
:root{--paper:#faf5e9;--ink:#243c38;--orange:#e9683b;--light:#fffdf7;--blue:#b8dce4;--yellow:#f4cb62;--line:#d7d4c6;--muted:#68776d;--serif:"Iowan Old Style","Palatino Linotype","Songti TC",serif;--sans:"Avenir Next","Trebuchet MS","PingFang TC",sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:25px}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.7 var(--sans)}button,input,textarea{font:inherit}button,a,input,textarea{-webkit-tap-highlight-color:transparent}button{color:inherit;cursor:pointer;touch-action:manipulation}a{color:inherit;text-decoration:none}button{border:0;background:none}button:disabled{cursor:default;opacity:.5}h1,h2,h3,p{margin:0}h1,h2,h3{line-height:1.25}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #df683a;outline-offset:4px}a:hover{text-decoration:underline}button:hover:not(:disabled){filter:brightness(.97)}[hidden]{display:none!important}.skip{position:fixed;top:-100px;left:20px;z-index:20;background:var(--ink);color:white;padding:12px}.skip:focus{top:10px}.shell{max-width:1240px;margin:auto;padding:0 42px}.mast{display:flex;align-items:center;justify-content:space-between;gap:18px;padding:23px 0;border-bottom:1px solid var(--line)}.brand{font:34px/1 var(--serif);display:flex;align-items:center;gap:13px}.brand .brand-icon{width:36px;height:36px;background:var(--orange);color:var(--paper);border-radius:50%;display:grid;place-items:center;font:25px var(--sans);transform:rotate(-12deg)}.brand small{display:block;font:10px/1.8 var(--sans);letter-spacing:.15em;margin-top:7px}.mast-right{display:flex;align-items:center;gap:25px}.quiet{font-size:12px;color:var(--muted)}.languages{display:flex;border:1px solid var(--line);border-radius:30px;padding:3px;gap:3px}.languages button{font-size:12px;border-radius:25px;min-height:37px;min-width:42px;padding:6px 10px}.languages [aria-pressed=true]{background:var(--ink);color:var(--paper)}.issue{font-size:10px;letter-spacing:.18em;color:var(--muted);display:flex;justify-content:space-between;padding:19px 0}.hero{display:grid;grid-template-columns:1.04fr 1fr;align-items:center;gap:42px;padding:29px 0 44px}.eyebrow{font-size:11px;letter-spacing:.12em;text-transform:uppercase;font-weight:600}.hero h1{font-family:var(--serif);font-weight:600;font-size:clamp(42px,4.8vw,64px);line-height:1.12;margin:17px 0 23px;letter-spacing:-.025em}.hero h1 em{color:var(--orange);font-style:normal;display:inline-block;position:relative}.hero h1 em:after{content:"";height:5px;background:var(--yellow);position:absolute;left:0;right:0;bottom:-8px;transform:rotate(-2deg)}.lead{color:var(--muted);font-size:15px;max-width:420px}.hero-actions{display:flex;gap:18px;align-items:center;flex-wrap:wrap;margin:27px 0 17px}.primary,.secondary{display:inline-flex;align-items:center;justify-content:center;gap:12px;padding:13px 23px;border-radius:7px;font-size:14px;font-weight:600;min-height:48px}.primary{background:var(--ink);color:var(--light);border:1px solid var(--ink)}.secondary{border:1px solid var(--ink);background:transparent}.primary:hover,.secondary:hover{text-decoration:none}.hero small{font-size:11px;color:var(--muted)}.hero-art{position:relative;margin:0;padding:12px 12px 0;background:#fffdf8;border:1px solid var(--ink);border-radius:100px 8px 8px 8px;box-shadow:7px 7px 0 #e3e6d7;transform:rotate(1deg)}.hero-art img{display:block;width:100%;height:auto;aspect-ratio:3/2;object-fit:cover;border-radius:85px 3px 0 0}.hero-art figcaption{border-top:1px solid var(--line);padding:12px 5px;font-size:11px;display:flex;justify-content:space-between;gap:10px}.sticker{position:absolute;right:-14px;top:-20px;width:78px;height:78px;border-radius:50%;background:var(--yellow);border:1px solid var(--ink);display:grid;place-items:center;font:italic 24px var(--serif);transform:rotate(9deg)}.topic-strip{border-block:1px solid var(--line);display:grid;grid-template-columns:repeat(3,1fr);padding:19px 0;gap:22px}.topic-strip>div{display:flex;gap:13px;align-items:center;font-size:12px}.topic-strip b{font:26px var(--serif);color:var(--orange)}.topic-strip strong{display:block;font-size:12px}.topic-strip span{color:var(--muted);font-size:11px}.section{padding:58px 0 0;scroll-margin-top:25px}.section-head{display:flex;justify-content:space-between;gap:25px;align-items:flex-end;margin-bottom:25px}.section-head h2{font:600 30px/1.25 var(--serif);margin-top:8px}.section-head>p{font-size:12px;color:var(--muted);max-width:330px}.lesson-nav{display:flex;flex-wrap:wrap;gap:8px;margin:26px 0 0}.lesson-nav a{font-size:12px;padding:7px 13px;background:#efeddf;border:1px solid transparent;border-radius:22px}.lesson-nav a:hover{border-color:var(--ink);text-decoration:none}.story-board{border:1px solid var(--ink);border-radius:12px;overflow:hidden;background:var(--light)}.story-top{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:16px 26px;background:#f1e9d9;border-bottom:1px solid var(--ink);font-size:12px}.scene-dots{display:flex;gap:7px}.scene-dots button{width:32px;height:32px;border-radius:50%;border:1px solid var(--ink);font-size:11px}.scene-dots [aria-current=true]{background:var(--ink);color:var(--light)}.story-scene{display:grid;grid-template-columns:1fr 1fr;min-height:385px}.scene-art{padding:30px;background-image:radial-gradient(#dcd9c7 .9px,transparent .9px);background-size:9px 9px;display:flex;flex-direction:column;justify-content:center;gap:18px;border-right:1px solid var(--ink)}.scene-copy{padding:34px;display:flex;flex-direction:column;justify-content:center}.scene-copy h3{font:600 27px var(--serif);margin-bottom:20px}.dialogue{display:flex;gap:12px;margin:0 0 15px;align-items:flex-start}.avatar{width:42px;height:42px;flex:0 0 42px}.bubble{padding:13px 15px;border:1px solid var(--ink);border-radius:4px 13px 13px;font-size:14px;background:white}.bubble small{display:block;font-size:10px;font-weight:700;color:var(--muted);margin-bottom:3px}.reveal{margin-top:7px;border-left:3px solid var(--orange);padding-left:14px;font-size:13px}.scene-controls{display:flex;justify-content:space-between;padding:18px 26px;border-top:1px solid var(--line);gap:12px;align-items:center}.scene-controls span{font-size:11px;color:var(--muted)}.text-button{font-size:13px;text-decoration:underline;text-underline-offset:4px;min-height:42px}.recipe-label{display:flex;justify-content:space-between;font-size:12px;gap:15px;margin-bottom:10px}.packets{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;align-items:center}.packet{width:49px;height:60px;border:1.5px solid var(--ink);border-radius:4px 4px 9px 9px;background:var(--blue);display:flex;align-items:center;justify-content:center;flex-direction:column;box-shadow:2px 2px 0 #243c3812;font:10px var(--sans)}.packet.syrup{background:#f49c59}.packet b{font-size:13px}.packet .drop{font-size:17px;line-height:1.5}.packet-label{font-size:10px;text-align:center;margin-top:9px;color:var(--muted)}.recipe-card{border:1px solid var(--ink);background:var(--paper);padding:17px;border-radius:8px}.fraction-note{text-align:center;font:32px var(--serif);padding:15px 5px 0}.fraction-note b{color:var(--orange)}.stamp{font-size:13px;text-align:center;background:var(--yellow);align-self:center;padding:6px 18px;border:1px solid var(--ink);transform:rotate(-3deg)}.lab{display:grid;grid-template-columns:1fr 1.1fr;border:1px solid var(--ink);border-radius:12px;overflow:hidden}.lab-controls{padding:29px;background:var(--ink);color:var(--paper)}.lab-controls h3{font:27px var(--serif);margin-bottom:12px}.lab-controls>p{font-size:12px;opacity:.8}.control{margin-top:27px}.control label{display:flex;align-items:center;justify-content:space-between;gap:12px;font-size:13px}.control output{font:22px var(--serif);min-width:70px;text-align:right}.control input{width:100%;accent-color:#f4ac65;display:block;margin:15px 0;height:27px;cursor:pointer}.presets{display:flex;gap:9px;flex-wrap:wrap;margin-top:21px}.presets button{font-size:11px;background:#ffffff16;border:1px solid #ffffff66;border-radius:6px;padding:8px 12px;min-height:42px}.lab-display{padding:29px;background:var(--light)}.lab-display>p{font-size:12px;color:var(--muted)}.mass-bar{display:flex;min-height:78px;border:1px solid var(--ink);border-radius:7px;overflow:hidden;margin:19px 0 13px;background:var(--blue)}.mass-bar .mass-syrup{background:#f49c59;border-right:1px solid var(--ink);min-width:2px;transition:width .2s}.mass-legend{display:flex;justify-content:space-between;font-size:11px;gap:20px;margin:6px 0 21px}.mass-legend span:before{content:"";display:inline-block;width:10px;height:10px;background:#f49c59;margin-right:7px}.mass-legend span:last-child:before{background:var(--blue)}.formula{font:30px/1.4 var(--serif);text-align:center;padding:15px 0}.formula small{font:12px var(--sans);display:block;color:var(--muted);margin-bottom:6px}.mix-verdict{font-size:13px;padding:14px 16px;background:#eaf0dd;border-radius:7px;min-height:72px;margin-top:15px}.extension{font-size:13px;margin-top:19px;border-top:1px solid var(--line);padding-top:16px}.extension summary{cursor:pointer}.extension p{margin-top:12px}.model-note{font-size:11px;color:var(--muted);margin-top:13px}.challenge{display:grid;grid-template-columns:240px 1fr;gap:32px}.quiz-aside{background:#eeeadd;border-radius:10px;padding:24px;align-self:start}.score{font:53px/1.2 var(--serif);margin:12px 0}.score small{font-size:22px;color:var(--muted)}.quiz-aside p{font-size:12px;color:var(--muted)}.quiz-dots{display:flex;gap:6px;margin:20px 0 12px}.quiz-dots i{height:9px;background:#d6d5c6;flex:1;border-radius:3px}.quiz-dots .done{background:var(--ink)}.question{padding:25px 0;border-top:1px solid var(--line)}.question:first-child{padding-top:0;border:0}.question h3{font-size:17px;line-height:1.6;margin:7px 0 16px;font-weight:500}.question-kicker{font-size:10px;letter-spacing:.12em;color:var(--muted)}.choices{display:grid;grid-template-columns:repeat(3,1fr);gap:9px}.choice{font-size:14px;text-align:left;padding:14px 13px;min-height:60px;border:1px solid var(--line);border-radius:7px;background:var(--light)}.choice [aria-hidden]{font-size:10px;display:block;color:var(--muted)}.choice[aria-pressed=true]{border:2px solid var(--ink);padding:13px 12px;background:#edf0df}.choice:disabled{opacity:1}.question-actions{display:flex;gap:15px;margin-top:13px;align-items:center}.question-actions .primary{min-height:39px;padding:9px 15px;font-size:12px}.hint{margin:12px 0;font-size:12px;color:var(--muted)}.feedback{padding:13px 16px;border-radius:6px;font-size:13px;margin-top:14px;background:#f9e6cd}.feedback.success{background:#e7edd9}.feedback strong{display:block;margin-bottom:3px}.notebook{display:grid;grid-template-columns:1fr 1fr;gap:35px;background:var(--yellow);border:1px solid var(--ink);padding:30px;border-radius:12px;box-shadow:5px 5px 0 #e7dcc0}.notebook h3{font:29px var(--serif);margin-bottom:12px}.takeaway{font-size:14px;line-height:1.85;margin:12px 0}.takeaway li{margin:6px 0}.notebook label{display:block;font-size:12px;margin-bottom:9px}.notebook textarea{width:100%;min-height:134px;resize:vertical;background:#fffdf6;border:1px solid var(--ink);border-radius:6px;padding:14px;font-size:14px;line-height:1.65}.save-status{font-size:10px;min-height:19px;margin-top:5px}.notebook .text-button{font-size:11px}.route-list{margin-top:10px}.route-row{display:grid;grid-template-columns:45px 1fr 1.2fr 110px;gap:20px;padding:19px 0;border-bottom:1px solid var(--line);align-items:center}.route-row .num{font:28px var(--serif);color:var(--muted)}.route-row h3{font-size:16px;margin-top:5px;line-height:1.5}.route-row .subject{font-size:10px;color:var(--orange)}.route-row p{font-size:12px;color:var(--muted)}.status{justify-self:end;font-size:10px;border:1px solid var(--line);padding:4px 12px;border-radius:25px}.status.live{background:var(--ink);color:var(--paper)}.parents{margin:37px 0 50px;font-size:12px;color:var(--muted);border:1px solid var(--line);padding:18px 22px;border-radius:8px}.parents summary{cursor:pointer;color:var(--ink)}.parents p{margin:13px 0}.parents a{text-decoration:underline}.parents li{margin:8px 0}.footer{border-top:1px solid var(--line);padding:25px 0 30px;display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;font-size:11px;color:var(--muted)}.storage-warning{padding:12px 18px;border:1px solid #d89860;background:#fff0d8;font-size:12px;margin:20px 0}.completion{margin-top:15px;font-size:12px;padding:12px;border:1px dashed var(--ink);background:#f6f0da}.art-caption{font-size:10px;color:var(--muted)}
.comic-frame{position:relative;aspect-ratio:3/2;border:1.5px solid var(--ink);border-radius:8px;overflow:hidden;background:#f4e8d0;isolation:isolate}.comic-frame img{position:absolute;width:200%;height:200%;max-width:none;object-fit:fill}.comic-number{position:absolute;left:8px;top:8px;font:italic 17px var(--serif);background:var(--paper);border:1px solid var(--ink);border-radius:50%;width:31px;height:31px;display:grid;place-items:center;box-shadow:2px 2px 0 #243c3822}.comic-frame+.recipe-card{margin-top:0}.scene-art{justify-content:flex-start;gap:15px}.bubble{box-shadow:3px 3px 0 #243c3810}.scene-copy .dialogue:nth-child(2) .bubble{transform:rotate(-1deg)}.scene-copy .dialogue:nth-child(3) .bubble{transform:rotate(.6deg)}
@media(min-width:1000px){.hero{min-height:420px}.scene-art{padding-inline:45px}}
@media(max-width:850px){.shell{padding:0 24px}.hero{gap:28px}.hero h1{font-size:45px}.hero-art{border-radius:65px 8px 8px 8px}.hero-art img{border-radius:53px 3px 0 0}.scene-copy{padding:25px}.scene-art{padding:22px}.challenge{grid-template-columns:180px 1fr;gap:24px}.route-row{grid-template-columns:33px 1fr 1fr 88px;gap:12px}}
@media(max-width:640px){body{font-size:15px}.shell{padding:0 18px}.mast{padding:19px 0;gap:10px}.brand{font-size:28px;gap:8px}.brand .brand-icon{width:30px;height:30px;font-size:22px}.brand small{font-size:8px;letter-spacing:.1em}.mast-right{gap:8px}.mast-right>.quiet{display:none}.languages button{font-size:11px;min-width:35px;padding:6px 8px;min-height:34px}.issue{font-size:8px;letter-spacing:.1em;padding:16px 0}.hero{grid-template-columns:1fr;padding:15px 0 27px;gap:30px}.hero h1{font-size:47px;max-width:430px;margin:13px 0 20px}.lead{font-size:13px;max-width:90%}.hero-actions{margin:22px 0 13px;gap:18px}.primary,.secondary{padding:12px 20px;font-size:13px}.hero-art{max-width:470px;margin:0 9px 7px 0;border-radius:70px 8px 8px 8px;transform:rotate(.5deg)}.hero-art img{border-radius:58px 3px 0 0}.hero-art figcaption{font-size:10px;padding:10px 4px}.sticker{width:64px;height:64px;right:-10px;top:-15px;font-size:21px}.topic-strip{gap:13px;padding:17px 0}.topic-strip>div{display:block}.topic-strip b{font-size:20px;display:block;margin-bottom:3px}.topic-strip strong{font-size:10px}.topic-strip span{font-size:9px;line-height:1.5;display:block;margin-top:2px}.section{padding-top:39px}.section-head{display:block;margin-bottom:20px}.section-head h2{font-size:27px;margin-top:8px}.section-head>p{margin-top:12px;font-size:12px}.eyebrow{font-size:10px}.lesson-nav{gap:6px;margin-top:20px}.lesson-nav a{font-size:10px;padding:7px 10px}.story-top{padding:12px 16px;font-size:11px}.scene-dots button{width:28px;height:28px;font-size:10px}.scene-dots{gap:5px}.story-scene{grid-template-columns:1fr;min-height:0}.scene-art{padding:23px 21px;border-right:0;border-bottom:1px solid var(--ink);min-height:240px}.scene-copy{padding:24px 20px;min-height:340px}.scene-copy h3{font-size:25px;margin-bottom:17px}.bubble{font-size:13px;padding:11px 13px}.reveal{font-size:12px}.scene-controls{padding:13px 16px}.scene-controls span{display:none}.scene-controls .primary{font-size:12px;padding:10px 15px;min-height:42px}.packet{width:42px;height:53px;font-size:9px}.packet b{font-size:12px}.recipe-card{padding:14px}.packet-label{font-size:10px}.lab{grid-template-columns:1fr}.lab-controls,.lab-display{padding:24px 21px}.lab-controls h3{font-size:25px}.control{margin-top:22px}.lab-controls>p{font-size:12px}.formula{font-size:28px}.challenge{grid-template-columns:1fr;gap:25px}.quiz-aside{padding:20px;display:grid;grid-template-columns:1fr 1fr;gap:8px 20px}.quiz-aside>.eyebrow{grid-column:1/-1}.score{margin:0;font-size:41px}.quiz-aside>p{font-size:11px;align-self:center}.quiz-dots{grid-column:1/-1;margin:7px 0}.completion{grid-column:1/-1;margin-top:5px}.choices{gap:7px}.choice{padding:11px 9px;font-size:12px;min-height:63px}.choice[aria-pressed=true]{padding:10px 8px}.question h3{font-size:15px}.question-actions{gap:11px}.notebook{grid-template-columns:1fr;padding:24px 20px;gap:18px}.notebook h3{font-size:26px}.takeaway{font-size:13px;padding-left:18px}.route-row{grid-template-columns:28px 1fr 76px;gap:11px;padding:17px 0}.route-row p{grid-column:2/3;font-size:11px}.route-row h3{font-size:14px}.route-row .num{font-size:24px;align-self:start}.route-row .status{grid-column:3;grid-row:1/3;align-self:center;padding:4px 9px;font-size:9px}.route-row{position:relative}.route-row .status{grid-row:auto}.route-row p{grid-row:2;margin-top:-6px}.parents{padding:16px;margin:29px 0 34px;font-size:11px}.parents ul{padding-left:18px}.footer{font-size:10px;gap:14px}.footer .saved-note{order:3;width:100%}.art-caption{font-size:9px}}
@media(max-width:355px){.shell{padding:0 14px}.hero h1{font-size:39px}.brand{font-size:24px}.brand small{font-size:7px}.brand .brand-icon{display:none}.story-top{padding:12px}.scene-copy{padding:22px 15px}.scene-art{padding:20px 14px}.packet{width:37px;height:50px}.recipe-label{font-size:11px}.choice{font-size:11px}.question-actions .text-button{font-size:11px}.hero .lead{max-width:100%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{animation:none!important;transition:none!important}}
@media print{body{background:white;font-size:12px}.mast-right,.hero-actions,.lesson-nav,.scene-controls,.scene-dots,.control input,.presets,.question-actions,.parents,.footer,.sticker{display:none}.shell{max-width:100%;padding:0}.hero{padding:15px 0;grid-template-columns:1fr 1fr}.hero h1{font-size:35px}.section{padding-top:25px;break-inside:avoid}.story-scene{min-height:0}.scene-copy{padding:20px}.hero-art{box-shadow:none}.notebook{box-shadow:none}.choices{grid-template-columns:repeat(3,1fr)}.challenge{grid-template-columns:160px 1fr}.question{break-inside:avoid}}
