:root{color-scheme:light;--bg:#f5f3ee;--paper:#fffefa;--ink:#272838;--muted:#666776;--line:#dfded7;--purple:#654bd4;--purple-light:#eeebff;--teal:#147a68;--teal-light:#ddf3e9;--coral:#c95640;--coral-light:#ffebe4;--blue:#346ab1;--blue-light:#e5efff;--amber:#8d641a;--amber-light:#fff0cc;--pink:#a34378;--pink-light:#f9e7f1;--accent:var(--purple);--tint:var(--purple-light)}
*{box-sizing:border-box}body{margin:0;font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--bg)}button,input,select{font:inherit}button,a,input,select,summary{-webkit-tap-highlight-color:transparent}button{cursor:pointer;touch-action:manipulation}button:disabled{cursor:default}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--purple);outline-offset:4px}button{min-height:48px}a{color:inherit}h1,h2,h3,p{margin:0}h2,h3{line-height:1.2}h2{font-size:clamp(1.65rem,3.3vw,2.3rem);letter-spacing:-.04em}h3{font-size:1.2rem}p+p{margin-top:12px}[hidden]{display:none!important}.page{max-width:1240px;margin:auto;padding:0 38px}.skip{position:absolute;top:-80px;left:20px;z-index:9;padding:12px;background:var(--paper)}.skip:focus{top:8px}.topbar{min-height:100px;display:flex;align-items:center;justify-content:space-between;gap:20px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;font-weight:700;font-size:.95rem}.brand small{display:block;font-size:.6rem;font-weight:650;letter-spacing:.15em;margin-top:3px;color:var(--muted)}.brand-icon{display:flex;align-items:center;justify-content:center;width:44px;height:44px;background:var(--ink);color:white;border-radius:14px;font-size:26px;font-weight:800;letter-spacing:-.15em;padding-right:4px}.brand-icon>span{color:#c4ee79;font-size:21px;align-self:flex-start;margin-top:5px}.save-label{font-size:.73rem;color:var(--muted)}.hero{display:grid;grid-template-columns:1.2fr 1fr;align-items:center;gap:30px;padding:48px 0 42px}.eyebrow{font-size:.66rem;letter-spacing:.16em;font-weight:750;color:var(--muted)}.status-dot{width:7px;height:7px;display:inline-block;border-radius:50%;background:var(--teal);margin-right:7px}h1{font-size:clamp(2.8rem,6vw,4.75rem);line-height:1.02;letter-spacing:-.065em;margin:16px 0 20px;font-weight:800}h1>span{color:var(--purple)}.hero-lead{color:var(--muted);font-size:1.07rem}.hero-tags{display:flex;flex-wrap:wrap;gap:10px 22px;margin-top:23px;font-size:.72rem;font-weight:600}.hero-tags span:first-child{color:var(--teal)}.hero-art{height:292px;position:relative;isolation:isolate;background-image:radial-gradient(#c8c4d5 1px,transparent 1px);background-size:17px 17px;border-radius:50%;max-width:450px;width:100%;justify-self:end}.orbit{border:1px solid #d5d1e3;border-radius:50%;position:absolute;inset:15px 18px;transform:rotate(-25deg);z-index:-1}.orbit-two{inset:50px 0;transform:rotate(25deg)}.float-token{position:absolute;border:1px solid #ded9f2;border-radius:15px;background:var(--paper);font-size:1.5rem;font-weight:750;padding:10px 22px;box-shadow:0 7px 0 #e4e0ee}.token-one{top:24px;left:12px;transform:rotate(-13deg);color:var(--purple)}.token-two{top:25px;right:8px;transform:rotate(12deg);color:var(--purple)}.token-three{bottom:42px;right:4px;transform:rotate(-8deg);background:var(--teal-light);color:var(--teal);box-shadow:0 6px 0 #c1e3d6;border-color:#badfce}.art-caption{position:absolute;bottom:-10px;left:0;right:0;text-align:center;font-size:.73rem;color:var(--muted)}.robot{position:absolute;width:155px;height:200px;left:calc(50% - 77px);top:48px;transform:rotate(-5deg)}.antenna{position:absolute;width:5px;height:26px;left:75px;top:0;background:#8070ab}.antenna i{position:absolute;width:14px;height:14px;background:#b9dc79;border:3px solid #7f9e4c;border-radius:50%;left:-5px;top:-5px}.robot-head{position:absolute;width:145px;height:100px;top:20px;left:5px;background:#d0c5ef;border:3px solid #8d7bb2;border-radius:32px 32px 24px 24px;box-shadow:inset 0 7px 0 #e7e0f7,0 6px 0 #a495c2;z-index:2}.robot-face{position:absolute;inset:19px 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var(--accent)}.workshop-icon{display:inline-flex;width:33px;height:33px;border-radius:10px;align-items:center;justify-content:center;background:var(--tint);color:var(--accent);font-size:1.45rem;font-weight:700}.workshop-number{position:absolute;right:13px;top:15px;color:var(--muted);font-size:.68rem}.workshop-link strong{display:block;font-size:.75rem;margin-top:9px;line-height:1.35}.workshop-progress{display:block;font-size:.63rem;color:var(--muted);margin-top:4px}.workshop-link.earned .workshop-number{color:var(--teal);font-weight:700}[data-color=coral]{--accent:var(--coral);--tint:var(--coral-light)}[data-color=teal]{--accent:var(--teal);--tint:var(--teal-light)}[data-color=blue]{--accent:var(--blue);--tint:var(--blue-light)}[data-color=amber]{--accent:var(--amber);--tint:var(--amber-light)}[data-color=pink]{--accent:var(--pink);--tint:var(--pink-light)}#workbench{background:var(--paper);border:1px solid 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ease}.sr-only{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@keyframes flip{0%{transform:rotateY(0)}50%{transform:rotateY(90deg) translateY(-5px)}100%{transform:rotateY(0)}}@keyframes join{0%{transform:translateY(-14px) scale(.9);opacity:.2}70%{transform:translateY(3px) scale(1.04)}100%{transform:none;opacity:1}}@keyframes slide-in{from{transform:translateY(-18px);opacity:.2}to{transform:translateY(0);opacity:1}}@keyframes expand{from{transform:scale(.83);opacity:.4}to{transform:scale(1);opacity:1}}
@media(min-width:1400px){.page{padding:0 45px}}@media(max-width:1000px){.page{padding:0 25px}.discover-layout{grid-template-columns:minmax(0,1fr) 250px}.guide{padding:24px 18px}.experiment{padding:22px 20px}.workshop-nav{gap:7px}.workshop-link{padding:12px 9px}.hero-art{height:280px}.hero{gap:18px}.hero-tags{font-size:.68rem;gap:8px 15px}.workshop-link strong{font-size:.7rem}}@media(max-width:760px){.page{padding:0 18px}.topbar{min-height:80px}.save-label{max-width:130px;text-align:right;font-size:.65rem}.hero{padding:32px 0 30px;grid-template-columns:1.2fr .8fr;gap:5px}.hero-art{height:225px}.robot{transform:scale(.8) rotate(-5deg);top:24px}.float-token{font-size:1rem;padding:8px 10px}.token-one{top:12px;left:0}.token-two{top:0;right:0}.token-three{bottom:15px;right:0}.art-caption{display:none}.hero-tags{display:none}.hero-lead{font-size:.92rem}.eyebrow{font-size:.58rem}h1{font-size:clamp(2.3rem,7.5vw,3.8rem)}.workshop-nav{grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.workshop-link{min-height:103px;padding:12px}.workshop-link strong{font-size:.75rem}.workshop-progress{font-size:.65rem}.discover-layout{grid-template-columns:1fr}.guide{border-left:0;border-top:1px solid var(--line);display:grid;grid-template-columns:1fr 1fr;gap:10px 24px;padding:20px 24px}.guide-heading{grid-column:1/-1;margin-bottom:0}.guide .insight{margin:0;padding:0;border:0}.guide .live-note{margin:0;grid-column:1/-1;min-height:0}.guide details{grid-column:1/-1;margin:0}.lesson-top{padding:24px}.mode-tabs{padding:0 24px;gap:23px}.lesson-symbol{width:55px;height:55px;font-size:2.5rem}.experiment{padding:22px 24px}.toolbox{grid-template-columns:1fr;padding-top:30px}.toolbox>div:first-child{grid-row:auto;margin-bottom:16px}.practice-wrap,.paper-wrap{padding:24px}.hero .eyebrow{letter-spacing:.1em}.journey-head p{max-width:230px}.grid-cell{min-height:82px}}
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@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media print{body{background:white;color:black;font-size:12pt}.topbar,.hero,.journey-head,.workshop-nav,.mode-tabs,.lesson-symbol,.toolbox,footer,.button-row,.paper-task details,.reflection,.skip,#panel-discover,#panel-practice{display:none!important}.page{padding:0;max-width:none}#workbench{border:0}.paper-wrap{padding:0}.lesson-top{padding:0 0 20px}#panel-paper{display:block!important}.paper-task{break-inside:avoid}.paper-lines{height:150px}.paper-intro{margin-bottom:15px}.paper-task .formula{color:black}}
/* Guided learning and the child's persistent garden. */
.top-actions{display:flex;align-items:center;gap:18px}.garden-open{display:flex;align-items:center;gap:9px;border:1px solid #c2d8be;border-radius:14px;background:#eaf3e3;color:#31513b;padding:10px 14px;font-size:.8rem;font-weight:700}.garden-open span{font-size:.67rem;color:#4e6853}.guided-wrap{padding:28px 30px 24px}.guided-heading{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:19px}.guided-heading h3{margin-top:8px;font-size:1.25rem}.guided-drop{font-size:.8rem;white-space:nowrap;color:var(--teal)}.guided-select-label{display:block;font-size:.8rem;font-weight:650;margin-bottom:6px}#guided-lesson{min-height:48px;padding:10px 13px;border:1px solid #c7c3d4;border-radius:10px;background:var(--paper);color:var(--ink);width:100%;max-width:650px;font-size:16px}.guided-progress{display:flex;gap:6px;margin:24px 0 19px;max-width:650px}.guided-progress span{height:5px;flex:1;border-radius:3px;background:#e5e0ed}.guided-progress 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var(--line);border-radius:14px;padding:16px 12px;min-width:0}.branch-member{display:inline-block;font-size:1.35rem;font-weight:750;color:var(--accent);background:var(--tint);border-radius:9px;padding:4px 14px}.branch-caption{display:block;margin:9px 0 6px;font-size:.7rem;color:var(--muted)}.branch-target strong{font-size:1.15rem;overflow-wrap:anywhere}.branch-plus{align-self:center;text-align:center;font-size:1.5rem}.split-groups{display:grid;grid-template-columns:1fr 1fr;gap:16px}.split-groups>div{padding:18px;background:var(--bg);border-radius:14px;text-align:center}.split-groups p{margin:10px 0;font-size:1.2rem}.split-groups strong{display:block;color:var(--accent);font-size:1.3rem;animation:slide-in .4s ease}.guided-line{display:block;width:100%;max-width:420px;margin:auto;overflow:visible}.guided-line text{font-size:14px;fill:var(--ink)}.line-journey{stroke-dasharray:300;animation:draw-branch .9s ease}.line-destination{animation:join .5s ease}.line-legend{display:flex;justify-content:center;gap:25px;font-size:.8rem}.mirror-controls{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:9px;margin-bottom:18px;font-size:.85rem}.mirror-controls button[aria-pressed=true]{background:var(--tint);border-color:var(--accent)}.mirror-result{text-align:center;font-size:1.15rem;font-weight:700;margin-top:15px}.mirror-result span{font-weight:400;color:var(--muted);margin:0 12px}.visual-caption{font-size:.82rem;text-align:center;color:var(--muted);margin-top:10px}.reward{position:relative;display:flex;gap:13px;align-items:center;flex-wrap:wrap;border-top:1px solid #bfd6c5;margin-top:15px;padding:16px 0 2px;color:#254c34}.reward strong{font-size:.92rem;margin:0!important}.reward p{font-size:.78rem;margin-top:3px;max-width:500px}.reward-icon{font-size:2rem}.reward button{margin-left:auto}.reward.new-gift{animation:join .55s ease}.reward-spark{position:absolute;right:40%;top:15px;font-size:1.5rem;color:#a26c10;pointer-events:none;animation:spark-rise 1.2s ease forwards}.reward-spark.second{right:30%;animation-delay:.12s}.reward .secondary{background:var(--paper)}#garden-dialog{background:#fffdf8;color:var(--ink);border:1px solid #d8dfcc;border-radius:24px;padding:25px;width:calc(100% - 32px);max-width:850px;max-height:calc(100dvh - 32px);overflow-y:auto;overscroll-behavior:contain}#garden-dialog::backdrop{background:#242d36a6;backdrop-filter:blur(3px)}.garden-header{display:flex;align-items:center;justify-content:space-between;gap:15px}.garden-header h2{font-size:1.7rem;margin-top:6px}.garden-header .secondary{flex-shrink:0}.garden-summary{display:flex;justify-content:space-between;gap:12px;margin-top:22px;font-size:.85rem}.garden-summary strong{color:var(--teal)}.garden-instruction{margin:12px 0;font-size:.88rem;min-height:44px}.garden-land{position:relative;border-radius:20px;overflow:hidden;background:linear-gradient(#e3f4f3 0%,#f2f7e6 27%,#e0edc5 28%,#c2dda3 100%);padding:60px 15px 20px}.garden-sky{position:absolute;inset:0 0 auto;display:flex;justify-content:space-around;height:55px;align-items:center;font-size:2rem;color:#d1a548;pointer-events:none}.garden-sky span:not(:first-child){color:white;font-size:2.8rem}.garden-plots{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:10px}.garden-plot{background:#f9fff53d;border:1px dashed #779663;border-radius:50% 50% 15px 15px;min-width:0;min-height:100px;padding:12px 4px 8px;color:#45633d;transition:background .2s}.garden-plot>span{display:block;font-size:2.7rem;line-height:1.3}.garden-plot>small{display:block;font-size:.61rem;line-height:1.3}.garden-plot.planted{border-color:transparent;background:#e9f4d269}.garden-plot.planted>span{animation:plant-grow .55s ease}.garden-plot:disabled{opacity:1}.garden-plot:not(:disabled):hover{background:#fffdf3a6}.garden-tools{display:flex;gap:14px;align-items:center;flex-wrap:wrap;margin-top:12px}.garden-tools>span{font-size:.73rem;color:var(--muted)}.garden-tools button{font-size:.75rem}.garden-tools button[aria-pressed=true]{border-color:var(--teal);background:var(--teal-light)}.collection-title{font-size:1rem;margin:23px 0 12px}.garden-collection{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:9px}.collection-item{border:1px solid #dde1d4;border-radius:14px;background:#f3f2eb;padding:12px 7px;color:var(--muted);min-width:0}.collection-item.owned{background:white;color:#36533f;border-color:#bacfb2}.collection-item>span{display:block;font-size:1.9rem}.collection-item strong{display:block;font-size:.74rem;margin-top:6px}.collection-item small{display:block;font-size:.64rem;margin-top:3px}.collection-item[aria-pressed=true]{border:2px solid var(--teal);background:var(--teal-light)}.garden-footnote{margin-top:18px;font-size:.76rem;color:var(--muted)}@keyframes draw-branch{from{stroke-dashoffset:250}to{stroke-dashoffset:0}}@keyframes plant-grow{from{transform:translateY(10px) scale(.5)}to{transform:none}}@keyframes spark-rise{0%{opacity:0;transform:translateY(10px) scale(.5)}25%{opacity:1}100%{opacity:0;transform:translateY(-45px) rotate(45deg) scale(1.2)}}
@media(max-width:850px){.top-actions{gap:8px;flex-direction:column;align-items:flex-end;padding:12px 0}.top-actions .save-label{max-width:none}.guided-wrap{padding:24px}.guided-options{grid-template-columns:1fr}.guided-option{min-height:52px}.garden-plots{grid-template-columns:repeat(4,minmax(0,1fr))}}
@media(max-width:600px){.mode-tabs{display:grid;grid-template-columns:1fr 1fr;gap:0 15px}.mode-tabs button{text-align:center;font-size:.82rem}.guided-wrap{padding:21px 17px}.guided-heading{align-items:flex-start}.guided-heading h3{font-size:1.05rem}.guided-heading .eyebrow{font-size:.56rem}.guided-before,.guided-after{padding:14px}.guided-before .formula,.guided-after .formula{font-size:1.17rem}.guided-explanation{font-size:.92rem}.guided-actions{display:grid;grid-template-columns:1fr 1fr}.guided-actions .primary{grid-column:1/-1;margin:0}.guided-actions button{padding:10px 8px;font-size:.75rem}.guided-pieces{gap:8px}.guided-piece{padding:12px}.guided-piece strong{font-size:1.15rem}.branch-targets{grid-template-columns:1fr 18px 1fr;gap:5px}.branch-target{padding:12px 7px}.branch-target strong{font-size:.97rem}.split-groups{gap:10px}.split-groups>div{padding:15px 8px}.split-groups p{font-size:1.05rem}.reward button{margin-left:0}.reward-icon{font-size:1.7rem}.reward>div{flex:1;min-width:180px}#garden-dialog{padding:18px;width:calc(100% - 16px);max-height:calc(100dvh - 16px)}.garden-header{align-items:flex-start}.garden-header h2{font-size:1.3rem}.garden-header .secondary{padding:9px 10px;font-size:.75rem}.garden-plots{grid-template-columns:repeat(3,minmax(0,1fr))}.garden-plot{min-height:85px}.garden-plot>span{font-size:2.2rem}.garden-land{padding:55px 10px 14px}.garden-collection{grid-template-columns:repeat(3,minmax(0,1fr))}.collection-item strong{font-size:.67rem}.garden-summary{font-size:.74rem}.garden-open{font-size:.72rem;padding:9px 10px;gap:5px}.garden-open span{font-size:.6rem}.top-actions .save-label{max-width:170px;font-size:.55rem}.mirror-result{font-size:1rem}.guided-drop{font-size:.72rem}.mirror-controls{justify-content:flex-start}}
@media(prefers-reduced-motion:reduce){.branch-path,.line-journey,.line-destination,.guided-piece,.guided-after,.split-groups strong,.reward,.garden-plot.planted>span{animation:none!important}.reward-spark{display:none}}
@media print{#panel-guided,#garden-dialog,.top-actions{display:none!important}}

/* Unit ticks and individual arithmetic hops keep the number line readable. */
.number-line-caption{text-align:center;font-weight:700;margin:12px 0 0}.guided-line.precise-line{width:100%;max-width:660px;display:block;margin:0 auto}.precise-line text{font-size:14px}.unit-route{text-align:center;font-size:1.15rem;font-weight:800;color:var(--accent);margin:12px 0}.unit-jump{animation:unit-appear .4s both}@keyframes unit-appear{from{opacity:0}to{opacity:1}}@media(prefers-reduced-motion:reduce){.unit-jump{animation:none}}