding-left:12px;border-left:1px solid var(--ui-line)}
  .site-mobile-panel>details>div>a{display:block;padding:11px;color:var(--ui-muted);font-size:13px;min-height:44px}
  .site-mobile-panel a:hover,.site-mobile-panel a[aria-current]{background:#edf3f7;color:#1d6096}
  .site-search-panel{right:-90px}.study-hero{gap:22px}.study-hero h1{font-size:42px;letter-spacing:-1.8px}.study-lead{font-size:15px;line-height:1.75}
  .study-preview-question{font-size:15px}.study-preview-sketch{font-size:16px}.study-stats{gap:12px}.study-stats>div+div{padding-left:12px}.study-stats strong{font-size:22px}
  .study-stats span{font-size:10px}.study-preview-top strong{font-size:12px}.study-preview-top div>span{font-size:9px}.study-example-tag{display:none}
  .study-hero-copy .study-actions{gap:8px}.study-hero-copy .study-secondary{font-size:12px}.study-hero-copy .study-button{font-size:14px;padding:13px 17px}
  .math-topic-grid,.math-hub-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.study-benefits{gap:15px}.study-benefits>div{gap:9px}.study-benefits h2{font-size:12px}.study-benefits p{font-size:11px}
  .site-footer-top{gap:24px;flex-wrap:wrap}.site-footer-top>nav{gap:9px 20px}.site-footer-top>p{display:none}
}
@media(max-width:700px){
  html{scroll-padding-top:0}body.questions-container{padding:16px;overflow-x:clip}
  .site-header.local-header{min-height:70px;padding:11px 16px;gap:12px}.site-brand{font-size:18px;gap:9px}.site-brand-mark{width:35px;height:39px;border-radius:10px}.site-brand-mark .ui-icon{width:23px;height:23px}.site-brand small,.site-header .site-brand small{font-size:10px;margin-top:4px}
  body.questions-container>.site-header{margin:-16px -16px 17px}.site-search>summary{width:29px}.site-header-actions{gap:7px}.site-mobile-menu>summary{padding:7px 9px}.site-mobile-menu>summary .ui-icon{width:19px}
  .site-search-panel{position:fixed;top:76px;left:12px;right:12px;width:auto;max-height:calc(100dvh - 90px)}.site-mobile-panel{max-height:calc(100dvh - 70px);padding:12px 16px 20px}
  .seo-breadcrumbs{font-size:10px;margin-bottom:17px;line-height:1.7}.study-hero{grid-template-columns:1fr;gap:26px;padding:13px 2px 32px}.study-hero h1{font-size:clamp(30px,9.6vw,40px);line-height:1.1;letter-spacing:-1.9px;margin-bottom:19px}.study-hero h1 em:after{height:9px;bottom:2px}
  .study-eyebrow{font-size:10px;letter-spacing:1px;margin-bottom:18px}.study-lead{font-size:15px;line-height:1.75;margin-bottom:20px;max-width:none}
  .study-hero-copy .study-actions{display:grid;grid-template-columns:1fr;gap:7px}.study-hero-copy .study-button{font-size:15px;min-height:52px;padding:13px 20px}.study-hero-copy .study-secondary{justify-content:center;font-size:13px;min-height:40px}
  .study-reassurance{justify-content:center;margin:9px 0 23px;font-size:10px;gap:5px}.study-reassurance .ui-icon{width:13px;height:13px}
  .study-stats{justify-content:space-between;padding-top:20px;gap:14px}.study-stats>div{flex:1}.study-stats>div+div{padding-left:16px}.study-stats strong{font-size:24px}.study-stats span{font-size:10px;max-width:110px}
  .study-preview{padding:5px 0 0;margin:0 5px}.study-preview-card{padding:26px 21px 16px;border-radius:14px}.study-preview:before{inset:40px -4px 45px 15px;transform:rotate(3deg);border-radius:15px}.study-preview-top strong{font-size:14px}.study-preview-top div>span{font-size:10px}.study-preview-question{font-size:16px;line-height:1.6;margin:17px 0}.study-preview-sketch{font-size:17px;padding:14px 8px;gap:5px}.study-preview-note{font-size:10px;padding:9px 12px}.study-preview-caption{font-size:10px;margin-top:18px}
  .study-benefits{grid-template-columns:1fr;gap:17px;padding:23px 0;margin-bottom:30px}.study-benefits>div{gap:13px}.study-benefits h2{font-size:14px;margin-bottom:3px}.study-benefits p{font-size:12px}.study-benefits>div>span{width:32px;height:32px}
  #practice,#subjects,#part-1,#part-2,#study-guide,#how-to-study{scroll-margin-top:88px}
  .study-subject-switch{width:100%;margin-bottom:23px}.study-subject-switch>a{flex:1;padding:10px 7px;gap:6px;font-size:12px;min-height:44px}.study-subject-switch span{font-size:9px}.study-subject-switch .ui-icon{width:18px}
  .math-topics{padding:0}.math-topics-heading{gap:15px;margin-bottom:16px}.math-topics-heading h2{font-size:25px;letter-spacing:-.6px}.math-topics-heading p{font-size:12px;margin-top:6px}.math-all-link{min-height:44px;font-size:12px}
  .math-topic-grid,.math-topic-picker .math-topic-grid{grid-template-columns:1fr;gap:9px}.math-topic-group summary{min-height:62px;padding:13px 15px;font-size:14px}.math-topic-picker>.math-topics{padding:14px}
  .page-heading{padding:5px 0 18px}.page-heading h1{font-size:23px;line-height:1.3;letter-spacing:-.5px}.page-heading>p{font-size:12px}.page-heading-actions{gap:7px}.page-heading-actions>a{font-size:12px;min-height:42px;padding:10px 12px}
  .study-guide-section{margin:32px 0;padding:26px 23px 30px;border-radius:14px}.study-guide-section h2{font-size:27px;letter-spacing:-.5px}.study-steps{grid-template-columns:1fr;gap:22px;margin:25px 0}.study-steps li{position:relative;padding-left:45px}.study-steps li>span{position:absolute;left:0;top:0;width:29px;height:29px;margin:0}.study-steps h3{font-size:16px}.study-steps p{font-size:13px}.study-guide-section>.study-button{width:100%;min-height:50px;font-size:13px;gap:12px;padding:13px 12px}
  .study-faq{grid-template-columns:1fr;gap:22px;margin:30px 0}.study-faq h2{font-size:27px}.study-faq-items summary{font-size:13px;line-height:1.6;padding:16px 0}.study-faq-items p{font-size:12px}
  .telegram-banner{flex-direction:column;align-items:stretch;gap:18px;padding:24px 21px;margin:28px 0;border-radius:12px}.telegram-banner-copy strong{font-size:20px;line-height:1.35}.telegram-banner-copy span{font-size:13px}.telegram-banner a.telegram-banner-action{width:100%;min-height:48px;font-size:13px;gap:7px}
  .site-footer{margin-top:32px;padding:25px 0 18px}.site-footer-top{display:grid;grid-template-columns:1fr;gap:24px}.site-footer-top>nav{margin:0;grid-template-columns:1fr 1fr;gap:8px 14px;font-size:12px}.site-footer-top>nav>a{padding:8px 0;min-height:36px}.site-footer-bottom{flex-direction:column;gap:10px;margin-top:20px;padding-top:15px;font-size:10px}
  .exam-page>main,.math-hub-page,.page{padding:16px}.math-hub-page>.site-header,.page>.site-header{margin:-16px -16px 17px}.exam-page>main>.exam-intro{padding:15px 0 24px}.exam-intro h1{font-size:32px;line-height:1.2;letter-spacing:-1px}.exam-intro>p{font-size:14px;line-height:1.75;margin-top:16px}.exam-intro .subject-stats{font-size:12px;padding:8px 11px}
  .subject-jumps{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:19px}.subject-jumps>a{text-align:center;padding:12px 9px;font-size:12px}.subject-jumps>a:last-child{grid-column:1/-1}.subject-section{padding:20px 16px;border-radius:12px;scroll-margin-top:88px}.subject-section h2{font-size:23px}.subject-section>p{font-size:13px}.topic-card{padding:16px}.topic-card h3{font-size:15px}.topic-card .topic-example{min-height:38px;display:inline-flex;align-items:center}
  .subject-card{padding:24px 21px;border-radius:14px}.subject-card h2{font-size:27px}.subject-card p{font-size:13px}.subject-choice-heading h2{font-size:26px}.subject-choice-heading p{font-size:13px}.subject-choice-heading{margin-bottom:20px}.exam-search{padding:22px 19px}.exam-search label{font-size:15px}.exam-search-row{flex-wrap:nowrap}.exam-search input{flex-basis:auto;width:100%;padding:11px;font-size:16px}.exam-search button{padding:11px 13px;font-size:13px}
  .math-hub-intro{padding:23px 20px}.math-hub-intro h1{font-size:29px}.math-hub-intro p{font-size:14px}.math-hub-grid{grid-template-columns:1fr}.math-hub-section{padding:16px 0}.math-hub-actions{display:grid;grid-template-columns:1fr}.math-hub-actions>a{text-align:center;font-size:13px}
  .about-card{padding:22px 20px}.about-card p{font-size:14px}.about-card h1{font:740 29px/1.2 var(--ui-font)}
  .account-page main{padding:22px 16px 30px}.account-page input{font-size:16px}
  .comments-widget{right:12px;bottom:12px}.comments-widget-toggle{font-size:12px}
  .catalogue-task-start{scroll-margin-top:88px}.seo-task-solution,.seo-task-solution h2{scroll-margin-top:88px}
}
@media(max-width:359px){.site-brand{font-size:16px}.site-header-actions{gap:3px}.site-mobile-menu>summary{font-size:11px;gap:4px}.study-stats{gap:10px}.study-stats>div+div{padding-left:10px}.study-subject-switch span{display:none}.study-preview-top strong{font-size:12px}.study-preview-card{padding-left:16px;padding-right:16px}.study-reassurance{font-size:9px}.study-preview-sketch{font-size:15px}}
@media(max-width:359px){.study-exam-links>div{grid-template-columns:3em repeat(2,max-content)}.study-exam-links>div>a:last-child{grid-column:2 / -1}}
@media(max-width:359px){.site-header.local-header{padding-left:10px;padding-right:10px;gap:8px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important}}
.prep-banner{box-sizing:border-box;display:grid;grid-template-columns:260px minmax(0,1fr) auto;align-items:center;gap:24px;margin:24px 0;padding:24px;border:1px solid #d2decf;border-radius:18px;background:#f0f5ec;color:#192f49;font-family:var(--ui-font)}
.prep-banner *{box-sizing:border-box}
.prep-banner-art{align-self:stretch;min-width:0}
.prep-banner-art img{display:block;width:100%;height:100%;min-height:190px;object-fit:cover;object-position:50% 40%;border-radius:12px}
.prep-banner h2 span{white-space:nowrap}
.prep-banner .prep-banner-eyebrow{margin:0 0 8px;color:#416544;font-size:12px;font-weight:600;line-height:1.4}
.prep-banner h2{margin:0 0 12px;color:#192f49;font:800 clamp(22px,2.5vw,28px)/1.15 var(--ui-font);letter-spacing:-.6px}
.prep-banner-subjects{display:flex;flex-wrap:wrap;gap:6px;margin:0 0 12px;padding:0;list-style:none}
.prep-banner-subjects li{margin:0;padding:4px 9px;border:1px solid #d2decf;border-radius:6px;background:#fffdf7;font:600 12px/1.4 var(--ui-font)}
.prep-banner .prep-banner-description{max-width:540px;margin:0;color:#4d6154;font:400 14px/1.55 var(--ui-font)}
.prep-banner-actions{display:grid;gap:12px;justify-items:center}
.prep-banner a.prep-banner-primary{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:48px;padding:13px 18px;border-radius:9px;background:#276951;color:#fff;text-decoration:none;font:700 14px/1.4 var(--ui-font)}
.prep-banner a.prep-banner-primary:hover{background:#1e523f;color:#fff}
.prep-banner a.prep-banner-secondary{display:inline-flex;align-items:center;justify-content:center;min-height:36px;color:#276951;text-decoration:underline;text-underline-offset:4px;font:500 12px/1.4 var(--ui-font)}
.prep-banner a:focus-visible{outline:3px solid #357ac5;outline-offset:4px}
@media(max-width:1000px){.prep-banner{grid-template-columns:220px minmax(0,1fr);gap:20px}.prep-banner-art{grid-row:span 2;align-self:center}.prep-banner-art img{height:auto;min-height:0;aspect-ratio:3/2}.prep-banner-actions{grid-column:2;justify-items:start;gap:7px}}
@media(max-width:620px){.prep-banner{grid-template-columns:minmax(0,1fr);gap:20px;margin:20px 0;padding:18px}.prep-banner-art{grid-row:auto}.prep-banner-art img{height:auto;min-height:0;aspect-ratio:3/2}.prep-banner-actions{grid-column:auto;justify-items:stretch;gap:7px}.prep-banner h2{font-size:25px}.prep-banner .prep-banner-eyebrow{font-size:11px}}
@media print{.prep-banner{display:none!important}}
.site-ad{display:none;width:100%;max-width:760px;min-height:70px;margin:28px auto;font-family:var(--ui-font)}
.site-js .site-ad{display:block}
.site-ad[hidden]{display:none!important}
.site-ad[data-ad-state="empty"]{visibility:hidden;pointer-events:none}
.site-ad-slot{min-height:50px;width:100%}
.site-ad-label{display:block;font-size:10px;line-height:14px;color:var(--ui-muted);text-align:center;margin-bottom:6px}
.site-ad-label[hidden]{display:block!important;visibility:hidden}
@media print{.site-header,.site-footer,.site-ad,.study-actions,.study-guide-section,.comments-widget{display:none!important}}

/* Catalogue search and the crawlable fallback for server pagination. */
.catalogue-search{max-width:1100px;margin:18px auto;padding:14px 16px;background:#fff;border:1px solid var(--ui-line);border-radius:9px;font-family:var(--ui-font)}
.catalogue-search label{display:block;margin-bottom:8px;font-size:14px;font-weight:650}
.catalogue-search>div{display:flex;gap:8px}
.catalogue-search input[type=search]{flex:1;min-width:0;min-height:44px;padding:10px;border:1px solid #aebdcb;border-radius:6px;font:16px var(--ui-font)}
.catalogue-search button{min-height:44px;padding:10px 15px;border:0;border-radius:6px;background:#183153;color:white;font:600 14px var(--ui-font);cursor:pointer}
.catalogue-search p{margin:8px 0 0;font-size:14px}
.catalogue-guide details{margin:10px 0;font-family:var(--ui-font);font-size:14px}
.catalogue-guide summary{cursor:pointer;font-weight:650}
.catalogue-guide nav{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:14px;font-family:var(--ui-font)}
.catalogue-guide nav a{padding:5px 0}
.local-pager a{display:inline-flex;align-items:center;justify-content:center;min-width:38px;min-height:40px;padding:8px 11px;border:1px solid #b8c3d1;border-radius:6px;background:white;color:#183153;text-decoration:none;font:14px Arial,sans-serif}
.local-pager a.active{background:#183153;color:white}
.solution-task-link{display:inline-block}
.catalogue-next-task{min-height:44px!important}
.catalogue-complete{padding:16px;background:#e9f5ec;border-radius:8px}
@media(max-width:600px){.catalogue-search{padding:12px}.catalogue-guide nav{gap:5px 14px}.catalogue-guide nav a{min-height:36px}.local-pager button,.local-pager a{min-height:44px}}

/* Completed visitor requests, linked to the updated solutions. */
.visitor-updates{margin:24px 0;padding:24px;border:1px solid #b8d4c5;border-left:5px solid #276951;border-radius:14px;background:#edf6f0;color:#192f49;font:400 14px/1.6 var(--ui-font)}
.visitor-updates *{box-sizing:border-box}
.visitor-updates-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;margin-bottom:18px}
.visitor-updates .visitor-updates-eyebrow{margin:0 0 5px;color:#276951;font-size:12px;font-weight:750}
.visitor-updates-eyebrow span{margin-right:5px}
.visitor-updates h2{margin:0;color:#192f49;font:750 24px/1.25 var(--ui-font);letter-spacing:-.4px}
.visitor-updates time{flex-shrink:0;padding-top:3px;color:#4c6659;font-size:12px}
.visitor-updates-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:0;padding:0;list-style:none}
.visitor-updates-list>li{display:flex;flex-direction:column;min-width:0;margin:0;padding:18px;border:1px solid #d2e3d8;border-radius:10px;background:#fff}
.visitor-update-top{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px;margin-bottom:10px}
.visitor-updates a.visitor-update-task{color:#174f3c;font-weight:750;text-decoration:underline;text-underline-offset:3px}
.visitor-update-status{padding:3px 9px;border-radius:20px;background:#e1f1e7;color:#20583f;font-size:11px;font-weight:700}
.visitor-updates h3{margin:0 0 6px;color:#192f49;font:700 16px/1.4 var(--ui-font)}
.visitor-updates-list p{margin:0 0 12px;color:#455a50;font:400 14px/1.6 var(--ui-font)}
.visitor-updates a.visitor-update-link{align-self:flex-start;display:inline-flex;align-items:center;min-height:44px;margin-top:auto;color:#174f3c;font-weight:700;text-decoration:underline;text-underline-offset:4px}
.visitor-updates a:hover{color:#0e392a}
.visitor-updates a:focus-visible{outline:3px solid #357ac5;outline-offset:4px;border-radius:3px}
.visitor-updates-task .visitor-updates-list{grid-template-columns:minmax(0,1fr)}
.visitor-updates-task h2{font-size:21px}
@media(max-width:700px){.visitor-updates{padding:18px 15px;margin:20px 0}.visitor-updates-heading{flex-direction:column;gap:8px;margin-bottom:14px}.visitor-updates h2{font-size:21px}.visitor-updates-list{grid-template-columns:minmax(0,1fr)}.visitor-updates-list>li{padding:15px}.visitor-update-top{gap:7px}.visitor-updates time{padding:0}}
@media print{.visitor-updates{display:none!important}}

/* Contact form in the former Telegram banner position. */
.study-request{scroll-margin-top:90px;display:grid;grid-template-columns:.85fr 1.15fr;gap:36px;margin:30px 0;padding:32px;border:1px solid #d1e1ee;border-radius:16px;background:#edf4f9;color:var(--ui-ink);font:400 15px/1.65 var(--ui-font);white-space:normal}
.study-request *{box-sizing:border-box}.study-request-copy,.study-request-body{min-width:0}
.study-request .study-request-eyebrow{margin:0 0 10px;color:#28658c;font-size:11px;font-weight:700;letter-spacing:1px;text-transform:uppercase}
.study-request h2{margin:0 0 14px;font:700 30px/1.2 var(--ui-font);letter-spacing:-.6px;color:var(--ui-ink)}
.study-request-copy>p:last-child{max-width:360px;margin:0;color:var(--ui-muted);font:400 15px/1.75 var(--ui-font)}
.study-request-form{display:grid;gap:14px;margin:0}.study-request-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.study-request-form label{display:grid;gap:6px;margin:0;font:600 13px/1.5 var(--ui-font);color:var(--ui-ink)}
.study-request-form input:not([type=checkbox]),.study-request-form select,.study-request-form textarea{width:100%;min-width:0;min-height:46px;margin:0;padding:11px 12px;border:1px solid #b8cbda;border-radius:8px;background:#fff;color:var(--ui-ink);font:400 16px/1.4 var(--ui-font);box-shadow:none}
.study-request-form textarea{min-height:94px;resize:vertical}.study-request-form input:focus-visible,.study-request-form select:focus-visible,.study-request-form textarea:focus-visible,.study-request button:focus-visible{outline:3px solid #79b0d3;outline-offset:2px}
.study-request-form .study-request-consent{display:flex;align-items:flex-start;gap:9px;font-size:12px;font-weight:400;line-height:1.65}.study-request-consent input{width:18px;height:18px;flex:0 0 18px;margin:2px 0 0;accent-color:#2076aa}
.study-request a{color:#1e648e;text-decoration:underline}.study-request .study-request-hint{margin:-7px 0 0;color:var(--ui-muted);font-size:12px}
.study-request button{min-height:48px;padding:12px 18px;border:0;border-radius:9px;background:#2076aa;color:#fff;font:650 14px/1.5 var(--ui-font);cursor:pointer}.study-request button:hover{background:#195c86}.study-request button:disabled{cursor:wait;opacity:.65}
.study-request-submit{display:flex;align-items:center;justify-content:space-between;width:100%}.study-request-error{margin:0;color:#962d25;font-size:14px}.study-request-success{padding:24px;border:1px solid #a9ccb7;border-radius:12px;background:#f4fbf6}.study-request-success h3{margin:0;color:#225f3e}.study-request-success p{margin:10px 0 20px}
.study-request [hidden]{display:none!important}.study-request-form .study-request-trap{position:absolute;left:-10000px;width:1px;height:1px;overflow:hidden}
@media(max-width:900px){.study-request{grid-template-columns:1fr;gap:22px}.study-request-copy>p:last-child{max-width:none}}
@media(max-width:600px){.study-request{margin:24px 0;padding:22px 16px;border-radius:12px}.study-request h2{font-size:26px}.study-request-grid{grid-template-columns:1fr}}