@import "https://fonts.googleapis.com/css2?family=Atkinson+Hyperlegible:wght@400;700&family=Nunito:wght@700;800&display=swap";:root{--colour-forest:#245c52;--colour-leaf:#3d8778;--colour-sun:#f6c85f;--colour-coral:#ed8068;--colour-ink:#243c3a;--colour-paper:#fffdf8;--colour-cream:#f8f1df;--colour-mint:#e9f5f0;--font-heading:"Nunito", system-ui, sans-serif;--font-body:"Atkinson Hyperlegible", system-ui, sans-serif;--radius-lg:28px;--radius-md:16px;--shadow-card:0 18px 50px #245c521f}*{box-sizing:border-box}html{background:var(--colour-cream);min-width:320px}body{min-width:320px;min-height:100vh;color:var(--colour-ink);font-family:var(--font-body);background:radial-gradient(circle at 7% 16%, #f6c85f47 0 70px, transparent 71px), radial-gradient(circle at 92% 72%, #a9d7da6b 0 95px, transparent 96px), var(--colour-cream);margin:0}button,input{font:inherit}button,a{-webkit-tap-highlight-color:transparent}button:focus-visible,a:focus-visible,input:focus-visible,[tabindex]:focus-visible{outline:4px solid var(--colour-sun);outline-offset:3px}.app-shell{flex-direction:column;width:min(100% - 32px,1040px);min-height:100vh;margin:0 auto;display:flex}.brand-bar{justify-content:space-between;align-items:center;gap:24px;min-height:98px;display:flex}.brand{color:var(--colour-forest);align-items:center;gap:11px;text-decoration:none;display:flex}.brand__mark{aspect-ratio:1;color:#fff;background:var(--colour-forest);width:48px;font:800 26px var(--font-heading);border-radius:50% 50% 44% 56%;place-items:center;display:grid;transform:rotate(-5deg);box-shadow:inset -6px -5px #ffffff1c}.brand strong,.brand small{line-height:1;display:block}.brand strong{font:800 22px var(--font-heading)}.brand small{letter-spacing:.08em;text-transform:uppercase;margin-top:5px;font-size:13px}.site-nav{background:#ffffff7a;border:1px solid #245c5214;border-radius:999px;align-items:center;gap:6px;padding:5px;display:flex}.site-nav a{color:#526b67;border-radius:999px;padding:9px 14px;font-weight:700;text-decoration:none}.site-nav a:hover,.site-nav a.active{color:var(--colour-forest);background:#fff;box-shadow:0 4px 14px #245c5214}.subject-pill{color:var(--colour-forest);background:#ffffffa6;border-radius:99px;padding:9px 15px;font-weight:700}.card{border-radius:var(--radius-lg);background:var(--colour-paper);width:100%;box-shadow:var(--shadow-card);border:1px solid #245c5217;margin:auto 0;padding:clamp(28px,5vw,64px)}h1{color:var(--colour-forest);font:800 clamp(38px, 7vw, 66px)/1.02 var(--font-heading);letter-spacing:-.035em;margin:8px 0 14px}.eyebrow,.question-prompt{color:var(--colour-leaf);font:800 15px var(--font-heading);letter-spacing:.1em;text-transform:uppercase;margin:0}.lead{max-width:700px;margin:0 0 30px;font-size:clamp(19px,2.4vw,24px);line-height:1.45}.intro-card{position:relative;overflow:hidden}.intro-card:after{content:"10";color:#3d877812;font:800 240px var(--font-heading);pointer-events:none;position:absolute;top:-55px;right:-15px}.example{z-index:1;border-radius:var(--radius-md);background:var(--colour-mint);grid-template-columns:minmax(240px,330px) 1fr;align-items:center;gap:clamp(24px,5vw,55px);margin:35px 0;padding:clamp(20px,4vw,34px);display:grid;position:relative}.example span,.example strong{display:block}.example span{color:var(--colour-leaf);font-weight:700}.example strong{color:var(--colour-forest);font:800 32px var(--font-heading);margin:4px 0}.example p{margin:0;line-height:1.4}.ten-frame{border:3px solid var(--colour-forest);background:#fff;border-radius:12px;grid-template-columns:repeat(5,1fr);gap:7px;width:min(100%,330px);padding:10px;display:grid}.ten-frame__cell{aspect-ratio:1;background:#fff;border:2px solid #b7ccc6;border-radius:9px;display:block}.ten-frame__cell--filled{border-color:var(--colour-coral);background:var(--colour-coral);box-shadow:inset 0 -4px #803b2c24}.button{min-height:52px;font:800 18px var(--font-heading);cursor:pointer;border:0;border-radius:14px;justify-content:center;align-items:center;gap:12px;padding:13px 24px;text-decoration:none;transition:transform .15s,box-shadow .15s,background .15s;display:inline-flex}.button:hover:not(:disabled){transform:translateY(-2px)}.button--primary{color:#fff;background:var(--colour-forest);box-shadow:0 8px #173e37}.button--primary:active:not(:disabled){transform:translateY(4px);box-shadow:0 4px #173e37}.button--secondary{color:var(--colour-forest);background:var(--colour-mint);margin-left:12px}.button:disabled{opacity:.4;cursor:not-allowed;box-shadow:none}.print-links{flex-wrap:wrap;gap:10px 18px;margin-top:30px;font-size:15px;display:flex}.print-links span{color:#647a76}.print-links a{color:var(--colour-forest);font-weight:700}.activity-card{max-width:900px;margin-inline:auto}.progress-row{color:#607571;justify-content:space-between;font-weight:700;display:flex}.progress-track{background:#e5ebe7;border-radius:99px;height:9px;margin-top:9px;overflow:hidden}.progress-track span{border-radius:inherit;background:var(--colour-leaf);height:100%;transition:width .3s;display:block}.question-layout{grid-template-columns:1fr minmax(250px,330px);align-items:center;gap:44px;margin:48px 0 38px;display:grid}.equation{align-items:center;gap:clamp(10px,2vw,20px);margin:10px 0 0;font-size:clamp(46px,8vw,74px);display:flex}.equation__blank{aspect-ratio:1;border:3px dashed var(--colour-coral);width:1.25em;color:var(--colour-coral);background:#fff5ed;border-radius:18px;place-items:center;display:grid}.answer-area{border-top:2px solid var(--colour-cream);padding-top:30px}.choices{grid-template-columns:repeat(3,1fr);gap:14px;max-width:510px;display:grid}.choice{min-height:74px;color:var(--colour-forest);font:800 30px var(--font-heading);cursor:pointer;background:#fff;border:2px solid #c6d7d2;border-radius:16px}.choice:hover{border-color:var(--colour-leaf);background:var(--colour-mint)}.choice--selected{border:3px solid var(--colour-forest);background:var(--colour-mint);box-shadow:0 0 0 3px #3d877826}.choice:disabled{cursor:default;opacity:1}.typed-answer{color:var(--colour-forest);font:800 23px var(--font-heading);align-items:center;gap:18px;display:flex}.typed-answer input{width:110px;height:70px;color:var(--colour-forest);text-align:center;font:800 30px var(--font-heading);background:#fff;border:3px solid #c6d7d2;border-radius:16px}.feedback-space{align-items:center;min-height:68px;display:flex}.feedback{align-items:center;gap:10px;margin:12px 0 0;font-weight:700;display:flex}.feedback span{color:#fff;border-radius:50%;place-items:center;width:30px;height:30px;display:grid}.feedback--correct{color:var(--colour-forest)}.feedback--correct span{background:var(--colour-leaf)}.feedback--try{color:#944735}.feedback--try span{background:var(--colour-coral)}.complete-card{text-align:center;max-width:760px;margin-inline:auto}.complete-card .lead{margin-inline:auto}.celebration{aspect-ratio:1;width:90px;color:var(--colour-forest);background:var(--colour-sun);border-radius:50%;place-items:center;margin:0 auto 20px;font-size:48px;display:grid;transform:rotate(-7deg)}.result{background:var(--colour-mint);border-radius:18px;justify-content:center;align-items:center;gap:18px;width:min(100%,340px);margin:25px auto 35px;padding:22px;display:flex}.result strong{color:var(--colour-forest);font:800 54px var(--font-heading)}.result span{text-align:left;max-width:100px;font-weight:700}footer{color:#6b807c;text-align:center;justify-content:center;align-items:center;gap:8px;min-height:82px;font-size:14px;display:flex}.page-stack{gap:clamp(72px,10vw,120px);padding:clamp(30px,5vw,72px) 0 56px;display:grid}.home-hero{grid-template-columns:minmax(0,1.1fr) minmax(320px,.9fr);align-items:center;gap:clamp(44px,8vw,100px);min-height:590px;display:grid}.home-hero__copy h1{max-width:700px;font-size:clamp(52px,8vw,88px)}.home-hero__copy .lead{max-width:620px}.preview-note{color:#667b77;margin:24px 0 0;font-size:14px}.home-demo{background:var(--colour-paper);box-shadow:var(--shadow-card);border:1px solid #245c5217;border-radius:42px 42px 90px;padding:clamp(30px,5vw,48px);position:relative;transform:rotate(1.5deg)}.home-demo:before{content:"";background:#f6c85fb3;border-radius:2px;width:92px;height:22px;position:absolute;top:-10px;left:50%;transform:translate(-50%)rotate(-2deg)}.home-demo__tag{color:var(--colour-leaf);font:800 14px var(--font-heading);letter-spacing:.07em;text-transform:uppercase;margin-bottom:26px;display:inline-block}.home-demo .ten-frame{width:100%}.home-demo__equation{color:var(--colour-forest);font:800 38px var(--font-heading);justify-content:center;align-items:center;gap:14px;margin:26px 0 12px;display:flex}.mini-blank{color:#fff;background:var(--colour-coral);border-radius:12px;place-items:center;width:1.3em;height:1.3em;display:grid}.home-demo p{color:#667b77;text-align:center;margin:0}.principles{background:var(--colour-forest);color:#fff;border-radius:34px;grid-template-columns:.75fr 1.25fr;gap:clamp(36px,7vw,90px);padding:clamp(36px,6vw,70px);display:grid}.principles h2,.resource-card h2{font:800 clamp(32px, 4vw, 48px)/1.1 var(--font-heading);letter-spacing:-.025em;margin:8px 0 0}.principles h2{color:#fff}.principles .eyebrow{color:#aee0d4}.principle-grid{grid-template-columns:repeat(3,1fr);gap:24px;display:grid}.principle-grid article{border-left:1px solid #ffffff3b;padding-left:20px}.principle-grid span{color:var(--colour-sun);font:800 13px var(--font-heading)}.principle-grid h3{font:800 20px var(--font-heading);margin:12px 0 8px}.principle-grid p{color:#d8ebe6;margin:0;line-height:1.5}.page-intro{max-width:850px}.page-intro h1{font-size:clamp(48px,7vw,76px)}.review-banner{color:#715629;background:#fff4d8;border-radius:12px;margin:4px 0 0;padding:11px 15px;font-size:14px;display:inline-flex}.free-page{gap:clamp(42px,6vw,72px)}.resource-card{background:var(--colour-paper);box-shadow:var(--shadow-card);border:1px solid #245c5217;border-radius:30px;grid-template-columns:minmax(280px,.8fr) minmax(0,1.2fr);display:grid;overflow:hidden}.resource-card__visual{background:var(--colour-mint);align-content:center;place-items:center;gap:25px;min-height:430px;padding:clamp(30px,5vw,55px);display:grid}.resource-card__visual .ten-frame{width:min(100%,320px)}.resource-badge{color:var(--colour-forest);font:800 13px var(--font-heading);background:#fff;border-radius:999px;justify-self:start;padding:8px 12px}.resource-equation{color:var(--colour-forest);font:800 36px var(--font-heading)}.resource-equation span{border:2px dashed var(--colour-coral);width:1.25em;height:1.25em;color:var(--colour-coral);border-radius:10px;place-items:center;display:inline-grid}.resource-card__copy{flex-direction:column;justify-content:center;padding:clamp(34px,6vw,72px);display:flex}.resource-card__copy h2{color:var(--colour-forest)}.resource-card__copy>p:not(.eyebrow){max-width:600px;margin:18px 0;font-size:19px;line-height:1.5}.resource-list{gap:9px;margin:0 0 28px;padding:0;list-style:none;display:grid}.resource-list li:before{content:"✓";color:var(--colour-leaf);margin-right:10px;font-weight:700}.resource-actions{flex-wrap:wrap;align-items:center;gap:18px;display:flex}.text-link{color:var(--colour-forest);text-underline-offset:4px;font-weight:700}.activity-page{flex-direction:column;flex:1;padding:12px 0 30px;display:flex}.activity-page>.card{margin:auto 0}.back-link{color:var(--colour-forest);cursor:pointer;background:0 0;border:0;align-self:flex-start;margin:0 0 14px;padding:9px 0;font-weight:700}.not-found-card{max-width:760px;margin:auto}@media (width<=680px){.app-shell{width:min(100% - 20px,1040px)}.brand-bar{min-height:82px}.brand__mark{width:41px}.brand strong{font-size:19px}.brand small{font-size:10px}.site-nav a{padding:8px 10px;font-size:13px}.site-nav a:first-child{display:none}.subject-pill{padding:8px 10px;font-size:13px}.card{border-radius:22px;padding:26px 20px}.example,.question-layout{grid-template-columns:1fr}.example{gap:18px;margin:25px 0}.question-layout{gap:24px;margin:34px 0 26px}.question-layout .ten-frame{max-width:280px}.equation{justify-content:center}.question-prompt{text-align:center}.choices{gap:9px}.choice{min-height:66px}.actions .button,.complete-card .button{width:100%}.button--secondary{margin:16px 0 0}.print-links{display:grid}footer{flex-wrap:wrap;padding:18px 0;line-height:1.4}.page-stack{gap:62px;padding-top:28px}.home-hero{grid-template-columns:1fr;gap:54px;min-height:0}.home-hero__copy h1{font-size:clamp(48px,16vw,66px)}.home-demo{border-radius:28px 28px 56px;padding:28px 22px}.principles{grid-template-columns:1fr;padding:34px 24px}.principle-grid{grid-template-columns:1fr}.principle-grid article{padding:2px 0 2px 18px}.resource-card{grid-template-columns:1fr}.resource-card__visual{min-height:330px}.resource-card__copy{padding:34px 22px 40px}.resource-actions .button{width:100%}.activity-page{padding-top:2px}}@media (width>=681px) and (width<=900px){.home-hero{grid-template-columns:1fr 320px;gap:40px}.principles{grid-template-columns:1fr}.resource-card{grid-template-columns:.9fr 1.1fr}}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition:none!important}}