/* Landing-only design. Learning and quiz layouts keep their own styles. */
.top-bar h1{display:flex;align-items:center;gap:10px}.brand-icon{display:block;flex:none;width:36px;height:36px}
body:has(#home-page:not(.hidden) #topic-panel:not(.hidden)){background:#f8faf7}
body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar{border-radius:0;border-bottom:1px solid #e2e8e4;height:80px;min-height:72px;transform:none;animation:none;padding:0 max(24px,calc((100vw - 1200px)/2))}
body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar h1{font-size:25px;letter-spacing:-1px;color:#183648}
body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar p{color:#657d80;font-size:13px}
body:has(#home-page:not(.hidden) #topic-panel:not(.hidden)) .device-save-note,body:has(#home-page:not(.hidden) #topic-panel:not(.hidden)) .math-atmosphere{display:none}
#home-page:has(#topic-panel:not(.hidden)){background:#f8faf7;padding:125px 32px 0;color:#17364a;min-height:100dvh;animation:none}
#topic-panel{max-width:1200px;width:100%}#topic-panel:not(.hidden){animation:none}
#topic-panel .home-hero{grid-template-columns:minmax(0,1.02fr) minmax(0,1fr);gap:58px;min-height:0;padding:14px 0 58px;align-items:center}
#topic-panel .hero-copy{color:#17364a}
#topic-panel .eyebrow{font-size:10px;letter-spacing:1.7px;color:#507170;line-height:1.6;font-weight:750}
.landing-dot{display:inline-block;width:7px;height:7px;border-radius:50%;background:#258f6c;margin-right:8px}
#topic-panel .hero-copy h2{font-size:clamp(48px,5.25vw,72px);letter-spacing:-3.5px;line-height:1.06;margin:24px 0;max-width:none;font-weight:750}
#topic-panel .hero-copy h2 em{font-family:inherit;font-style:normal;font-weight:650;color:#1769e0;letter-spacing:inherit}
#topic-panel .hero-intro{font-size:17px;line-height:1.8;color:#556d79;max-width:480px}
.landing-tiers{display:flex;flex-wrap:wrap;gap:9px 14px;margin:24px 0;color:#4d696f;font-size:12px}.landing-tiers span+span::before{content:'·';margin-right:14px;color:#93a9aa}
#topic-panel .topic-button{display:inline-flex;align-items:center;justify-content:center;min-width:230px;min-height:56px;margin:2px 0 0;background:#1769e0;color:white;border-radius:10px;font-size:15px;box-shadow:0 6px 15px #1769e020}
#topic-panel .topic-button:hover{background:#125dc9;transform:translateY(-2px);box-shadow:0 8px 19px #1769e02b}
.landing-entry-note{font-size:11px;line-height:1.6;color:#70838b;margin:12px 0 0}
.math-notebook{min-width:0;border:1px solid #dbe5de;border-radius:16px;background:#fff;box-shadow:0 18px 55px #213e4e0b;overflow:hidden;transform:rotate(1deg)}
.notebook-heading{display:flex;justify-content:space-between;gap:10px;align-items:center;padding:18px 23px;border-bottom:1px solid #e6ece6;color:#5d777d;font-size:9px;font-weight:700;letter-spacing:1px}.notebook-heading i{display:inline-block;width:6px;height:6px;background:#48a284;border-radius:50%;margin-right:6px}
.notebook-graph{position:relative;padding:25px 24px 8px;background:#f8faf7}.graph-caption{display:block;font-family:Georgia,serif;font-style:italic;font-size:14px;color:#6a807e;margin-bottom:18px}.notebook-graph svg{display:block;width:100%;height:auto;overflow:visible}
.landing-curve{stroke-dasharray:600;stroke-dashoffset:0;animation:draw-math-curve 1.6s ease-out both}@keyframes draw-math-curve{from{stroke-dashoffset:600}to{stroke-dashoffset:0}}
.notebook-sticker{position:absolute;right:20px;bottom:19px;background:#eaf2c7;color:#445330;padding:13px 36px 13px 15px;border:1px solid #dce7b5;transform:rotate(-7deg);box-shadow:0 5px 10px #3648310c;font:italic 13px/1.6 Georgia,serif}.notebook-sticker strong{font-weight:400}.notebook-sticker>span{position:absolute;right:12px;top:14px;font-size:23px}
.notebook-example{display:grid;grid-template-columns:1fr auto;gap:14px;align-items:center;padding:22px 24px;border-top:1px solid #e3eae2}.example-label{font-size:8px;letter-spacing:1.4px;color:#628087;font-weight:700}.example-equation{font:italic 30px/1.2 Georgia,serif;margin:10px 0 0;color:#183648}.notebook-example button{background:#fff;border:1px solid #d6e1df;border-radius:8px;color:#355d66;font:600 11px/1.5 system-ui;padding:11px 13px;cursor:pointer;min-height:44px}.notebook-example button:hover{background:#f0f6f1}.notebook-example button span{margin-left:8px}
#landing-example-solution{grid-column:1/-1;border-top:1px dashed #d9e5de;padding-top:5px}#landing-example-solution[hidden]{display:none}#landing-example-solution p{display:flex;align-items:center;gap:10px;font-size:12px;line-height:1.6;color:#526d75}#landing-example-solution p>span{font-size:10px;color:#718a8c}#landing-example-solution strong{margin-left:auto;font:italic 19px Georgia,serif;white-space:nowrap;color:#1769e0}
.landing-method{display:grid;grid-template-columns:1.2fr 1fr 1fr 1fr;gap:30px;padding:32px 0 40px;border-top:1px solid #dce5de;border-bottom:1px solid #dce5de}.method-intro h3{font-size:22px;letter-spacing:-.7px;line-height:1.3;margin:13px 0 0}.landing-method article{padding-left:24px;border-left:1px solid #dce5de}.method-number{display:flex;justify-content:space-between;font-size:12px;color:#70878a}.method-number i{font-style:normal;color:#288266}.landing-method h4{font-size:14px;line-height:1.4;margin:18px 0 9px}.landing-method p{font-size:12px;line-height:1.8;color:#617781;margin:0}
.landing-creator{display:flex;align-items:center;gap:22px;padding:30px 0}.creator-mark{font:42px Georgia,serif;color:#27886c;flex:0 0 50px}.landing-creator h3{font-size:14px;margin:0 0 8px;line-height:1.5}.landing-creator .creator-note{font-size:12px;line-height:1.8;color:#647982;max-width:710px;margin:0}.creator-signature{font:italic 17px/1.5 Georgia,serif;color:#5b7b74;margin-left:auto;white-space:nowrap;transform:rotate(-5deg)}
.landing-footer{border-top:1px solid #dce5de;padding:22px 0 26px;display:flex;align-items:center;justify-content:space-between;gap:14px;color:#698184;font-size:10px}.landing-footer>span:first-child{font-size:13px;font-weight:750;color:#315867}.landing-footer p{margin:0}
#topic-panel button:focus-visible,#topic-panel a:focus-visible{outline:3px solid #79aaf1;outline-offset:4px}
@media(min-width:1500px){#topic-panel .home-hero{padding:35px 0 75px}}
@media(max-width:950px){#topic-panel .home-hero{gap:28px}#topic-panel .hero-copy h2{font-size:53px;letter-spacing:-2.5px}#topic-panel .hero-intro{font-size:15px}.notebook-example{padding:18px}.notebook-heading{padding:16px;font-size:8px}.landing-method{gap:18px}.landing-method article{padding-left:18px}.creator-signature{display:none}}
@media(max-width:700px){body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar{padding:0 20px;height:72px}body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar p{display:none}#home-page:has(#topic-panel:not(.hidden)){padding:102px 22px 0}#topic-panel .home-hero{grid-template-columns:1fr;gap:36px;padding:0 0 35px}#topic-panel .hero-copy h2{font-size:56px;letter-spacing:-2.8px;margin:20px 0}#topic-panel .hero-intro{font-size:15px;max-width:500px}.math-notebook{transform:none;max-width:530px;width:100%;justify-self:center}.landing-method{grid-template-columns:1fr;gap:23px;padding:27px 0}.method-intro h3 br{display:none}.landing-method article{padding:0 0 0 16px;position:relative}.method-number{position:absolute;left:16px;top:0;width:28px}.method-number i{display:none}.landing-method h4{margin:0 0 7px 39px}.landing-method article p{margin-left:39px}.landing-creator{align-items:flex-start;gap:12px;padding:26px 0}.creator-mark{flex-basis:30px;font-size:32px}.landing-footer{flex-wrap:wrap;gap:10px}.landing-footer>span:last-child{width:100%;font-size:9px}}
@media(max-width:370px){#topic-panel .hero-copy h2{font-size:47px}#topic-panel .eyebrow{font-size:8px;letter-spacing:1.2px}.notebook-heading{font-size:7px;padding:14px 12px}.notebook-graph{padding:20px 12px 8px}.notebook-example{padding:17px 12px;gap:8px}.notebook-example button{font-size:10px;padding:10px 8px}.example-equation{font-size:27px}.notebook-sticker{font-size:11px;right:10px;bottom:12px}#landing-example-solution p{font-size:10px;gap:5px}.brand-icon{width:30px;height:30px}}
@media(prefers-reduced-motion:reduce){.landing-curve{animation:none}#topic-panel .topic-button{transition:none;transform:none}}
/* Shared brand shell: stable between the public page and learning workspace. */
.top-bar,body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar{height:80px;min-height:80px;border-radius:0;border-bottom:1px solid #e2e8e4;transform:none;animation:none;padding:0 max(24px,calc((100vw - 1200px)/2))}
.top-bar h1,body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar h1{font-size:25px;letter-spacing:-1px;color:#183648}
.top-bar p,body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar p{font-size:13px;color:#657d80}
.top-bar h1:focus-visible{outline:3px solid #8bb7fa;outline-offset:6px;border-radius:4px}
body.workspace-mode{background:#f8faf7}.workspace-mode .ws-card{border-color:#dce5de;box-shadow:0 4px 16px #213e4e03}.workspace-mode .ws-header h2{letter-spacing:-.8px;color:#183648}.workspace-mode .eyebrow{color:#507170;font-size:10px;letter-spacing:1.5px;font-weight:750}.ws-nav{border-color:#e2e8e4}.ws-nav button[aria-current=page]{background:#eaf2ee;color:#24694f}
.db-focus{display:grid;grid-template-columns:minmax(0,1fr) 230px;gap:36px;padding:30px}.db-focus h3{font-size:clamp(26px,3vw,36px);letter-spacing:-1px;line-height:1.2;max-width:650px}.db-focus .db-course{font-size:13px;color:#55736e}.db-focus .ws-actions{margin-top:24px}.db-focus>div>p:not(.eyebrow){max-width:590px}.db-note{background-color:#f5f8f1;background-image:linear-gradient(#dbe5dc55 1px,transparent 1px),linear-gradient(90deg,#dbe5dc55 1px,transparent 1px);background-size:22px 22px;border:1px solid #e0e8dc;border-radius:12px;padding:22px;display:flex;flex-direction:column;align-items:flex-start;justify-content:center;color:#48655e}.db-note-label{font-size:10px;letter-spacing:1px;font-weight:700}.db-note strong{font-size:46px;line-height:1.25;color:#183648}.db-note>span:not(.db-note-label){font-size:13px}.db-note p{font-size:13px}.db-handwriting{font-family:Georgia,serif;font-style:italic}
.db-section-heading{display:flex;align-items:baseline;justify-content:space-between;gap:12px;flex-wrap:wrap;margin:30px 0 14px}.db-section-heading h3{font-size:20px;margin:0}.db-section-heading span{font-size:13px;color:#647970}.db-secondary .ws-card{padding:22px}.db-secondary h3{font-size:20px}.db-secondary .ws-card>p:not(.eyebrow){font-size:14px}.db-help{margin-top:28px;border-top:1px solid #dce5de;padding:18px 0;color:#556d79;font-size:13px;line-height:1.7}.db-help summary{cursor:pointer;color:#355b51}.db-help h3{font-size:16px;margin-bottom:4px;color:#183648}.db-help p{margin-top:0;max-width:760px}.db-help a{color:#1769e0}.landing-help{flex-basis:100%;width:100%}.landing-footer{flex-wrap:wrap}.landing-footer .db-help{margin-top:0;text-align:left}.landing-footer .db-help p{font-size:13px}
@media(max-width:760px){.db-focus{grid-template-columns:1fr;padding:20px;gap:22px}.db-note{padding:16px;display:grid;grid-template-columns:1fr 1fr;gap:4px 16px}.db-note strong{grid-column:1;grid-row:2;font-size:34px}.db-note p{grid-column:2;grid-row:1/4;margin:0}.db-note .db-handwriting{grid-column:1/-1;margin-top:6px}.db-secondary .ws-card{padding:20px}.top-bar,body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar{height:72px;min-height:72px;padding:0 16px;gap:10px}.top-bar h1,body:has(#home-page:not(.hidden) #topic-panel:not(.hidden))>.top-bar h1{font-size:22px}.top-bar p{display:none}.brand-icon{width:30px;height:30px}}

.top-bar.bar-enter{animation:none}
/* Distinct registration entry points; guest practice remains available. */
.signup-cta{border:1px solid #1769e0;border-radius:999px;background:#1769e0;color:#fff;padding:12px 20px;font:inherit;font-weight:650;cursor:pointer;white-space:nowrap}
.signup-cta:hover{background:#1258bf}
.signup-cta:focus-visible{outline:3px solid #17364c;outline-offset:4px}
.landing-actions{display:flex;flex-wrap:wrap;align-items:center;gap:12px}
.landing-actions .workspace-start{background:transparent;color:#17364c;border:1px solid #cbd9e2;box-shadow:none}
.header-signup{flex-shrink:0}
@media(max-width:600px){.top-bar{gap:8px;padding-left:14px;padding-right:14px}.top-bar p{display:none}.top-bar h1{font-size:18px}.top-bar .brand-icon{width:26px;height:26px}.header-signup{padding:10px 11px;font-size:12px}.top-bar .account-button{padding:10px;font-size:12px}}
body #topic-panel .landing-actions .workspace-start{background:transparent;color:#17364c;border:1px solid #cbd9e2;box-shadow:none}
.top-bar .brand-wordmark{display:flex;flex-direction:column;line-height:1.05}.top-bar .brand-wordmark small{font-size:10px;font-weight:550;letter-spacing:.2px;color:#658078;margin-top:4px;white-space:nowrap}
@media(max-width:600px){.top-bar .brand-wordmark small{font-size:9px;margin-top:3px}}