@font-face{font-family:Brush;src:url(assets/CaveatBrush-Regular.ttf)}@font-face{font-family:Kalam;src:url(assets/Kalam-Regular.ttf)}@font-face{font-family:Kalam;src:url(assets/Kalam-Bold.ttf);font-weight:700}
:root{--ink:#193a83;--blue:#163ba0;--teal:#0b756e;--mint:#13bfae;--yellow:#ffe148;--pink:#f383a1;--paper:#fffdf5;--bg:#f5f3eb;--line:#d9ded7}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.55 system-ui,-apple-system,Segoe UI,sans-serif}button,a,input{touch-action:manipulation}button{font:inherit;cursor:pointer}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #a32658;outline-offset:4px}button:disabled{cursor:default;opacity:.65}.skip{position:fixed;top:-80px;left:15px;padding:12px;background:var(--yellow);z-index:20}.skip:focus{top:10px}.sidebar{width:260px;background:var(--paper);position:fixed;inset:0 auto 0 0;border-right:1px solid var(--line);padding:35px 22px;display:flex;flex-direction:column}.brand{display:flex;gap:11px;text-decoration:none;align-items:center;font:25px Brush}.brand small{display:block;font:9px/2 system-ui;letter-spacing:1.1px;margin-top:4px}.brand-mark{border:2px solid var(--blue);width:43px;height:46px;transform:rotate(-6deg);border-radius:9px;font:37px Brush;text-align:center;position:relative;background:#e2f5ee}.brand-mark span{font:24px Brush;color:#b13461;position:absolute;right:-8px;top:-12px}.volume{font-size:11px;letter-spacing:1.8px;margin:40px 10px 24px;font-weight:700}.volume span{display:block;letter-spacing:1px;font-size:10px;opacity:.7;margin-top:5px}nav{display:grid;gap:9px}nav button{display:flex;align-items:center;gap:12px;border:0;background:none;color:var(--ink);text-align:left;padding:13px 11px;border-radius:10px;min-height:49px;font-size:14px;font-weight:600}nav button:hover{background:#eef2eb}nav button.active{background:var(--blue);color:white;box-shadow:3px 4px 0 #d4ddd9}.nav-icon{font:25px Brush;width:25px}.nav-count{margin-left:auto;font-size:11px;white-space:nowrap}.sidebar-note{margin:auto 10px 35px;padding-top:40px;font:19px/1.4 Kalam;position:relative}.sidebar-note strong{font:24px Brush}.sidebar-note p{margin:6px 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6px 0 #d5ded2;overflow:hidden}.hero-copy{max-width:66%;position:relative;z-index:1}.hero h1{font:clamp(44px,4.5vw,68px)/1 Brush;margin:5px 0 17px;letter-spacing:-.6px}.hero h1 span{position:relative;white-space:nowrap}.hero h1 span:after{content:"";position:absolute;height:7px;background:var(--yellow);bottom:-7px;left:0;right:0;transform:rotate(-1deg);border-radius:45%}.hero p{font:20px/1.4 Kalam;margin:0;max-width:440px}.hero img{width:34%;max-height:220px;object-fit:contain;align-self:end;margin:0 -6px -31px 0;filter:drop-shadow(0 4px 0 #167b7833)}.hero .sticker{position:absolute;top:21px;right:23px;transform:rotate(6deg);background:var(--yellow);padding:4px 12px;font:18px Brush;border:1px solid var(--ink);z-index:2}.section-title{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:34px 0 16px}.section-title h2{font:31px/1.2 Brush;margin:0}.step-tag{font-size:10px;letter-spacing:1px;white-space:nowrap;color:#52646b}.two-col{display:grid;grid-template-columns:minmax(0,1.28fr) minmax(240px,1fr);gap:22px}.paper{background:var(--paper);border:1.5px solid var(--ink);border-radius:7px 12px 8px 6px;padding:25px;box-shadow:3px 4px 0 #e1e1d5;position:relative}.paper h2,.paper h3{font:29px/1.2 Brush;margin:0 0 16px}.paper p{margin:10px 0}.small{font-size:13px;line-height:1.55;color:#52646b}.hand{font-family:Kalam;font-size:20px}.tape{display:inline-block;background:var(--yellow);padding:3px 12px;transform:rotate(-2deg);font:23px Brush;margin:-3px 0 15px}.tape.pink{background:#ffc1d2}.tape.mint{background:#b5eddb}.fraction-lab{margin:15px 0 20px}.fraction-bar{display:flex;min-height:83px;border:2px solid var(--blue);border-radius:5px;overflow:hidden;background:white}.part{min-width:0;flex:1;border:0;border-right:2px solid var(--blue);background:#fffdf7;padding:0;position:relative;min-height:80px}.part:last-child{border-right:0}.part.selected{background:#77c8ee}.part.selected:after{content:"";position:absolute;inset:7px;background:repeating-linear-gradient(135deg,transparent 0px,transparent 5px,#ffffff3b 6px,#ffffff3b 7px)}.part:hover{box-shadow:inset 0 0 0 4px #ffe14899}.lab-controls{display:flex;justify-content:space-between;align-items:center;gap:12px;margin:18px 0;font-size:13px}.stepper{display:flex;align-items:center;border:1px solid var(--line);border-radius:8px;background:white;overflow:hidden}.stepper button{background:transparent;border:0;color:var(--blue);min-width:42px;min-height:42px;font-size:22px}.stepper output{min-width:35px;text-align:center;font-weight:700}.fraction-result{display:flex;gap:20px;align-items:center;background:#e4f4ed;padding:15px;border-radius:9px}.frac{display:inline-flex;flex-direction:column;align-items:center;vertical-align:middle;font-family:Kalam;font-size:32px;line-height:1.05;min-width:35px;margin:0 7px}.frac .num{border-bottom:2px solid currentColor;width:100%;text-align:center;padding:0 5px 4px}.frac .den{padding:4px 5px 0}.fraction-result p{font:20px/1.4 Kalam;margin:0}.rule-list{padding:0;list-style:none;margin:0}.rule-list li{border-bottom:1px solid var(--line);padding:14px 0;display:flex;gap:14px}.rule-list li:last-child{border:0}.rule-list b{font:26px Brush;display:block;margin-bottom:5px}.number-circle{flex:0 0 29px;width:29px;height:29px;display:grid;place-items:center;background:var(--yellow);border:1px solid var(--ink);border-radius:50%;font-size:14px;font-weight:700;line-height:1}.note{background:#fff2b5;border-left:4px solid #c4a231;padding:12px 15px;font:18px/1.5 Kalam;border-radius:4px}.equivalence{display:grid;grid-template-columns:1fr 1fr;gap:22px;align-items:center}.eq-figure{text-align:center}.mini-bar{display:flex;border:2px solid var(--blue);height:42px;border-radius:3px;overflow:hidden}.mini-bar i{flex:1;border-right:1px solid var(--blue);background:var(--paper)}.mini-bar i:last-child{border:0}.mini-bar i.on{background:#77c8ee}.actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-top:22px}.btn{display:inline-flex;justify-content:center;align-items:center;gap:10px;border:1.5px solid var(--blue);background:var(--blue);color:white;border-radius:9px;padding:12px 18px;min-height:47px;font-weight:650;font-size:14px;text-decoration:none}.btn:hover{background:#0b297f}.btn.secondary{background:var(--paper);color:var(--blue)}.btn.secondary:hover{background:#e9f2ea}.btn.yellow{background:var(--yellow);color:var(--blue)}.btn.text-btn{border:0;background:none;color:var(--blue);text-decoration:underline;padding-left:0}.page-heading h1{font:50px/1.1 Brush;margin:5px 0 12px}.page-heading p{font:21px Kalam;margin:0 0 25px}.quiz-layout{display:grid;grid-template-columns:minmax(0,1fr) 235px;gap:23px;align-items:start}.quiz-progress{height:7px;border-radius:20px;background:#e0e6dd;overflow:hidden;margin:15px 0 22px}.quiz-progress div{height:100%;background:var(--teal);transition:width .3s}.quiz-meta{display:flex;justify-content:space-between;gap:10px;font-size:11px;font-weight:650;color:#536567}.question-title{font:32px/1.2 Brush!important;margin:15px 0 20px!important}.quiz-visual{padding:12px 20px 23px;text-align:center}.quiz-visual .mini-bar{max-width:350px;margin:5px auto}.equation{font:30px Kalam}.options{display:grid;grid-template-columns:1fr 1fr;gap:12px}.option{border:1.5px solid #a8b9c4;background:white;color:var(--ink);border-radius:9px;min-height:78px;padding:14px 10px;font:25px Kalam;position:relative}.option:hover{border-color:var(--blue);background:#f0f4fc}.option[aria-pressed=true]{border:2px solid var(--blue);background:#e9eefb}.option.correct{border:2px solid #158065;background:#d9f2e8}.option:disabled{opacity:1}.option .frac{font-size:26px}.feedback{margin-top:18px;background:#e4f4ed;border-left:4px solid #138066;padding:16px;border-radius:5px}.feedback.retry{background:#fff2c5;border-color:#a47c04}.feedback strong{display:block;margin-bottom:6px}.feedback p{margin:6px 0}.feedback ol{padding-left:24px;font-size:14px}.hint-box{background:#fff3b3;padding:14px;border-radius:8px;margin-top:15px;font-size:14px}.hint-box p{margin:5px 0}.quiz-aside h3{font:27px Brush;margin:0 0 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.btn{font-family:system-ui;font-size:13px}.map-equation{padding:13px;background:#e9f3ed;border-radius:8px;min-height:80px;display:flex;justify-content:center;align-items:center}.metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:25px 0}.metric{background:var(--paper);padding:23px;border:1px solid var(--ink);border-radius:10px}.metric strong{display:block;font:49px Brush}.metric span{font-size:13px}.progress-list{list-style:none;padding:0;margin:0}.progress-list li{display:flex;justify-content:space-between;align-items:center;gap:16px;border-bottom:1px solid var(--line);padding:13px 0}.progress-list li:last-child{border:0}.progress-list button{border:0;background:none;text-align:left;color:var(--blue);font-weight:600;padding:7px 0}.status{font-size:11px;white-space:nowrap;border-radius:20px;padding:3px 9px;background:#e9ece7}.status.done{background:#d8eee3;color:#176446}.empty-note{font:22px Kalam}footer{border-top:1px solid var(--line);padding:20px 42px;display:flex;justify-content:space-between;gap:15px;color:#5c6b71;font-size:10px}footer b{color:var(--teal);margin:0 5px}.reset-confirm{background:#fff0d5;padding:15px;border-radius:8px;margin-top:12px}.sr-only{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}
@media(min-width:1500px){main{padding-top:42px}.hero{min-height:280px}.hero img{max-height:245px}}
@media(max-width:1100px){.sidebar{width:220px;padding:28px 15px}.workspace{margin-left:220px}.brand{font-size:22px}.topbar{padding:0 26px}main{padding:25px 26px 45px}.two-col{grid-template-columns:1fr}.quiz-layout{grid-template-columns:1fr}.quiz-aside{display:flex;align-items:center;gap:15px;padding:16px}.quiz-aside h3{font-size:23px;margin:0}.q-dots{grid-template-columns:repeat(10,1fr);flex:1}.aside-tip{display:none}.hero-copy{max-width:68%}footer{padding:18px 26px}}
@media(max-width:760px){.sidebar{position:relative;width:100%;padding:18px 17px 12px;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:23px}.brand-mark{height:37px;width:35px;font-size:30px}.brand small{font-size:8px}.volume,.sidebar-note,.edition{display:none}nav{display:grid;grid-template-columns:repeat(4,1fr);gap:5px;margin-top:18px}nav button{padding:9px 3px;min-height:61px;flex-direction:column;gap:2px;text-align:center;font-size:10px;line-height:1.2}.nav-icon{font-size:22px}.nav-count{display:none}.workspace{margin-left:0}.topbar{height:52px;padding:0 18px;font-size:10px}.topbar span:not(.calm){margin:0 5px}.calm{font-size:10px}main{padding:20px 17px 35px}.hero{padding:23px 19px 24px;min-height:237px;overflow:visible;align-items:start}.hero-copy{max-width:100%}.hero h1{font-size:47px;margin-top:20px}.hero p{font-size:19px;max-width:66%}.hero img{position:absolute;width:33%;right:9px;bottom:0;margin:0;max-height:155px}.hero .sticker{font-size:14px;top:11px;right:12px}.hero .eyebrow{font-size:9px;letter-spacing:1.2px}.section-title{margin-top:29px}.section-title h2{font-size:29px}.step-tag{font-size:9px}.paper{padding:20px}.lab-controls{flex-wrap:wrap}.fraction-result{gap:10px;padding:13px}.fraction-result p{font-size:19px}.equivalence{grid-template-columns:1fr;gap:20px}.map-grid{grid-template-columns:1fr}.page-heading h1{font-size:41px}.page-heading p{font-size:19px}.quiz-aside{flex-direction:column;align-items:stretch;gap:10px}.q-dots{width:100%;gap:5px}.q-dot{min-width:0;padding:0;min-height:34px}.question-title{font-size:29px!important}.quiz-visual{padding:10px 0 20px}.metrics{gap:9px}.metric{padding:14px 11px}.metric strong{font-size:38px}.metric span{font-size:11px}.progress-list li{gap:10px}.progress-list button{font-size:13px}.status{font-size:10px}footer{padding:17px;flex-direction:column;gap:7px}.btn{padding:11px 14px;font-size:13px}.actions{gap:10px}.options{gap:10px}.option{min-height:76px}.hand{font-size:19px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}