@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;800&family=Source+Serif+4:ital,wght@1,600&display=swap');

:root{--navy:#102a43;--navy-2:#173f5f;--ink:#14202b;--muted:#60758a;--teal:#21a694;--teal-light:#dff5f1;--cream:#f6f4ed;--paper:#fff;--line:#dce5ea;--orange:#ffb15c;--red:#c95353;--green:#27866f;--shadow:0 24px 70px rgba(16,42,67,.11);--radius:24px;--container:1180px}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;color:var(--ink);background:#fbfcfc;font-family:Manrope,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.65;-webkit-font-smoothing:antialiased}
img,svg,canvas{display:block;max-width:100%}
a{color:inherit}
button,input{font:inherit}
button{color:inherit}
.container{width:min(calc(100% - 40px),var(--container));margin-inline:auto}
.narrow-container{max-width:920px}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip-link{position:fixed;z-index:9999;left:20px;top:10px;transform:translateY(-150%);background:var(--navy);color:#fff;padding:10px 16px;border-radius:10px;text-decoration:none}.skip-link:focus{transform:none}
.site-header{height:82px;display:flex;align-items:center;background:rgba(255,255,255,.92);border-bottom:1px solid rgba(220,229,234,.85);position:sticky;top:0;z-index:100;backdrop-filter:blur(16px)}
.site-header.scrolled{box-shadow:0 10px 35px rgba(16,42,67,.08)}
.nav-wrap{display:flex;align-items:center;justify-content:space-between;height:100%}
.brand{display:inline-flex;align-items:center;gap:11px;text-decoration:none}.brand-mark{display:grid;place-items:center;width:42px;height:42px;border-radius:12px;background:var(--navy);color:#66ddcd;font-weight:800;font-size:25px}.brand>span:last-child{display:flex;flex-direction:column;line-height:1.2}.brand strong{font-size:16px;letter-spacing:.02em}.brand small{font-size:10px;color:var(--muted);margin-top:3px}
.site-nav{display:flex;align-items:center;gap:8px}.site-nav a{text-decoration:none;color:#42576b;font-size:14px;font-weight:700;padding:11px 14px;border-radius:10px}.site-nav a:hover,.site-nav a.active{color:var(--navy);background:#edf6f5}
.menu-button{display:none;width:44px;height:42px;background:transparent;border:0;padding:9px;cursor:pointer}.menu-button span:not(.sr-only){display:block;width:24px;height:2px;background:var(--navy);margin:5px 0;border-radius:3px;transition:.2s}
.hero{position:relative;min-height:700px;background:linear-gradient(120deg,#f8faf9 0%,#eef7f5 100%);overflow:hidden;display:flex;align-items:center;padding:74px 0 82px}.hero-grid{display:grid;grid-template-columns:1.08fr .92fr;gap:70px;align-items:center;position:relative;z-index:2}.hero-grid-lines{position:absolute;inset:0;background-image:linear-gradient(rgba(16,42,67,.035) 1px,transparent 1px),linear-gradient(90deg,rgba(16,42,67,.035) 1px,transparent 1px);background-size:64px 64px;mask-image:linear-gradient(to right,transparent,black 30%,black 70%,transparent);pointer-events:none}
.eyebrow{font-size:11px;text-transform:uppercase;letter-spacing:.19em;color:var(--teal);font-weight:800;margin:0 0 16px}.eyebrow.light{color:#9fe7dd}
h1,h2,h3,p{margin-top:0}h1,h2,h3{line-height:1.15;color:var(--navy)}h1{font-size:clamp(42px,5.35vw,72px);letter-spacing:-.055em;margin-bottom:26px}h1 em{font-family:"Source Serif 4",Georgia,serif;color:var(--teal);font-weight:600}.lead{font-size:18px;line-height:1.72;color:#4b6378;max-width:650px;margin-bottom:32px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap}.button{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:50px;padding:0 22px;border:1px solid transparent;border-radius:13px;text-decoration:none;font-weight:800;font-size:14px;cursor:pointer;transition:transform .2s,box-shadow .2s,background .2s}.button:hover{transform:translateY(-2px)}.button.primary{background:var(--navy);color:#fff;box-shadow:0 12px 25px rgba(16,42,67,.18)}.button.primary:hover{background:#173d5d}.button.ghost{border-color:#c8d6de;background:rgba(255,255,255,.75);color:var(--navy)}.button.ghost:hover{background:#fff;box-shadow:0 9px 25px rgba(16,42,67,.08)}
.hero-facts{display:flex;padding:0;margin:46px 0 0;list-style:none}.hero-facts li{display:flex;flex-direction:column;min-width:112px;padding:0 24px;border-left:1px solid #cfdde2}.hero-facts li:first-child{padding-left:0;border:0}.hero-facts strong{font-size:28px;color:var(--navy);line-height:1}.hero-facts span{font-size:11px;color:var(--muted);margin-top:7px;text-transform:uppercase;letter-spacing:.08em}
.hero-visual{display:flex;justify-content:center}.portrait-card{position:relative;width:min(100%,470px);aspect-ratio:4/5;padding:17px;border-radius:180px 180px 30px 30px;background:linear-gradient(145deg,#bfe8e1,#f2d6b5);box-shadow:var(--shadow)}.portrait-card:after{content:"";position:absolute;inset:17px;border:1px solid rgba(255,255,255,.7);border-radius:165px 165px 22px 22px;pointer-events:none}.portrait-card img{width:100%;height:100%;object-fit:cover;object-position:center;border-radius:164px 164px 20px 20px;filter:saturate(.92)}.portrait-caption{position:absolute;z-index:3;left:50%;bottom:30px;transform:translateX(-50%);width:max-content;max-width:90%;background:rgba(16,42,67,.92);color:#fff;padding:11px 16px;border-radius:999px;font-size:11px;font-weight:700;box-shadow:0 10px 25px rgba(16,42,67,.25)}.status-dot{display:inline-block;width:7px;height:7px;background:#5de0ba;border-radius:50%;margin-right:7px}.math-orbit{position:absolute;z-index:4;width:62px;height:62px;border-radius:19px;background:#fff;display:grid;place-items:center;font-family:Georgia,serif;font-style:italic;font-weight:700;color:var(--navy);font-size:22px;box-shadow:0 14px 35px rgba(16,42,67,.15)}.orbit-one{left:-28px;top:27%}.orbit-two{right:-20px;top:12%;background:var(--orange)}
.section{padding:104px 0}.section-heading{display:flex;align-items:flex-end;justify-content:space-between;gap:40px;margin-bottom:44px}.section-heading h2,.about-intro h2,.test-info-grid h2{font-size:clamp(32px,4vw,48px);letter-spacing:-.04em;margin:0}.section-heading>p{max-width:480px;color:var(--muted);margin:0}.section-heading.compact{max-width:720px}.grade-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.grade-card{min-height:360px;padding:34px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);text-decoration:none;display:flex;flex-direction:column;position:relative;overflow:hidden;transition:.25s}.grade-card:after{content:"";position:absolute;width:170px;height:170px;border:1px solid #dce7e9;border-radius:50%;right:-70px;top:-70px}.grade-card:hover{transform:translateY(-7px);box-shadow:var(--shadow);border-color:transparent}.grade-card.featured{background:var(--navy);color:#fff;border-color:var(--navy)}.grade-card.featured .grade-number,.grade-card.featured .grade-label,.grade-card.featured p{color:#fff}.grade-card.featured:after{border-color:rgba(255,255,255,.14)}.grade-number{font-size:92px;line-height:.9;font-weight:800;color:var(--navy);letter-spacing:-.08em}.grade-label{font-weight:800;color:var(--teal);text-transform:uppercase;letter-spacing:.12em;font-size:11px}.grade-card p{color:var(--muted);font-size:14px;margin:30px 0 24px;max-width:270px}.card-link{margin-top:auto;font-size:13px;font-weight:800;color:var(--teal)}
.about-section{background:var(--cream)}.about-grid{display:grid;grid-template-columns:1.08fr .92fr;gap:84px;align-items:start}.about-intro>p:not(.eyebrow){font-size:17px;color:#4b6174}.principles{margin-top:42px;border-top:1px solid #d9d8d1}.principles>div{display:grid;grid-template-columns:48px 1fr;gap:15px;padding:22px 0;border-bottom:1px solid #d9d8d1}.principles span{color:var(--teal);font-size:12px;font-weight:800}.principles p{margin:0;color:var(--muted);font-size:14px}.principles strong{display:block;color:var(--navy);font-size:16px;margin-bottom:3px}.timeline-card{background:#fff;border-radius:var(--radius);padding:36px;box-shadow:0 20px 60px rgba(16,42,67,.08)}.timeline-card h3{font-size:22px;margin-bottom:28px}.timeline{list-style:none;margin:0;padding:0}.timeline li{position:relative;padding:0 0 28px 28px;border-left:1px solid #d7e3e5}.timeline li:last-child{padding-bottom:4px}.timeline li:before{content:"";position:absolute;left:-5px;top:4px;width:9px;height:9px;border-radius:50%;background:#b8c9d0}.timeline li.current:before{background:var(--teal);box-shadow:0 0 0 6px var(--teal-light)}.timeline span{font-size:10px;text-transform:uppercase;letter-spacing:.12em;color:var(--teal);font-weight:800}.timeline strong{display:block;font-size:14px;color:var(--navy);margin-top:5px}.timeline p{font-size:12px;color:var(--muted);margin:3px 0 0}.education-note{display:flex;gap:13px;margin-top:24px;padding:18px;background:#edf6f5;border-radius:14px}.education-note>span{font-size:25px;color:var(--teal)}.education-note p{margin:0;font-size:12px;color:var(--muted)}.education-note strong{display:block;color:var(--navy);font-size:13px}
.learning-flow{background:#fff}.flow-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.flow-card{padding:27px 24px;border:1px solid var(--line);border-radius:18px}.flow-card>span{display:grid;place-items:center;width:34px;height:34px;background:var(--teal-light);color:var(--teal);border-radius:10px;font-size:12px;font-weight:800;margin-bottom:24px}.flow-card h3{font-size:17px}.flow-card p{font-size:13px;color:var(--muted);margin:0}.cta-section{padding-top:40px}.cta-card{background:var(--navy);color:#fff;padding:58px 64px;border-radius:30px;display:flex;justify-content:space-between;align-items:center;gap:30px;position:relative;overflow:hidden}.cta-card:after{content:"π";position:absolute;right:27%;top:-80px;font:240px Georgia,serif;color:rgba(255,255,255,.035)}.cta-card h2{color:#fff;font-size:clamp(28px,3.5vw,44px);max-width:740px;margin:0;letter-spacing:-.035em}.light-button{background:#fff;color:var(--navy);position:relative;z-index:2;white-space:nowrap}
.site-footer{background:#0b2236;color:#b8c8d5;padding:65px 0 22px}.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr;gap:50px;padding-bottom:54px}.footer-brand .brand-mark{background:#183b57}.footer-brand strong{color:#fff}.footer-grid>div{display:flex;flex-direction:column;align-items:flex-start;gap:9px}.footer-grid p{font-size:12px;max-width:250px;margin:10px 0 0}.footer-grid>div>strong{color:#fff;font-size:13px;margin-bottom:5px}.footer-grid a,.footer-grid span{font-size:12px;text-decoration:none}.footer-grid a:hover{color:#fff}.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:20px;display:flex;justify-content:space-between;gap:20px;font-size:10px;letter-spacing:.04em}.footer-bottom a{text-decoration:none}
.page-hero{padding:86px 0 80px;background:var(--navy);color:#dce8ef;position:relative;overflow:hidden}.page-hero:after{content:"";position:absolute;right:-120px;top:-220px;width:500px;height:500px;border:1px solid rgba(255,255,255,.12);border-radius:50%;box-shadow:0 0 0 80px rgba(255,255,255,.018),0 0 0 160px rgba(255,255,255,.018)}.page-hero h1{color:#fff;font-size:clamp(45px,6vw,72px);margin-bottom:18px}.page-hero p:last-child{max-width:720px;color:#bdceda;margin:0;font-size:16px}.catalog-section{padding-top:58px}.catalog-controls{display:grid;grid-template-columns:auto auto 1fr;gap:28px;align-items:end;padding:19px 22px;border:1px solid var(--line);border-radius:18px;background:#fff;box-shadow:0 12px 40px rgba(16,42,67,.055)}.filter-group>span{display:block;font-size:10px;text-transform:uppercase;letter-spacing:.12em;color:var(--muted);font-weight:800;margin-bottom:8px}.segmented{display:flex;background:#eef3f4;border-radius:10px;padding:4px}.segmented button{border:0;background:transparent;min-width:46px;padding:8px 10px;border-radius:7px;cursor:pointer;font-size:12px;font-weight:800;color:#61778b}.segmented button.active{background:#fff;color:var(--navy);box-shadow:0 3px 10px rgba(16,42,67,.1)}.segmented.wide button{min-width:auto}.catalog-search{position:relative}.catalog-search input{width:100%;height:42px;border:1px solid var(--line);border-radius:10px;padding:0 42px 0 14px;outline:0;color:var(--navy)}.catalog-search input:focus{border-color:var(--teal);box-shadow:0 0 0 3px var(--teal-light)}.catalog-search>span{position:absolute;right:14px;top:8px;color:var(--muted)}.catalog-summary{display:flex;align-items:end;justify-content:space-between;margin:54px 0 25px}.catalog-summary h2{font-size:38px;margin:0}.catalog-summary>p{font-size:12px;color:var(--muted);margin:0}.subject-columns{display:grid;grid-template-columns:1fr 1fr;gap:26px}.subject-column{min-width:0}.subject-title{display:flex;align-items:center;gap:12px;margin-bottom:14px}.subject-icon{display:grid;place-items:center;width:36px;height:36px;border-radius:10px;background:var(--teal-light);color:var(--teal);font:italic 18px Georgia,serif}.subject-title h3{font-size:20px;margin:0}.topic-group{background:#fff;border:1px solid var(--line);border-radius:16px;margin-bottom:12px;overflow:hidden}.topic-group>h4{font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);padding:15px 18px;margin:0;background:#f6f9f9;border-bottom:1px solid var(--line)}.topic-item{display:grid;grid-template-columns:36px 1fr auto;align-items:center;gap:12px;padding:15px 17px;border-bottom:1px solid #edf1f3;text-decoration:none;transition:.18s}.topic-item:last-child{border-bottom:0}.topic-item:hover{background:#f4faf9}.topic-num{font-size:10px;color:#8aa0af}.topic-item strong{display:block;font-size:13px;color:var(--navy)}.topic-item small{font-size:10px;color:var(--muted)}.topic-status{font-size:9px;text-transform:uppercase;letter-spacing:.06em;font-weight:800;color:#8799a7;padding:5px 7px;border-radius:999px;background:#eef2f4}.topic-status.live{color:#177b6e;background:var(--teal-light)}.topic-item.disabled{cursor:default}.topic-item.disabled:hover{background:#fff}.empty-state{text-align:center;padding:70px 20px}.empty-state>span{font-size:50px;color:#b8c8ce}.empty-state h3{margin:10px 0}.empty-state p{color:var(--muted)}.test-info-section{background:var(--cream)}.test-info-grid{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:center}.test-info-grid>div>p:last-child{color:var(--muted)}.score-scale{display:grid;grid-template-columns:repeat(4,1fr);border-radius:18px;overflow:hidden;border:1px solid #d7ddd9}.score-scale span{padding:20px 8px;text-align:center;background:#fff;font-size:10px;color:var(--muted);border-right:1px solid #d7ddd9}.score-scale span:last-child{border:0}.score-scale small{display:block;font-size:20px;color:var(--navy);font-weight:800;margin-top:7px}
.lesson-shell{padding-top:32px;padding-bottom:100px}.breadcrumbs{display:flex;gap:9px;align-items:center;font-size:11px;color:var(--muted);margin:10px 0 32px}.breadcrumbs a{text-decoration:none;color:var(--teal)}.lesson-header{display:flex;justify-content:space-between;gap:40px;padding-bottom:36px;border-bottom:1px solid var(--line)}.lesson-header h1{font-size:clamp(38px,5vw,60px);max-width:820px;margin:16px 0 14px}.lesson-header p{max-width:740px;color:var(--muted);margin:0}.lesson-badges{display:flex;flex-wrap:wrap;gap:7px}.lesson-badges span{font-size:9px;text-transform:uppercase;letter-spacing:.09em;font-weight:800;background:#edf2f3;color:#607689;padding:6px 9px;border-radius:999px}.lesson-badges .interactive-badge{background:var(--teal-light);color:#16786c}.lesson-index{width:86px;height:86px;border:1px solid var(--line);border-radius:50%;display:flex;flex-direction:column;justify-content:center;text-align:center;color:var(--muted);font-size:10px;flex:none}.lesson-index strong{font-size:20px;color:var(--navy)}.lesson-layout{display:grid;grid-template-columns:220px minmax(0,760px);gap:66px;align-items:start;padding-top:42px}.lesson-aside{position:sticky;top:112px}.lesson-aside nav{display:flex;flex-direction:column;border-left:1px solid var(--line);padding-left:17px}.lesson-aside nav strong{font-size:10px;text-transform:uppercase;letter-spacing:.11em;color:var(--navy);margin-bottom:11px}.lesson-aside nav a{text-decoration:none;color:var(--muted);font-size:11px;padding:7px 0}.lesson-aside nav a:hover{color:var(--teal)}.progress-note{margin-top:24px;padding:16px;background:#f1f7f6;border-radius:12px}.progress-note span{font-size:10px;font-weight:800;color:var(--teal)}.progress-note p{font-size:10px;color:var(--muted);margin:5px 0 0}.lesson-content{min-width:0}.lesson-section{padding:40px 0;border-bottom:1px solid var(--line);scroll-margin-top:100px}.lesson-section:first-child{padding-top:4px}.lesson-section h2{font-size:29px;letter-spacing:-.025em;margin-bottom:18px}.lesson-section p,.lesson-section li{color:#526a7d;font-size:15px}.outcomes{background:var(--navy);padding:27px 31px!important;border:0;border-radius:18px}.outcomes h2{color:#fff;font-size:17px}.outcomes ul{margin:0;padding-left:20px;display:grid;gap:5px}.outcomes li{color:#d0dee7;font-size:12px}.section-kicker{font-size:9px!important;text-transform:uppercase;letter-spacing:.15em;color:var(--teal)!important;font-weight:800;margin-bottom:12px}.formula-display{padding:22px;margin:22px 0;background:#f2f7f7;border-radius:14px;text-align:center;color:var(--navy);font-size:20px;overflow-x:auto}.callout{display:grid;grid-template-columns:28px 1fr;gap:12px;padding:17px;background:#fff8eb;border:1px solid #f2dfbf;border-radius:13px;margin-top:20px}.callout span{display:grid;place-items:center;width:26px;height:26px;background:var(--orange);border-radius:8px;color:var(--navy);font-weight:800}.callout p{font-size:12px;margin:0;color:#765d3d}.explorer{margin-top:22px;padding:24px;border:1px solid var(--line);border-radius:18px;background:#fff;box-shadow:0 14px 40px rgba(16,42,67,.055)}.explorer-grid{display:grid;grid-template-columns:240px 1fr;gap:24px;align-items:center}.controls{display:grid;gap:17px}.control-row label{display:flex;justify-content:space-between;font-size:11px;font-weight:700;color:var(--navy);margin-bottom:6px}.control-row output{color:var(--teal);font-weight:800}.control-row input[type=range]{width:100%;accent-color:var(--teal)}.live-equation{padding:14px;border-radius:11px;background:var(--navy);color:#fff;text-align:center;overflow-x:auto}.live-stats{display:grid;grid-template-columns:1fr 1fr;gap:8px}.live-stat{padding:10px;background:#f1f6f6;border-radius:9px;font-size:10px;color:var(--muted)}.live-stat strong{display:block;color:var(--navy);font-size:13px}.graph-canvas,.coordinate-canvas,.space-canvas{width:100%;height:auto;background:#fbfdfd;border-radius:13px;border:1px solid #edf1f2}.triangle-stage{position:relative;min-height:270px;display:grid;place-items:center}.triangle-stage svg{width:100%;max-height:280px}.explorer-tabs{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:15px}.explorer-tabs button{border:1px solid var(--line);background:#fff;border-radius:9px;padding:8px 10px;font-size:10px;font-weight:800;cursor:pointer}.explorer-tabs button.active{background:var(--navy);color:#fff}.worked-example{border-left:3px solid var(--teal);padding:5px 0 5px 24px}.worked-example h3{font-size:20px}.solution-steps{counter-reset:steps;display:grid;gap:13px;margin-top:20px}.solution-step{display:grid;grid-template-columns:28px 1fr;gap:12px}.solution-step:before{counter-increment:steps;content:counter(steps);display:grid;place-items:center;width:25px;height:25px;border-radius:50%;background:var(--teal-light);color:var(--teal);font-size:10px;font-weight:800}.solution-step p{font-size:13px;margin:0}.summary-card{margin-top:35px;padding:28px!important;border:0;border-radius:17px;background:#eef7f5}.summary-card ul{display:grid;gap:9px;margin:0;padding-left:20px}.summary-card li{font-size:13px}.lesson-actions{display:flex;justify-content:space-between;gap:12px;padding-top:36px}.source-note{font-size:10px;color:var(--muted);padding-top:24px}.source-note a{color:var(--teal)}
.compact-header .close-test{font-size:12px;text-decoration:none;color:var(--muted);font-weight:700}.test-main{min-height:70vh}.test-shell{max-width:900px;padding-top:46px;padding-bottom:100px}.test-heading{display:flex;justify-content:space-between;gap:40px;align-items:flex-start}.test-heading h1{font-size:clamp(35px,5vw,54px);margin:14px 0}.test-heading p{color:var(--muted);max-width:680px}.test-progress{width:96px;height:96px;border-radius:50%;background:var(--navy);color:#fff;display:flex;flex-direction:column;justify-content:center;align-items:center;flex:none}.test-progress span{font-size:18px;font-weight:800}.test-progress small{font-size:9px;color:#9fb6c7;text-transform:uppercase;letter-spacing:.08em}.protection-note{display:flex;gap:13px;padding:17px 19px;border:1px solid #e8dcc8;background:#fffaf1;border-radius:13px;margin:30px 0}.protection-note>span{color:#bd792b}.protection-note p{margin:0;font-size:11px;color:#75634c}.quiz-form{display:grid;gap:16px}.quiz-question{border:1px solid var(--line);background:#fff;border-radius:17px;padding:25px}.question-head{display:flex;gap:18px}.question-number{font-size:10px;font-weight:800;color:var(--teal);width:24px;flex:none}.question-text{font-size:15px;font-weight:700;color:var(--navy);margin:0 0 18px}.answer-options{display:grid;grid-template-columns:1fr 1fr;gap:9px}.answer-option{position:relative}.answer-option input{position:absolute;opacity:0;pointer-events:none}.answer-option label{display:flex;align-items:center;gap:11px;min-height:49px;border:1px solid var(--line);border-radius:11px;padding:10px 13px;cursor:pointer;font-size:12px;color:#425a6f;transition:.15s}.answer-option label:before{content:"";width:15px;height:15px;border:1.5px solid #9bafb9;border-radius:50%;flex:none}.answer-option input:checked+label{border-color:var(--teal);background:#f0faf8;color:var(--navy)}.answer-option input:checked+label:before{border:4px solid var(--teal)}.answer-option input:focus-visible+label{outline:3px solid rgba(33,166,148,.25)}.quiz-question.is-correct{border-color:#77c6b3;background:#f3fbf8}.quiz-question.is-wrong{border-color:#dfa6a6;background:#fff8f8}.quiz-question.locked .answer-option label{cursor:default}.answer-option.correct-answer label{border-color:var(--green)!important;background:#eaf8f3!important}.answer-option.user-wrong label{border-color:var(--red)!important;background:#fff0f0!important}.answer-explanation{font-size:11px;color:var(--muted);margin:14px 0 0;padding:12px 14px;background:rgba(255,255,255,.8);border-radius:9px}.test-submit{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:28px 0}.test-submit p{font-size:11px;color:var(--muted);margin:0}.test-submit button:disabled{opacity:.5;cursor:not-allowed;transform:none}.test-results{margin-top:12px;padding:34px;border-radius:20px;background:var(--navy);color:#d4e1e9}.test-results h2{color:#fff;font-size:29px}.result-grid{display:grid;grid-template-columns:150px 1fr;gap:30px;align-items:center}.grade-circle{width:140px;height:140px;border-radius:50%;display:flex;flex-direction:column;justify-content:center;align-items:center;background:var(--teal);color:#fff}.grade-circle strong{font-size:52px;line-height:1}.grade-circle span{font-size:9px;text-transform:uppercase;letter-spacing:.1em}.result-copy p{font-size:13px}.result-meta{display:flex;gap:20px;font-size:10px;color:#9fb6c7}.result-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px}.result-actions .button{min-height:44px}.result-actions .ghost{color:#fff;border-color:rgba(255,255,255,.3);background:transparent}.protected-math{-webkit-user-select:none;user-select:none}
.sources-section{background:#f8faf9}.source-group{margin-bottom:55px}.source-group-title{display:flex;gap:18px;align-items:center;margin-bottom:18px}.source-group-title>span{display:grid;place-items:center;width:54px;height:54px;border-radius:16px;background:var(--navy);color:#fff;font-size:17px;font-weight:800}.source-group-title h2{margin:0;font-size:24px}.source-group-title p{margin:3px 0 0;font-size:11px;color:var(--muted)}.source-list{display:grid;gap:10px}.source-list>a{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:22px;border:1px solid var(--line);background:#fff;border-radius:15px;text-decoration:none;transition:.2s}.source-list>a:hover{transform:translateX(4px);border-color:#9ccfc8}.source-list span{display:block;font-size:9px;color:var(--teal);text-transform:uppercase;letter-spacing:.11em;font-weight:800}.source-list strong{display:block;font-size:14px;color:var(--navy);margin:3px 0}.source-list small{display:block;color:var(--muted);font-size:10px}.source-list b{color:var(--teal)}.source-group.official .source-group-title>span{background:var(--teal);font-size:11px}.integrity-card{padding:32px;border-radius:20px;background:var(--cream);margin-top:75px}.integrity-card h2{font-size:23px}.integrity-card p{color:var(--muted);font-size:14px;margin:0}
.reveal{opacity:0;transform:translateY(18px);transition:opacity .65s ease,transform .65s ease}.reveal.visible{opacity:1;transform:none}.delay-1{transition-delay:.08s}.delay-2{transition-delay:.16s}.delay-3{transition-delay:.24s}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.reveal{opacity:1;transform:none;transition:none}.button,.grade-card,.source-list>a{transition:none}}
@media (max-width:980px){.hero{min-height:auto;padding-top:55px}.hero-grid{grid-template-columns:1fr .75fr;gap:30px}.about-grid{gap:45px}.flow-grid{grid-template-columns:1fr 1fr}.lesson-layout{grid-template-columns:1fr}.lesson-aside{display:none}.catalog-controls{grid-template-columns:1fr 1fr}.catalog-search{grid-column:1/-1}.test-info-grid{gap:40px}.explorer-grid{grid-template-columns:210px 1fr}}
@media (max-width:760px){.container{width:min(calc(100% - 28px),var(--container))}.site-header{height:70px}.site-nav{display:none;position:absolute;left:14px;right:14px;top:64px;background:#fff;padding:10px;border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);flex-direction:column;align-items:stretch}.site-nav.open{display:flex}.site-nav a{padding:12px}.menu-button{display:block}.brand-mark{width:38px;height:38px}.hero{padding:46px 0 65px}.hero-grid{grid-template-columns:1fr}.hero-copy{text-align:left}.hero-visual{grid-row:1}.portrait-card{width:min(78vw,370px)}.orbit-one{left:-10px}.orbit-two{right:-9px}.hero-facts{margin-top:35px}.section{padding:75px 0}.section-heading{display:block}.section-heading>p{margin-top:18px}.grade-grid,.about-grid,.subject-columns,.test-info-grid{grid-template-columns:1fr}.grade-card{min-height:270px}.grade-number{font-size:70px}.about-grid{gap:35px}.flow-grid{grid-template-columns:1fr 1fr}.cta-card{padding:38px 28px;display:block}.cta-card .button{margin-top:24px}.footer-grid{grid-template-columns:1fr 1fr}.footer-grid>div:first-child{grid-column:1/-1}.page-hero{padding:62px 0}.catalog-controls{grid-template-columns:1fr;gap:16px}.catalog-search{grid-column:auto}.catalog-summary{margin-top:38px}.score-scale{grid-template-columns:1fr 1fr}.lesson-header{display:block}.lesson-index{display:none}.lesson-shell{padding-top:20px}.explorer-grid{grid-template-columns:1fr}.controls{order:2}.answer-options{grid-template-columns:1fr}.test-heading{display:block}.test-progress{width:auto;height:auto;border-radius:12px;display:inline-flex;flex-direction:row;gap:6px;padding:10px 15px}.result-grid{grid-template-columns:1fr}.grade-circle{margin:auto}.result-copy{text-align:center}.result-meta,.result-actions{justify-content:center}}
@media (max-width:480px){h1{font-size:40px}.lead{font-size:16px}.portrait-caption{font-size:9px}.hero-facts li{min-width:0;flex:1;padding:0 12px}.hero-facts strong{font-size:23px}.hero-facts span{font-size:8px}.grade-card{padding:27px}.flow-grid{grid-template-columns:1fr}.timeline-card{padding:26px}.footer-grid{grid-template-columns:1fr}.footer-grid>div:first-child{grid-column:auto}.footer-bottom{flex-direction:column}.catalog-controls{padding:15px}.segmented.wide{display:grid;grid-template-columns:repeat(3,1fr)}.topic-item{grid-template-columns:27px 1fr}.topic-status{grid-column:2}.lesson-actions{flex-direction:column}.lesson-actions .button{width:100%}.explorer{padding:15px}.quiz-question{padding:19px}.test-results{padding:25px}.source-list>a{padding:18px}.source-group-title>span{width:46px;height:46px}}
.brand-mark{font-size:0!important;color:transparent;background-color:var(--navy);background-image:url('../../favicon.svg');background-repeat:no-repeat;background-position:center;background-size:100% 100%}.footer-brand .brand-mark{background-color:#183b57;background-image:url('../../favicon.svg')}