:root{color-scheme:dark;--bg:#0b1220;--panel:#111d30;--text:#f8fafc;--muted:#9aa9bf;--blue:#668aff;--line:#263349}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:95px}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,-apple-system,BlinkMacSystemFont,'Segoe UI',Arial,sans-serif;-webkit-font-smoothing:antialiased}button,a,input{-webkit-tap-highlight-color:transparent}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #9eb4ff;outline-offset:5px}button{color:inherit}header{height:94px;max-width:1400px;margin:auto;padding:0 52px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #ffffff10}.logo{display:flex;align-items:center;gap:12px;white-space:nowrap}.logo b{font-size:23px;letter-spacing:-.7px}.logo b span{font-weight:400;color:#b6c5df}.logo-mark{display:flex;align-items:center;justify-content:center;font-weight:800;font-size:15px;letter-spacing:-3px;width:42px;height:42px;background:#4265ec;border-radius:12px;transform:rotate(-5deg);padding-right:3px}.logo-mark span{font-size:27px;color:#acbfff}nav{display:flex;gap:32px;color:#b6c0d2;font-size:14px}nav a:hover{color:white}.button{border:1px solid #6f8dff;background:#5274f5;color:white;padding:17px 23px;border-radius:10px;display:inline-flex;justify-content:center;align-items:center;gap:32px;font-size:14px;font-weight:600;transition:background .2s,transform .2s;box-shadow:0 5px 25px #365cea20}.button:hover{background:#6585ff;transform:translateY(-2px)}.button span{font-size:20px;line-height:1}.button.small{padding:12px 20px;background:#182845;border-color:#344669;gap:24px}.hero{min-height:730px;position:relative;overflow:hidden;isolation:isolate;max-width:1600px;margin:auto}.hero-grid{position:absolute;inset:0;z-index:-3;background-image:linear-gradient(#647ca10b 1px,transparent 1px),linear-gradient(90deg,#647ca10b 1px,transparent 1px);background-size:62px 62px;mask-image:linear-gradient(transparent,#000 35%,transparent)}.hero:before{content:'';position:absolute;inset:10% 0 0;z-index:-2;background:radial-gradient(ellipse at 15% 75%,#223c783a,transparent 37%),radial-gradient(ellipse at 85% 60%,#4f388145,transparent 37%)}.hero-copy{position:relative;text-align:center;z-index:3;padding-top:78px;margin:auto;max-width:750px;pointer-events:none}.hero-copy a,.hero-copy button{pointer-events:auto}.eyebrow{font-size:11px;letter-spacing:2px;font-weight:650;color:#a8b9d9;display:flex;align-items:center;gap:9px}.hero .eyebrow,.final-cta .eyebrow{justify-content:center}.dot,.tiny-dot{display:inline-block;background:#83a1ff;width:6px;height:6px;border-radius:50%;box-shadow:0 0 14px #709cff66}.dot{width:7px;height:7px}h1{font-size:clamp(48px,4.6vw,70px);letter-spacing:-3px;line-height:1.13;margin:24px 0}h1 .accent{position:relative}.accent{color:#829cff}h1 .accent:after{content:'';position:absolute;left:8%;right:5%;bottom:-11px;border-top:2px solid #6488fa;transform:rotate(-3deg);border-radius:50%;height:10px}.hero-copy p{font-size:16px;color:#a5b3c9;line-height:1.8;margin:28px 0}.hero-actions{display:flex;justify-content:center;align-items:center;gap:24px}.text-link{font-size:13px;display:flex;align-items:center;gap:9px}.play{width:28px;height:28px;border:1px solid #40516e;display:grid;place-items:center;border-radius:50%}.micro{font-size:10px;color:#8494ae;margin-top:22px}.teacher-portrait{position:absolute;bottom:66px;width:29%;max-width:425px;z-index:1;height:500px;display:flex;align-items:end}.teacher-portrait.left{left:1.5%}.teacher-portrait.right{right:1.5%}.teacher-portrait img{width:100%;height:100%;object-fit:contain;object-position:bottom;mask-image:linear-gradient(#000 74%,transparent 100%);filter:drop-shadow(0 0 35px #4462b31c)}.portrait-label{position:absolute;bottom:42px;left:50%;transform:translateX(-50%);white-space:nowrap;display:flex;gap:8px;align-items:center;border:1px solid #ffffff20;border-radius:30px;background:#101b2ee6;padding:10px 14px;font-size:10px;color:#d6deed;backdrop-filter:blur(10px)}.formula{position:absolute;font-family:Georgia,serif;color:#7d96c34d;font-size:24px;transform:rotate(-12deg)}.f1{top:76px;left:7%}.f2{right:9%;top:85px;transform:rotate(13deg)}.orbit{position:absolute;border:1px solid #8ea8e118;border-radius:50%;width:1020px;height:380px;left:50%;bottom:45px;transform:translateX(-50%) rotate(-10deg);z-index:-1}.floating-note{position:absolute;z-index:4;bottom:148px;display:flex;gap:10px;align-items:center;padding:14px 17px;background:#162338e8;border:1px solid #ffffff15;border-radius:12px;box-shadow:0 10px 35px #0003;font-size:11px;transform:rotate(-5deg)}.floating-note>span{display:grid;place-items:center;width:30px;height:30px;border-radius:9px;background:#638cf51f;color:#9eb6ff;font-size:19px}.floating-note small{display:block;color:#8598b8;margin-top:5px;font-size:9px}.note-left{left:22%}.note-right{right:19%;bottom:120px;transform:rotate(5deg)}.scroll{position:absolute;bottom:30px;left:50%;transform:translateX(-50%);font-size:9px;letter-spacing:2px;color:#7f91ad;display:flex;align-items:center;gap:17px;white-space:nowrap}.scroll span{font-size:21px}.subject-bar{border-top:1px solid var(--line);border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-evenly;gap:18px;padding:25px 30px;background:#0f1828;color:#8293af;font-size:11px;letter-spacing:2px}.subject-bar i{font-style:normal;color:#627cae;font-size:20px}.section{max-width:1240px;margin:auto;padding:100px 45px}.section-heading{display:flex;justify-content:space-between;align-items:end;margin-bottom:42px;gap:35px}h2{font-size:40px;letter-spacing:-1.5px;line-height:1.22;margin:20px 0 0}.muted{color:#899ab4}.section-heading p,.practice-copy p{font-size:14px;color:var(--muted);line-height:1.85;margin:0 0 5px}.features{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.feature{border:1px solid var(--line);border-radius:16px;background:linear-gradient(140deg,#162239,#101a2b);padding:28px 26px;overflow:hidden;min-width:0}.feature-icon{font-size:24px;color:#8da7ff;background:#597bff16;border:1px solid #7799ff20;width:42px;height:42px;display:grid;place-items:center;border-radius:11px}.feature h3{font-size:18px;margin:25px 0 12px;letter-spacing:-.4px}.feature p{color:var(--muted);font-size:13px;line-height:1.8;margin:0;min-height:72px}.mini-task{background:#0c1525;border:1px solid #273650;border-radius:10px;margin-top:28px;padding:16px;font-size:10px;color:#8ea1be}.mini-task b{display:flex;justify-content:space-between;font-size:12px;color:#d2ddf0;margin:11px 0 19px}.segments{display:flex;gap:4px}.segments i{height:5px;background:#5477ed;border-radius:4px;flex:1}.segments i:nth-child(n+5){background:#253450}.mini-task small{display:block;margin-top:13px;font-size:9px}.book-visual{height:153px;position:relative;margin-top:26px;display:flex;justify-content:center;overflow:hidden}.book{width:125px;height:165px;transform:rotate(-10deg);background:#3755b9;border-left:7px solid #1c3686;border-radius:3px 8px 0 0;padding:17px;box-shadow:10px 10px 25px #0005}.book small{font-size:8px;letter-spacing:1px;color:#b9caff}.book strong{font-size:21px;display:block;margin:13px 0}.book>span{font:italic 39px Georgia;color:#9bb4ff}.book-tag{position:absolute;right:13px;bottom:15px;background:#1c2c49;border:1px solid #496194;border-radius:8px;padding:13px 20px;font-size:12px}.book-tag span{margin-left:15px;color:#8ba4ff}.chart{height:112px;display:flex;align-items:end;gap:11px;margin:31px 4px 12px;border-bottom:1px solid #34425b}.chart div{height:var(--h);background:linear-gradient(#7796fa,#314d9d);flex:1;border-radius:4px 4px 0 0}.chart-caption{color:#8fa1bd;font-size:10px}.practice-section{max-width:1240px;margin:10px auto 0;padding:65px 45px 90px;display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:80px}.practice-copy h2{font-size:43px;margin:22px 0}.practice-points{display:flex;flex-direction:column;gap:14px;color:#b6c6e0;font-size:12px;margin-top:30px}.practice-points span:first-letter{color:#8cafff}.hand-note{font:italic 24px Georgia;color:#93aaff;transform:rotate(-6deg);margin:40px 0 0 40px}.hand-note span{display:inline-block;font-size:47px;margin-left:30px;transform:rotate(25deg)}.quiz{border:1px solid #394b70;border-radius:20px;padding:27px 30px;background:linear-gradient(135deg,#192743,#111b2e);box-shadow:0 0 90px #334ab31a;min-width:0}.quiz-top{display:flex;justify-content:space-between;color:#94a8cf;font-size:9px;letter-spacing:1px}.quiz-top .tiny-dot{width:5px;height:5px;margin-right:5px}.quiz-progress{height:3px;background:#2c3a55;margin:20px 0 27px}.quiz-progress i{display:block;width:33.33%;height:100%;background:#7593ff;transition:width .3s}.quiz-topic{font-size:9px;letter-spacing:1.5px;color:#859cbe}.quiz h3{font-size:17px;font-weight:500;margin:14px 0}.equation{text-align:center;font:32px Georgia,serif;padding:16px 0 25px}.answers{display:grid;grid-template-columns:1fr 1fr;gap:10px}.answer{background:#101a2d;border:1px solid #35445f;border-radius:8px;padding:14px 10px;color:#c6d2e8;font-size:13px;transition:.15s}.answer:hover{border-color:#83a0ff}.answer[aria-pressed=true]{background:#304778;border-color:#8eabff}.answer.correct{border-color:#64cea6;background:#1b443e}.answer.wrong{border-color:#f29da5;background:#512e3d}.feedback{min-height:40px;font-size:12px;line-height:1.5;color:#aebed8;margin:20px 0 14px}.quiz-bottom{display:flex;align-items:center;justify-content:space-between;gap:15px}.hint-button{background:none;border:0;color:#a1b5d8;padding:10px 0;font-size:11px}.demo-note{display:block;margin-top:20px;font-size:9px;color:#8194b3}.teacher-message{position:relative;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:45px 65px;display:flex;flex-direction:column;align-items:center;text-align:center}.quote-mark{font:90px Georgia;color:#708df6;height:60px}blockquote{font-size:25px;line-height:1.6;letter-spacing:-.4px;max-width:780px;margin:15px 0 30px;color:#d4dff1}.team-signature{display:flex;align-items:center;gap:17px;text-align:left}.team-signature b{font-size:13px}.team-signature span{display:block;font-size:11px;color:#8d9eb9;margin-top:6px}.avatars{display:flex}.avatars img{width:44px;height:44px;border-radius:50%;object-fit:cover;object-position:top;background:#2b3d63;border:3px solid #0b1220}.avatars img+img{margin-left:-9px}.teachers-section{padding-top:50px;padding-bottom:40px}.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:50px;margin-top:45px}.steps article{border-top:1px solid #34415a;padding-top:25px}.steps article>span{font-size:13px;color:#7e9aff}.steps h3{font-size:18px;margin:20px 0 12px}.steps p{font-size:13px;color:#9aa9bf;line-height:1.8;margin:0}.how{padding-top:65px;padding-bottom:80px}.faq{display:grid;grid-template-columns:1fr 1.2fr;gap:60px;padding-top:35px;padding-bottom:100px}.faq h2{font-size:32px}details{border-bottom:1px solid var(--line)}summary{padding:23px 0;cursor:pointer;font-size:14px;list-style:none;display:flex;justify-content:space-between;gap:15px}summary::-webkit-details-marker{display:none}summary:after{content:'+';font-size:20px;color:#8ca5db}details[open] summary:after{content:'−'}details p{font-size:13px;color:#a6b5cb;line-height:1.8;margin:0 0 23px}.final-cta{position:relative;text-align:center;padding:75px 24px 80px;border-top:1px solid #24324a;border-bottom:1px solid #24324a;background:radial-gradient(ellipse at 50% 100%,#25367455,transparent 70%)}.final-cta h2{font-size:42px;margin:24px 0 30px}.final-cta p{font-size:11px;color:#8497b4;margin-top:20px}footer{max-width:1340px;margin:auto;padding:35px 45px;display:flex;align-items:center;justify-content:space-between}footer p,footer>span{font-size:11px;color:#8191aa}footer .logo b{font-size:18px}footer .logo-mark{width:32px;height:32px;font-size:11px}.skip{position:fixed;top:-80px;left:20px;z-index:100;background:#244ec1;padding:15px}.skip:focus{top:10px}dialog{background:#142139;color:#f8fafc;border:1px solid #41557b;border-radius:20px;padding:38px;max-width:480px;width:calc(100% - 32px);box-shadow:0 30px 120px #0009}dialog::backdrop{background:#040913c9;backdrop-filter:blur(7px)}dialog h2{font-size:32px}dialog>p{font-size:14px;color:#a9bad4;line-height:1.7}.close{position:absolute;top:12px;right:15px;border:0;background:none;font-size:28px;color:#a7b9d6;padding:5px 10px}.login-preview{padding:20px;background:#0d1729;border:1px solid #304264;border-radius:12px;margin:25px 0}.login-preview>span{font-size:10px;letter-spacing:1.4px;color:#9ab2ff}.login-preview p{font-size:13px;color:#adbed8;line-height:1.7}.login-preview p:last-child{margin-bottom:0}dialog>.button{width:100%}@media(min-width:1500px){.teacher-portrait.left{left:5%}.teacher-portrait.right{right:5%}}@media(max-width:1100px){header{padding:0 28px}.hero{min-height:740px}.hero-copy{padding-top:55px}h1{font-size:55px}.teacher-portrait{width:29%;height:360px;bottom:50px}.hero-copy p{font-size:14px}.note-left{left:20%;bottom:113px}.note-right{right:16%;bottom:83px}.portrait-label{font-size:8px;padding:8px}.hero-actions{gap:16px}.micro{font-size:9px}.section,.practice-section{padding-left:28px;padding-right:28px}.practice-section{gap:40px}.feature{padding:24px 20px}.features{gap:13px}.section-heading p{font-size:12px}.subject-bar{font-size:9px}.practice-copy h2{font-size:37px}.quiz{padding:24px}.f1{left:4%;font-size:19px}.f2{right:4%;font-size:21px}}@media(max-width:760px){header{height:76px;padding:0 20px}nav{display:none}.logo b{font-size:20px}.logo-mark{width:35px;height:35px}.button.small{padding:11px 16px;font-size:12px}.hero{min-height:870px}.hero-copy{padding:42px 18px 0}.hero .eyebrow{font-size:9px;letter-spacing:1.5px}h1{font-size:clamp(39px,7.9vw,57px);letter-spacing:-1.8px;margin:23px 0}.hero-copy p{font-size:14px;line-height:1.75;margin:27px 0 23px}.hero-actions{flex-direction:column;gap:20px}.micro{font-size:9px;margin-top:18px}.teacher-portrait{width:48%;height:340px;bottom:48px;max-width:none}.teacher-portrait.left{left:0}.teacher-portrait.right{right:0}.portrait-label{bottom:24px;font-size:8px;padding:8px 9px;gap:5px}.floating-note{display:none}.f1{top:478px;font-size:20px;left:9%}.f2{top:460px;right:9%;font-size:20px}.orbit{width:750px;height:270px;bottom:80px}.scroll{font-size:8px;bottom:15px;letter-spacing:1.3px}.subject-bar{overflow:hidden;justify-content:center;white-space:nowrap;gap:19px;padding:21px 15px;font-size:8px;letter-spacing:1px}.subject-bar span:nth-last-child(-n+3),.subject-bar i:nth-last-child(-n+4){display:none}.section{padding:64px 22px}.section-heading{display:block;margin-bottom:30px}.section-heading p{margin-top:22px;font-size:13px}h2{font-size:32px;letter-spacing:-1px}.features{grid-template-columns:1fr;gap:16px}.feature{padding:25px;position:relative}.feature p{min-height:0;max-width:380px}.mini-task{margin-top:22px}.feature h3{margin-top:20px}.book-visual{height:130px}.chart{height:100px}.practice-section{grid-template-columns:1fr;padding:15px 22px 65px;gap:30px}.practice-copy h2{font-size:34px}.practice-copy p{font-size:13px}.practice-points{flex-direction:row;flex-wrap:wrap;font-size:10px;gap:15px;margin-top:22px}.hand-note{display:none}.quiz{padding:23px 19px}.equation{font-size:29px}.quiz-bottom .button{padding:14px 19px;gap:25px}.teachers-section{padding-top:10px;padding-bottom:40px}.teacher-message{padding:25px 0 35px}blockquote{font-size:20px}.team-signature span{font-size:9px;line-height:1.6;max-width:205px}.steps{grid-template-columns:1fr;gap:30px;margin-top:35px}.steps article{padding-top:20px}.steps h3{margin-top:14px}.how{padding-top:20px;padding-bottom:55px}.faq{display:block;padding-top:10px}.faq>div:first-child{margin-bottom:25px}.faq h2{font-size:30px}summary{font-size:13px}.final-cta{padding:60px 20px}.final-cta h2{font-size:31px}footer{padding:30px 22px;flex-wrap:wrap;gap:22px}footer p{display:none}footer>span{font-size:10px}.desktop{display:none}}@media(max-width:380px){.hero{min-height:835px}.teacher-portrait{height:300px}.portrait-label{font-size:7px}h1{font-size:38px}.micro{font-size:8px}.hero-copy p{font-size:13px}.quiz-top{font-size:8px}.answer{font-size:12px}.team-signature{gap:10px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}
@media(max-width:760px){.hero{min-height:770px}.f1{top:455px}.f2{top:452px}.teacher-portrait{bottom:38px}.portrait-label{bottom:22px}}@media(max-width:380px){.hero{min-height:735px}.f1,.f2{top:440px}}
@media(min-width:1101px){.note-right{bottom:180px;right:22%}.note-left{bottom:175px}}
