@font-face{font-family:"Plus Jakarta Sans";src:url("assets/fonts/PlusJakartaSans.ttf") format("truetype");font-weight:200 800;font-display:swap}
@font-face{font-family:"DM Sans";src:url("assets/fonts/DMSans.ttf") format("truetype");font-weight:100 1000;font-display:swap}
:root{--paper:#fbfcfe;--white:#fff;--ink:#1a2540;--blue:#234cd4;--yellow:#f3cd44;--green:#146c58;--muted:#52617a;--line:#d7deea;--soft:#edf2fd;--error:#a61c32;--display:"Plus Jakarta Sans","Trebuchet MS",sans-serif;--body:"DM Sans",Arial,sans-serif;--pad:clamp(20px,4.8vw,72px);--header:88px}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header) + 24px)}
body{margin:0;background:var(--paper);color:var(--ink);font:400 17px/1.65 var(--body);-webkit-font-smoothing:antialiased}
body,h1,h2,h3,p,figure,fieldset{margin:0}
button,input,select{font:inherit}
button,a,input,summary{-webkit-tap-highlight-color:transparent}
button,summary{cursor:pointer}
button{color:inherit}
button:disabled{cursor:default}
a{color:inherit;text-underline-offset:5px}
button,a,input,summary,select{touch-action:manipulation}
a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible,select:focus-visible,[tabindex]:focus-visible{outline:3px solid var(--blue);outline-offset:5px}
[hidden]{display:none!important}
h1,h2,h3,.brand,.button,.subject-tabs,.math-readout{font-family:var(--display)}
h1,h2,h3{font-weight:800;letter-spacing:-.055em;line-height:1.13;text-wrap:balance}
h1{font-size:clamp(44px,4.7vw,72px)}
h2{font-size:clamp(34px,3.4vw,52px)}
h3{font-size:25px;letter-spacing:-.04em}
img,svg{display:block;max-width:100%;height:auto}
fieldset{padding:0;border:0;min-width:0}
legend{padding:0}
.wrap{width:min(100%,1392px);padding-inline:var(--pad);margin-inline:auto}
.hero>*,.section-heading>*,.subject-panel>*,.guide-layout>*,.parents-layout>*,.faq-section>*,.lesson-layout>*{min-width:0}
.section{padding-block:100px}
.section-heading{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:end;margin-bottom:52px}
.section-heading>p{max-width:46ch;color:var(--muted);font-size:18px}
.button{display:inline-flex;gap:28px;align-items:center;justify-content:center;min-height:56px;padding:14px 23px;background:var(--blue);color:#fff;border:2px solid var(--ink);border-radius:9px;box-shadow:0 4px 0 var(--ink);text-decoration:none;font-size:15px;font-weight:800;line-height:1.4;transition:transform .15s,box-shadow .15s,background .15s}
.button>span[aria-hidden]{font:500 23px/1 var(--body)}
.button-small{min-height:46px;padding:10px 17px;gap:20px;font-size:13px;box-shadow:0 3px 0 var(--ink)}
.button-yellow{background:var(--yellow);color:var(--ink)}
.button-white{background:white;color:var(--ink)}
.button:active{transform:translateY(4px);box-shadow:none}
.button:disabled{opacity:.55;box-shadow:none;transform:none}
.text-link{display:inline-flex;align-items:center;gap:16px;min-height:44px;font-size:15px;font-weight:700;text-decoration:underline;text-decoration-thickness:1px}
.text-link>span{font-size:22px}
.quiet-note{color:var(--muted);font-size:13px;line-height:1.6}
.skip-link{position:fixed;left:20px;top:-100px;background:var(--yellow);border:2px solid var(--ink);padding:12px 20px;z-index:100}
.skip-link:focus{top:12px}
.site-header{height:var(--header);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20;background:rgba(251,252,254,.97)}
.header-inner{height:100%;width:min(100%,1392px);margin:auto;padding-inline:var(--pad);display:flex;align-items:center;justify-content:space-between;gap:24px}
.brand{display:inline-flex;gap:11px;align-items:center;text-decoration:none;font-size:21px;letter-spacing:-.055em;font-weight:800;white-space:nowrap;min-height:44px;flex:none}
.brand img{width:30px;flex:none}
.site-header nav{display:flex;align-items:center;gap:28px}
.site-header nav>a:not(.button){min-height:44px;display:inline-flex;align-items:center;text-decoration:none;font-size:14px;font-weight:600}
.menu-toggle{display:none;align-items:center;gap:12px;border:1px solid var(--ink);border-radius:6px;background:white;min-height:44px;padding:8px 12px}
.hero{display:grid;grid-template-columns:1.05fr 1fr;gap:70px;align-items:center;padding-block:82px 70px}
.audience-label{font-size:13px;font-weight:600;display:flex;gap:12px;align-items:center;margin-bottom:24px}
.mini-shapes{display:flex;gap:3px;align-items:center}
.mini-shapes i{width:10px;height:10px;background:var(--blue);display:block}
.mini-shapes i:nth-child(2){background:var(--yellow);border-radius:50%}
.mini-shapes i:nth-child(3){background:var(--green);clip-path:polygon(50% 0,100% 100%,0 100%)}
.hero-description{font-size:18px;max-width:40ch;color:var(--muted);margin-top:25px}
.hero-actions{display:flex;align-items:center;flex-wrap:wrap;gap:20px;margin-top:30px;margin-bottom:17px}
.hero-demo{position:relative;padding:17px 0 0;max-width:530px;width:100%;justify-self:end}
.demo-sticker{position:absolute;top:-27px;right:9px;z-index:2;transform:rotate(7deg);background:var(--yellow);border:2px solid var(--ink);border-radius:3px;padding:10px 18px;font-size:12px;line-height:1.4;font-weight:700;box-shadow:3px 3px 0 var(--ink)}
.math-window{border:2px solid var(--ink);border-radius:16px;box-shadow:8px 8px 0 var(--ink);background:white;overflow:hidden}
.window-bar{background:var(--soft);border-bottom:2px solid var(--ink);padding:17px 23px;display:flex;justify-content:space-between;align-items:center;font-size:12px;font-weight:600;gap:12px}
.window-bar>span:first-child{display:flex;align-items:center;gap:9px}
.status-dot{width:8px;height:8px;background:var(--green);border-radius:50%;display:block}
.window-dots{font-size:8px;letter-spacing:3px}
.window-content{padding:26px 32px 24px}
.small-label{font-size:12px;color:var(--muted);font-weight:500}
.window-content h2{font-size:23px;margin-top:6px;letter-spacing:-.04em}
.hero-equation{display:flex;justify-content:center;align-items:center;gap:15px;font:800 clamp(30px,3.4vw,49px)/1 var(--display);margin:26px 0 20px}
.hero-equation>span{display:grid;place-items:center}
.unknown-box{width:76px;height:78px;background:var(--blue);border:2px solid var(--ink);color:white;border-radius:8px;box-shadow:0 4px 0 var(--ink);transition:background .2s}
.unknown-box.is-correct{background:var(--green)}
.number-block{width:67px;height:73px;background:var(--yellow);border:2px solid var(--ink);border-radius:8px}
.number-result{min-width:42px}
.number-line{border-top:2px solid var(--line);display:flex;justify-content:space-between;align-items:start;margin:0 15px 24px;height:15px;font-size:10px;color:var(--muted);position:relative;padding-top:3px}
.number-line i{display:block;width:1px;height:7px;background:var(--line);margin-top:-4px}
.hero-answer legend{font-size:12px;color:var(--muted);margin-bottom:10px}
.answer-options{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}
.answer-options button{min-height:46px;border:1.5px solid var(--line);border-radius:7px;background:white;font:700 19px var(--display)}
.answer-options button[aria-pressed=true]{border-color:var(--blue);background:var(--soft);box-shadow:inset 0 -3px 0 var(--blue)}
.answer-options button.correct{border-color:var(--green);color:var(--green);background:#eaf4ef;box-shadow:inset 0 -3px 0 var(--green)}
.guide-message{display:grid;grid-template-columns:40px 1fr;align-items:center;gap:12px;background:#edf5f1;border-radius:8px;padding:12px 14px;margin-top:20px;min-height:81px}
.guide-message img{width:40px}
.guide-message p{font-size:13px;font-weight:500;line-height:1.55}
.handwritten-note{font-size:12px;color:var(--muted);text-align:center;margin-top:20px}
.handwritten-note span{display:inline-block;font-size:23px;margin-right:5px;color:var(--ink)}
.subject-strip{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));padding-bottom:48px;gap:24px}
.subject-strip>a{border-top:1px solid var(--line);padding-top:21px;text-decoration:none;display:flex;align-items:center;gap:11px;font-weight:700;font-size:14px}
.subject-strip small{display:block;font-size:11px;font-weight:400;color:var(--muted);margin-top:2px;white-space:nowrap}
.subject-symbol{width:42px;height:42px;display:grid;place-items:center;font:700 26px/1 var(--display);flex:none;border:1.5px solid var(--ink);border-radius:9px}
.symbol-yellow{background:var(--yellow)}.symbol-blue{background:var(--blue);color:white}.symbol-green{background:var(--green);color:white}.symbol-paper{background:var(--soft)}
.strip-arrow{margin-left:auto;font-size:19px;font-weight:400}
.method-section{background:var(--yellow);border-block:2px solid var(--ink);padding-block:76px}
.method-section .section-heading>p{color:var(--ink)}
.method-steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:32px;list-style:none;padding:0;margin:0}
.method-steps li{border-top:1.5px solid var(--ink);padding-top:18px}
.step-number{font:600 14px var(--display);display:block;margin-bottom:28px}
.method-steps h3{font-size:22px;margin-bottom:12px}
.method-steps p{font-size:15px;line-height:1.7;max-width:30ch}
.subject-tabs{display:flex;border-bottom:2px solid var(--ink);gap:8px;margin-bottom:40px}
.subject-tabs button{flex:1;background:transparent;border:0;border-radius:8px 8px 0 0;font-weight:700;font-size:16px;padding:17px 12px;min-height:58px}
.subject-tabs button[aria-selected=true]{color:white;background:var(--ink)}
.subject-panel{display:grid;grid-template-columns:.85fr 1.15fr;gap:70px;align-items:center;min-height:432px}
.subject-panel:focus-visible{outline-offset:10px}
.subject-copy h3{font-size:35px;margin:12px 0 20px}
.subject-copy>p{color:var(--muted);max-width:39ch;font-size:16px}
.subject-kicker{color:var(--green);font-size:13px;font-weight:600}
.topic-list{list-style:none;margin:24px 0;padding:0;display:flex;flex-wrap:wrap;gap:8px}
.topic-list li{background:#eef1f6;border:1px solid var(--line);border-radius:5px;font-size:11px;padding:5px 9px}
.math-playground{border:2px solid var(--ink);border-radius:14px;background:var(--soft);padding:32px;min-height:432px;display:flex;flex-direction:column;justify-content:center;align-items:center;position:relative;overflow:hidden}
.fraction-visual{display:grid;grid-template-columns:repeat(2,1fr);width:186px;height:186px;gap:6px;transform:rotate(-7deg);margin:6px 0 20px}
.fraction-piece{background:var(--yellow);border:2px solid var(--ink);border-radius:5px;transition:background .2s}
.fraction-piece.filled{background:var(--blue)}
.math-readout{font-size:31px;font-weight:800;letter-spacing:-.04em;margin:8px 0 21px;text-align:center}
.range-control{width:100%;max-width:320px}
.range-control label{display:flex;justify-content:space-between;font-size:12px;font-weight:600;gap:12px}
.range-control output{color:var(--blue)}
input[type=range]{width:100%;min-height:44px;margin:0;accent-color:var(--blue);cursor:pointer}
.model-note{font-size:12px;color:var(--muted);text-align:center;margin-top:10px;max-width:44ch}
.explore-footnote{font-size:13px;color:var(--muted);margin-top:27px;text-align:right}
.algebra-model{display:flex;align-items:center;gap:24px;width:100%;max-width:360px;min-height:190px}
.algebra-side{display:grid;gap:14px;flex:1}
.algebra-side span{min-height:64px;display:grid;place-items:center;background:var(--blue);color:white;border:2px solid var(--ink);border-radius:6px;font:800 26px var(--display)}
.gold-side span{background:var(--yellow);color:var(--ink)}
.algebra-model>b{font-size:35px}
.model-controls{display:flex;gap:16px;align-items:center}
.model-controls .button{font-size:12px;min-height:48px;padding:10px 16px}
.icon-button{border:1px solid var(--ink);border-radius:6px;background:white;min-width:44px;min-height:44px;font-size:24px}
.rectangle-wrap{height:206px;width:100%;display:flex;align-items:center;justify-content:center;gap:12px}
.rectangle-grid{display:grid;grid-template-columns:repeat(4,1fr);width:176px;gap:2px;border:2px solid var(--ink);padding:2px;background:var(--ink);transition:width .2s}
.rectangle-grid span{aspect-ratio:1;background:var(--yellow)}
.rectangle-height{font-size:12px;white-space:nowrap}
.geometry-readout,.trig-readout{display:flex;justify-content:center;gap:28px;font-size:12px;text-align:center;margin-bottom:21px;flex-wrap:wrap}
.geometry-readout strong{display:block;font-size:23px;font-family:var(--display);letter-spacing:-.03em}
.unit-circle{width:100%;max-width:355px;height:227px}
.unit-circle text{fill:var(--muted);font:13px var(--body)}
.axis-line{stroke:#a9b5cd;stroke-width:1}
.circle-line{stroke:#a9b5cd;stroke-width:1.5;fill:none}
.cosine-line{stroke:var(--green);stroke-width:5}.sine-line{stroke:var(--blue);stroke-width:5}
.radius-line{stroke:var(--ink);stroke-width:2.5}#trig-dot{fill:var(--yellow);stroke:var(--ink);stroke-width:2}
.trig-readout{margin-top:6px;gap:22px;font-size:13px}.trig-readout strong{font-size:20px}
.guide-section{background:#edf2fa;border-block:1px solid var(--line)}
.guide-layout{display:grid;grid-template-columns:1fr 1fr;gap:100px;align-items:center}
.guide-stage{position:relative;min-height:450px;display:flex;flex-direction:column;align-items:center;justify-content:center;isolation:isolate}
.guide-stage-grid{position:absolute;width:330px;height:330px;top:8px;border-radius:50%;background-image:linear-gradient(#cdd6e980 1px,transparent 1px),linear-gradient(90deg,#cdd6e980 1px,transparent 1px);background-size:26px 26px;z-index:-1;mask-image:radial-gradient(black 45%,transparent 70%)}
.pip-large{width:200px;height:220px;transform-origin:50% 100%}
.pip-large.is-speaking{animation:pip-speak 1.8s ease-in-out infinite}
@keyframes pip-speak{0%,100%{transform:rotate(-3deg)}50%{transform:rotate(3deg) translateY(-4px)}}
.guide-name{font-size:12px;font-weight:700;margin:4px 0 25px}
.pip-bubble{background:white;border:2px solid var(--ink);border-radius:16px;box-shadow:5px 5px 0 var(--ink);padding:23px 26px;width:100%;max-width:387px;position:relative}
.pip-bubble::before{content:"";position:absolute;width:14px;height:14px;background:white;border-left:2px solid var(--ink);border-top:2px solid var(--ink);transform:rotate(45deg);top:-9px;left:calc(50% - 7px)}
.pip-bubble>p:first-child{font-size:17px;line-height:1.55;font-weight:500}
.voice-button{display:flex;gap:9px;align-items:center;background:transparent;border:0;padding:4px 0;min-height:44px;color:var(--blue);font-size:13px;font-weight:700;margin-top:8px}
.voice-button span{font-size:20px}
.voice-status{font-size:11px;color:var(--muted);line-height:1.5}
.guide-copy>p{font-size:16px;color:var(--muted);margin-top:24px;max-width:48ch}
.hint-preview{list-style:none;margin:26px 0;padding:0;display:grid;gap:22px}
.hint-preview li{display:flex;gap:15px;align-items:start}
.hint-preview li>span{display:grid;place-items:center;background:white;border:1.5px solid var(--ink);border-radius:50%;width:29px;height:29px;flex:none;font-size:12px;font-weight:700}
.hint-preview h3{font-size:16px;letter-spacing:-.025em;margin:2px 0 5px}
.hint-preview p{font-size:14px;color:var(--muted);max-width:38ch;line-height:1.6}
.guide-copy>p.quiet-note{font-size:12px;margin-bottom:14px}
.parents-section{background:var(--green);color:white;border-bottom:2px solid var(--ink)}
.parents-layout{display:grid;grid-template-columns:1fr 1fr;gap:100px;align-items:center}
.section-context{font-size:13px;margin-bottom:18px;color:#d3ebe3}
.parents-copy>p:not(.section-context){max-width:43ch;color:#e0f0ea;margin-top:25px;font-size:16px}
.parent-benefits{list-style:none;margin:28px 0 32px;padding:0;display:grid;gap:12px;font-size:14px}
.parent-benefits span{color:var(--yellow);margin-right:10px;font-weight:700}
.parent-report{background:white;color:var(--ink);border:2px solid var(--ink);border-radius:16px;box-shadow:8px 8px 0 #0d493b;padding:30px;transform:rotate(2deg)}
.report-heading{display:flex;align-items:center;gap:10px;font-size:13px;font-weight:700;padding-bottom:24px;border-bottom:1px solid var(--line)}
.example-badge{margin-left:auto;color:var(--muted);background:#eef1f6;border:1px solid var(--line);border-radius:5px;font-size:10px;padding:3px 7px;font-weight:500}
.parent-report h3{font-size:29px;margin:25px 0}
.report-row{display:grid;grid-template-columns:1fr;gap:6px;padding:15px 0;border-top:1px solid var(--line);font-size:12px}
.report-row>span{color:var(--muted)}
.report-row strong{display:flex;align-items:center;font-size:14px;gap:9px;font-weight:600}
.report-dot{width:8px;height:8px;border-radius:50%;display:inline-block}
.yellow-dot{background:var(--yellow);border:1px solid #8d721a}.green-dot{background:var(--green)}
.report-reflection{margin-top:17px;background:#edf5f1;border-radius:8px;padding:16px}
.report-reflection p{font-size:16px;margin-top:7px}
.report-note{font-size:11px;color:var(--muted);margin-top:18px;line-height:1.6}
.faq-section{display:grid;grid-template-columns:.8fr 1.2fr;gap:90px}
.faq-heading>p{margin-top:20px;font-size:15px;color:var(--muted)}
.faq-list details{border-bottom:1px solid var(--line)}
.faq-list details:first-child{border-top:1px solid var(--line)}
.faq-list summary{display:flex;align-items:center;justify-content:space-between;gap:22px;list-style:none;padding:21px 0;min-height:70px;font-size:16px;font-weight:600;line-height:1.45}
.faq-list summary::-webkit-details-marker{display:none}
.faq-list summary span{font-size:24px;font-weight:400;flex:none;transition:transform .15s}
.faq-list details[open] summary span{transform:rotate(45deg)}
.faq-list details>p{padding:0 28px 22px 0;font-size:15px;color:var(--muted);max-width:65ch}
.final-cta{background:var(--blue);color:white;border-block:2px solid var(--ink);padding-block:80px;overflow:hidden}
.cta-inner{display:grid;grid-template-columns:1.4fr 1fr;gap:70px;align-items:center}
.cta-inner h2{font-size:clamp(34px,3.7vw,55px);max-width:20ch}
.cta-inner p{font-size:16px;margin:22px 0 28px;color:#e1e9ff}
.cta-inner p.cta-note{font-size:12px;margin:20px 0 0}
.cta-composition{width:320px;height:270px;position:relative;margin:auto;transform:rotate(-8deg)}
.cta-square{width:140px;height:140px;position:absolute;left:0;top:0;border:3px solid var(--ink);background:var(--paper);color:var(--blue);display:grid;place-items:center;border-radius:12px;font:800 90px/1 var(--display);box-shadow:7px 7px 0 var(--ink)}
.cta-circle{width:140px;height:140px;position:absolute;right:0;bottom:0;border:3px solid var(--ink);background:var(--yellow);color:var(--ink);display:grid;place-items:center;border-radius:50%;font:800 90px/1 var(--display);box-shadow:7px 7px 0 var(--ink)}
.cta-triangle{position:absolute;left:15px;bottom:0;width:116px;height:100px;background:#86c8b0;clip-path:polygon(50% 0,100% 100%,0 100%)}
.cta-spark{position:absolute;right:17px;top:5px;font-size:100px;line-height:1;color:var(--yellow)}
.site-footer{padding-block:35px 28px}
.footer-top{display:flex;align-items:center;gap:28px;padding-bottom:28px;border-bottom:1px solid var(--line)}
.footer-top>p{font-size:13px;color:var(--muted)}
.footer-top>a:last-child{margin-left:auto;font-size:12px;min-height:44px;display:flex;align-items:center}
.footer-bottom{display:flex;align-items:start;gap:32px;font-size:11px;color:var(--muted);padding-top:24px}
.footer-bottom>p{margin-right:auto}
.footer-bottom>a{white-space:nowrap;min-height:44px;display:flex;align-items:start}
.privacy-details{max-width:400px;scroll-margin-top:120px}
.privacy-details summary{min-height:44px}
.privacy-details>p{margin-top:5px}
html:not(.js) .site-header{height:auto;min-height:var(--header)}
html:not(.js) .site-header .header-inner{flex-wrap:wrap;padding-block:14px}
html:not(.js) .site-header nav{flex-wrap:wrap}
.parents-section a:focus-visible,.final-cta a:focus-visible{outline-color:var(--yellow)}
/* The sample lesson is a separate surface, sharing the same visual language. */
.demo-header .demo-exit{font-size:13px;min-height:44px;display:flex;align-items:center;gap:10px}
.lesson-main{max-width:1120px;min-height:calc(100svh - 175px);margin:auto;padding:54px var(--pad) 70px}
.demo-intro{max-width:670px;margin-bottom:33px}
.demo-intro h1{font-size:clamp(34px,4.3vw,52px);margin:9px 0 20px}
.demo-intro>p{font-size:16px;color:var(--muted)}
.demo-intro .audience-label{font-size:13px;color:var(--green);margin:0}
.topic-choices{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.topic-choice{display:grid;grid-template-columns:44px 1fr 20px;gap:18px;align-items:start;border:2px solid var(--line);border-radius:12px;background:white;padding:22px;cursor:pointer}
.topic-choice:has(input:checked){border-color:var(--blue);background:var(--soft);box-shadow:0 3px 0 var(--blue)}
.topic-choice:has(input:focus-visible){outline:3px solid var(--blue);outline-offset:5px}
.topic-choice input{width:18px;height:18px;margin:6px 0 0;accent-color:var(--blue)}
.topic-choice strong{font:800 18px var(--display);display:block;margin:4px 0 7px;letter-spacing:-.04em}
.topic-choice small{font-size:13px;line-height:1.55;display:block;color:var(--muted)}
.topic-choice em{display:block;font-size:11px;font-style:normal;margin-top:9px;color:var(--green)}
.topic-legend{font-size:17px;font-weight:700;margin-bottom:16px}
.demo-form-actions{display:flex;align-items:center;gap:24px;margin-top:30px;flex-wrap:wrap}
.demo-form-actions>p{font-size:12px;color:var(--muted)}
.storage-notice{font-size:12px;color:var(--muted);margin-top:24px;max-width:76ch}
.resume-banner{border:1px solid var(--green);border-radius:8px;background:#edf5f1;padding:18px 22px;margin-bottom:24px;display:flex;align-items:center;gap:20px;flex-wrap:wrap;font-size:14px}
.resume-banner p{margin-right:auto}
.resume-banner button{font-size:13px;background:none;border:0;text-decoration:underline;min-height:44px}
.lesson-topline{display:flex;align-items:center;justify-content:space-between;font-size:12px;color:var(--muted);gap:20px;margin-bottom:32px}
.lesson-progress{display:flex;gap:6px;align-items:center}
.lesson-progress i{width:32px;height:5px;background:var(--line);border-radius:5px}
.lesson-progress i.current{background:var(--blue)}
.lesson-layout{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(220px,.8fr);gap:40px;align-items:start}
.lesson-card{background:white;border:2px solid var(--ink);border-radius:14px;box-shadow:6px 6px 0 var(--ink);padding:32px}
.lesson-card h1{font-size:32px;margin:8px 0 19px}
.lesson-prompt{font-size:17px;line-height:1.7}
.lesson-visual{margin:24px 0;padding:25px;background:var(--soft);border-radius:8px;text-align:center;font:800 31px/1.4 var(--display);letter-spacing:-.04em}
.answer-form label{display:block;font-size:14px;font-weight:700;margin:20px 0 10px}
.answer-field-row{display:flex;align-items:stretch;gap:12px}
.answer-field-row input{min-width:0;width:100%;min-height:52px;border:1.5px solid #75839b;border-radius:7px;padding:10px 14px;flex:1;font-size:18px;background:white}
.answer-field-row input[aria-invalid=true]{border-color:var(--error)}
.answer-field-row .button{min-height:52px;font-size:13px;padding:10px 18px}
.answer-help{font-size:12px;color:var(--muted);margin-top:10px}
.lesson-feedback{font-size:14px;padding:14px 16px;background:var(--soft);border-radius:7px;margin-top:18px}
.lesson-feedback[data-kind=error]{background:#fceef1;color:#86162a}
.lesson-feedback[data-kind=success]{background:#eaf4ef;color:#105541}
.lesson-next{margin-top:23px}
.lesson-tools{margin-top:24px;display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap}
.link-button{padding:4px 0;min-height:44px;border:0;background:none;text-decoration:underline;text-underline-offset:5px;font-size:13px}
.hint-button{min-height:44px;border:1px solid var(--green);color:var(--green);background:#edf5f1;border-radius:7px;padding:9px 13px;font-size:13px;font-weight:600}
.hint-button:disabled{opacity:.65}
.lesson-guide{padding-top:8px}
.lesson-guide>img{width:102px;margin:0 auto 15px}
.lesson-guide h2{font-size:22px;margin-bottom:13px}
.lesson-guide>p{color:var(--muted);font-size:14px}
.hint-history{list-style:none;margin:20px 0 0;padding:0;display:grid;gap:14px}
.hint-history li{padding:15px;background:#edf5f1;border-left:3px solid var(--green);border-radius:0 6px 6px 0;font-size:14px}
.hint-history li strong{display:block;font-size:11px;margin-bottom:7px;color:var(--green)}
.hint-history li p{line-height:1.6}
.sample-summary{max-width:780px}
.summary-results{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:28px 0}
.summary-result{background:white;border:2px solid var(--ink);border-radius:12px;padding:24px}
.summary-result h2{font-size:21px;margin-bottom:15px}
.summary-result .result-outcome{font-size:17px;font-weight:600;color:var(--green);margin-bottom:15px}
.summary-result dl{margin:0;font-size:13px}
.summary-result dl>div{display:flex;justify-content:space-between;border-top:1px solid var(--line);padding:10px 0;gap:16px}
.summary-result dt{color:var(--muted)}.summary-result dd{margin:0;font-weight:600}
.summary-result .solution-note{font-size:13px;padding:15px 0 0;color:var(--muted);border-top:1px solid var(--line)}
.reflection-box{border-left:4px solid var(--yellow);padding:19px 24px;background:var(--soft);margin:24px 0}
.reflection-box h2{font-size:19px;margin-bottom:9px}
.reflection-box p{font-size:14px;color:var(--muted)}
.sample-summary>.quiet-note{max-width:76ch}
.demo-footer{font-size:12px;padding:22px var(--pad);border-top:1px solid var(--line);display:flex;justify-content:center;flex-wrap:wrap;gap:24px;color:var(--muted)}
.exit-dialog{width:min(440px,calc(100% - 40px));border:2px solid var(--ink);border-radius:14px;padding:30px;color:var(--ink);background:white;box-shadow:6px 6px 0 var(--ink)}
.exit-dialog::backdrop{background:#1a254080}
.exit-dialog h2{font-size:25px;margin-bottom:17px}.exit-dialog p{font-size:15px;color:var(--muted)}
.exit-dialog .dialog-actions{display:flex;gap:20px;flex-wrap:wrap;margin-top:25px}
.exit-dialog .button{font-size:13px;min-height:48px}
.no-script-lesson{padding:30px;background:white;border:2px solid var(--ink);border-radius:12px;margin:20px 0}
.no-script-lesson h2{font-size:25px;margin-bottom:17px}.no-script-lesson p{margin:14px 0}.no-script-lesson summary{padding:10px 0;min-height:44px;font-weight:600}
@media(hover:hover){.button:not(:disabled):hover{transform:translateY(-2px);box-shadow:0 6px 0 var(--ink)}.button:not(:disabled):active{transform:translateY(4px);box-shadow:none}.site-header nav>a:not(.button):hover,.text-link:hover{text-decoration:underline;text-decoration-thickness:2px}.answer-options button:hover{border-color:var(--blue)}.subject-strip a:hover .strip-arrow{color:var(--blue)}.subject-tabs button:not([aria-selected=true]):hover{background:var(--soft)}.faq-list summary:hover{color:var(--blue)}}
@media(min-width:1600px){.hero{padding-block:102px 88px}.hero h1{font-size:76px}}
@media(max-width:1100px){.hero{gap:38px}.hero h1{font-size:clamp(42px,5vw,58px)}.site-header nav{gap:18px}.site-header nav>a:not(.button){font-size:12px}.brand{font-size:19px}.window-content{padding:26px 24px}.subject-strip{gap:18px}.subject-strip small{font-size:10px}.subject-symbol{width:36px;height:36px;font-size:23px}.strip-arrow{display:none}.section-heading{gap:50px}.subject-panel{gap:45px}.guide-layout,.parents-layout{gap:55px}.faq-section{gap:55px}.hero-actions{gap:14px}.hero-actions .button{padding-inline:18px;font-size:13px}.hero-actions .text-link{font-size:13px}.cta-inner{gap:30px}.cta-composition{transform:scale(.85) rotate(-8deg)}.lesson-layout{gap:28px}}
@media(max-width:820px){:root{--header:76px}.site-header nav{gap:13px}.site-header nav>a:not(.button){font-size:11px}.site-header .button-small{font-size:11px;padding:9px 12px;gap:12px}.brand{font-size:17px;gap:8px}.brand img{width:26px}.hero{padding-block:66px 52px;gap:30px}.hero h1{font-size:42px}.hero-description{font-size:16px}.hero-actions{gap:16px}.hero-demo{padding-top:18px}.window-content{padding:23px 20px}.window-content h2{font-size:20px}.hero-equation{gap:10px}.unknown-box{width:63px;height:68px}.number-block{width:55px;height:62px}.guide-message{padding:10px;gap:8px}.guide-message p{font-size:12px}.handwritten-note{font-size:10px}.audience-label{font-size:11px}.subject-strip{grid-template-columns:1fr 1fr;gap:21px 30px}.subject-strip>a{font-size:14px}.subject-strip small{font-size:12px}.subject-symbol{width:43px;height:43px}.strip-arrow{display:block}.section{padding-block:72px}.method-section{padding-block:62px}.method-steps{gap:24px;grid-template-columns:1fr 1fr}.step-number{margin-bottom:17px}.section-heading{gap:35px;margin-bottom:38px}.section-heading>p{font-size:16px}.subject-panel{gap:30px;grid-template-columns:.9fr 1.1fr}.subject-copy h3{font-size:29px}.math-playground{padding:24px 20px;min-height:420px}.math-readout{font-size:27px}.topic-list{gap:6px}.guide-layout,.parents-layout{gap:36px}.guide-copy h2,.parents-copy h2{font-size:33px}.guide-stage{min-height:400px}.pip-bubble{padding:20px}.guide-stage-grid{width:260px;height:260px}.parent-report{padding:23px;transform:rotate(1deg)}.parent-report h3{font-size:25px}.faq-section{grid-template-columns:.65fr 1fr;gap:35px}.faq-list summary{font-size:14px}.cta-composition{width:270px;transform:scale(.8) rotate(-8deg)}.footer-bottom{gap:24px}.lesson-layout{grid-template-columns:1fr}.lesson-guide{padding:22px;background:#edf2fa;border-radius:12px;display:grid;grid-template-columns:58px 1fr;gap:4px 18px}.lesson-guide>img{grid-row:1/3;width:58px;margin:0}.lesson-guide h2{font-size:20px;margin:0}.hint-history{grid-column:1/-1;margin-top:16px}.topic-choice{padding:18px;gap:12px}.topic-choice strong{font-size:16px}}
@media(max-width:700px){:root{--pad:24px;--header:72px}.site-header .header-inner{gap:15px}.brand{font-size:19px}.brand img{width:29px}.menu-toggle:not([hidden]){display:flex;font-size:12px}.js .site-header nav{display:none;position:absolute;top:calc(var(--header) - 1px);left:0;right:0;background:var(--paper);border-bottom:2px solid var(--ink);padding:18px var(--pad) 26px;box-shadow:0 8px 12px #1a25400a;align-items:stretch;gap:10px}.js .site-header nav.is-open{display:flex;flex-direction:column}.site-header nav>a:not(.button){font-size:15px}.site-header .button-small{font-size:14px;min-height:48px}.hero{grid-template-columns:1fr;padding-block:40px 30px;gap:42px}.hero-copy{max-width:540px}.hero h1{font-size:clamp(43px,8.2vw,58px)}.audience-label{font-size:11px;margin-bottom:22px}.hero-description{font-size:17px;max-width:37ch;margin-top:22px}.hero-actions{gap:17px;margin-top:27px;flex-wrap:wrap}.hero-actions .button{font-size:13px;padding-inline:18px;min-height:54px;gap:18px}.hero-actions .text-link{font-size:12px;gap:8px}.hero-demo{justify-self:center;width:min(100%,480px);padding-right:6px}.demo-sticker{top:-17px;right:17px;font-size:10px;padding:8px 12px}.window-content{padding:24px}.window-content h2{font-size:23px}.hero-equation{gap:17px;font-size:42px;margin-block:25px}.unknown-box{width:72px;height:75px}.number-block{width:64px;height:69px}.guide-message p{font-size:13px}.window-bar{padding:16px 21px;font-size:11px}.handwritten-note{font-size:11px;margin-top:18px}.subject-strip{padding-bottom:36px;gap:17px}.subject-strip>a{font-size:12px;gap:9px;padding-top:15px}.subject-strip small{font-size:10px;white-space:normal;line-height:1.4;margin-top:4px}.subject-strip .strip-arrow{display:none}.subject-symbol{width:35px;height:35px;font-size:22px;border-radius:7px}.section{padding-block:58px}.section-heading{grid-template-columns:1fr;gap:22px;margin-bottom:33px}.section-heading h2{font-size:34px}.section-heading>p{font-size:16px;max-width:45ch}.method-steps{gap:29px 20px}.method-steps h3{font-size:20px}.method-steps p{font-size:14px}.step-number{font-size:12px;margin-bottom:18px}.subject-tabs{gap:4px;margin-bottom:29px;display:grid;grid-template-columns:1fr 1fr;border-bottom:0}.subject-tabs button{font-size:13px;min-height:46px;padding:11px 8px;border:1px solid var(--line);border-radius:7px}.subject-tabs button[aria-selected=true]{border-color:var(--ink)}.subject-panel{grid-template-columns:1fr;gap:27px}.subject-copy h3{font-size:30px;margin:10px 0 17px}.subject-copy>p{max-width:46ch;font-size:15px}.topic-list{margin:20px 0 13px}.math-playground{min-height:402px;padding:28px 23px}.fraction-visual{width:172px;height:172px}.explore-footnote{text-align:left;font-size:12px;margin-top:21px}.guide-layout{grid-template-columns:1fr;gap:38px}.guide-stage{order:2;min-height:390px}.guide-copy h2{font-size:34px}.guide-copy>p{font-size:15px}.hint-preview{gap:20px}.guide-stage-grid{width:330px;max-width:100%;height:300px}.pip-large{width:170px;height:187px}.pip-bubble{max-width:360px}.parents-layout{grid-template-columns:1fr;gap:39px}.parents-copy h2{font-size:35px}.parents-copy>p:not(.section-context){font-size:15px}.parent-benefits{font-size:13px}.parent-report{margin-right:5px;padding:25px;transform:rotate(1deg)}.parent-report h3{font-size:29px}.report-row{grid-template-columns:1fr;gap:7px}.faq-section{grid-template-columns:1fr;gap:30px}.faq-heading>p{font-size:14px;margin-top:15px}.faq-list summary{font-size:15px;padding-block:19px;min-height:64px}.faq-list details>p{font-size:14px;padding-right:0}.final-cta{padding-block:55px}.cta-inner{grid-template-columns:1fr;gap:30px}.cta-inner h2{font-size:35px}.cta-inner p{font-size:15px;margin:20px 0 25px}.cta-composition{display:none}.footer-top{flex-wrap:wrap;gap:14px;padding-bottom:22px}.footer-top>p{width:100%;order:3;font-size:12px}.footer-top>a:last-child{font-size:11px}.footer-bottom{flex-wrap:wrap;gap:12px 25px;font-size:11px}.footer-bottom>p{width:100%;margin-bottom:8px}.privacy-details{max-width:100%}.privacy-details[open]{order:3}.footer-bottom>a{min-height:32px}.privacy-details summary{min-height:32px}.lesson-main{padding-top:35px;padding-bottom:50px}.demo-intro h1{font-size:36px}.demo-intro>p{font-size:15px}.topic-choices{grid-template-columns:1fr}.topic-choice{padding:18px;grid-template-columns:40px 1fr 20px;gap:14px}.topic-choice strong{font-size:17px}.topic-choice small{font-size:13px}.demo-form-actions{gap:20px}.lesson-card{padding:24px 20px}.lesson-card h1{font-size:28px}.lesson-prompt{font-size:16px}.lesson-visual{font-size:28px;padding:22px 14px}.answer-field-row{gap:10px}.answer-field-row .button{padding-inline:14px;font-size:12px}.lesson-topline{margin-bottom:22px;gap:10px;font-size:11px}.lesson-progress i{width:21px}.summary-results{grid-template-columns:1fr}.summary-result{padding:22px}.demo-exit{font-size:12px!important}.demo-header .header-inner{gap:10px}.demo-header .brand{font-size:17px}.lesson-guide{grid-template-columns:48px 1fr;padding:18px}.lesson-guide>img{width:48px}.lesson-guide>p{font-size:13px}.demo-footer{font-size:11px;gap:12px 24px}.resume-banner{padding:16px;gap:10px}.resume-banner p{width:100%}}
@media(max-width:374px){:root{--pad:20px}.hero h1{font-size:41px}.hero-actions{gap:12px}.hero-actions .button{gap:14px;padding-inline:14px;font-size:12px}.hero-actions .text-link{font-size:11px}.quiet-note{font-size:12px}.window-content{padding:23px 20px}.window-content h2{font-size:21px}.hero-equation{gap:14px;font-size:38px}.unknown-box{width:65px;height:69px}.number-block{width:57px;height:63px}.answer-field-row{flex-direction:column}.answer-field-row input{flex:auto}.algebra-model{gap:16px}.math-readout{font-size:25px}.model-controls{gap:10px}.model-controls .button{font-size:11px;padding:10px}.geometry-readout{gap:18px}.trig-readout{gap:14px}.brand{font-size:18px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}
@media print{.site-header,.site-footer,.demo-footer,.lesson-tools,.demo-form-actions,.js-only{display:none!important}.sample-summary{max-width:none}.summary-results{break-inside:avoid}.section{padding-block:30px}body{font-size:12pt}.parent-report{transform:none}}