:root{font-family:Arial,Helvetica,sans-serif;color:#193c34;background:#f4f3ed;font-synthesis:none;--green:#143b32;--muted:#62716b;--lime:#d8ec8c;--line:#d8ddd4}*{box-sizing:border-box}body{margin:0}button,a,select,textarea{-webkit-tap-highlight-color:transparent}button{font:inherit;font-weight:700;border:1px solid var(--green);border-radius:7px;background:var(--green);color:#fff;padding:11px 17px;cursor:pointer}button:hover{background:#275b4d}button:focus-visible,a:focus-visible,select:focus-visible,textarea:focus-visible,#stage:focus-visible{outline:3px solid #dc941e;outline-offset:4px}button:disabled{opacity:.5;cursor:wait}.quiet{color:var(--green);background:transparent;border-color:var(--line)}.quiet:hover{background:#e6eade}.masthead{padding:20px 4%;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:30px;background:#fafbf6}.brand{display:flex;gap:12px;align-items:center;text-decoration:none;color:var(--green);font-size:15px;font-weight:800;letter-spacing:1.3px}.brand-icon{display:grid;place-items:center;position:relative;width:39px;height:39px;border-radius:9px;background:var(--green);color:var(--lime);font-size:29px;letter-spacing:-3px}.brand-icon span{position:absolute;right:3px;top:0;font-size:16px}.brand-sub{display:block;font-size:10px;letter-spacing:3px;margin-top:4px}.course-tag{font-size:10px;letter-spacing:1.6px;color:var(--muted);margin-left:auto}.course-tag span{margin:0 12px;color:#a5ada6}.masthead button{font-size:12px}main{max-width:1296px;margin:auto;padding:28px 36px 20px}.heading{display:flex;align-items:center;justify-content:space-between;gap:24px;margin-bottom:24px}.eyebrow{font-size:10px;font-weight:800;letter-spacing:2px;margin:0 0 10px}h1{font-size:clamp(24px,3.2vw,39px);letter-spacing:-1.3px;margin:0;font-weight:700}.intro{font-size:13px;line-height:1.65;color:var(--muted);margin:0}#practice{background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden;box-shadow:0 8px 30px #193c3407}.lesson-bar{display:flex;gap:25px;align-items:center;padding:15px 24px;border-bottom:1px solid #e6e9e0;background:#fafbf6}.step-label{font-size:12px;font-weight:700;min-width:70px}#progress{display:flex;list-style:none;margin:0;padding:0;gap:8px}#progress li{width:10px;height:10px;background:#dfe4d9;border-radius:50%;border:2px solid transparent}#progress li.done{background:var(--green)}#progress li.current{background:var(--lime);border-color:var(--green);box-shadow:0 0 0 3px #e9efdf}.practice-label{font-size:9px;letter-spacing:1.6px;color:var(--muted);margin-left:auto}.instruction{display:flex;gap:16px;align-items:center;padding:18px 24px;min-height:91px}#step-icon{font-size:16px;display:grid;place-items:center;background:#eff4e3;width:43px;height:43px;border-radius:10px;flex:none;color:#53743c;font-weight:700}h2{margin:0;font-size:20px;letter-spacing:-.4px}.instruction p{margin:6px 0 0;font-size:12px;color:var(--muted);line-height:1.4}.gesture{margin-left:auto;flex:none;font-size:9px;letter-spacing:1.1px;padding:7px 10px;border:1px solid var(--line);border-radius:5px}.frame{background:#202829;line-height:0}#stage{position:relative;width:100%;touch-action:none;user-select:none;cursor:crosshair}#screenshot{display:block;width:100%;height:auto;aspect-ratio:16/9;pointer-events:none;user-select:none}#overlay{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}.target{fill:#d8ec8c26;stroke:#82a52d;stroke-width:2;stroke-dasharray:6 4}.end-target{stroke:#1e9eba;fill:#1e9eba18}.hint-target{animation:pulse .7s ease-in-out infinite alternate;stroke:#eb9e13;fill:#ffcc4422;stroke-width:3}.selected{fill:#64a5ff33;stroke:#377ab6;stroke-width:1}.drag-preview{fill:#68bfdc22;stroke:#227c9d;stroke-width:2}.measure{fill:#bb5fee33;stroke:#a136da;stroke-width:2}.svg-label{font:700 12px Arial;fill:#143b32;paint-order:stroke;stroke:#fff;stroke-width:3}.feedback-bar{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:14px 24px;min-height:73px;font-size:12px}#feedback{line-height:1.5;max-width:650px}#feedback[data-kind=success]{color:#22653b;font-weight:700}#feedback[data-kind=retry]{color:#8c521a}.controls{display:flex;align-items:center;gap:10px;flex:none}.controls button{font-size:12px;padding:10px 14px}.controls span#attempts{color:var(--muted);font-size:10px;margin-right:5px}.controls #hint span{margin-left:10px}footer{display:flex;justify-content:space-between;gap:15px;color:#6b756e;font-size:10px;margin-top:20px;line-height:1.5}.status-dot{display:inline-block;width:6px;height:6px;background:#6d9278;border-radius:50%;margin-right:5px}.footer-divider{margin:0 10px}#complete{text-align:center;background:white;border:1px solid var(--line);border-radius:12px;padding:50px 25px}.complete-mark{display:grid;place-items:center;width:70px;height:70px;border-radius:50%;background:var(--lime);font-size:36px;margin:0 auto 23px}#complete h2{font-size:clamp(27px,4vw,42px);line-height:1.13;margin:14px 0 20px}#complete p:not(.eyebrow){font-size:14px;color:var(--muted);line-height:1.6}.summary{display:flex;justify-content:center;gap:50px;margin:32px 0}.summary strong{display:block;font-size:30px}.summary span{display:block;font-size:11px;color:var(--muted);margin-top:7px}.primary{background:var(--green);padding:14px 22px}.primary span{margin-left:20px}#debug{padding:20px;background:#f0eafb;color:#4a315e;font-size:12px;border-top:1px solid #d3c1e6}.debug-controls{display:flex;flex-wrap:wrap;gap:25px;margin:15px 0}#debug select{font:inherit;padding:6px}#rectangle{display:block;width:100%;max-width:650px;margin:10px 0;font:12px monospace;padding:10px}#debug button{font-size:12px}body:fullscreen{overflow:auto;background:#f4f3ed}[hidden]{display:none!important}@keyframes pulse{from{opacity:.5}to{opacity:1}}@media(prefers-reduced-motion:reduce){*{animation:none!important}}@media(max-width:850px){main{padding:20px 16px}.masthead{padding:14px 20px}.course-tag{display:none}.masthead button{margin-left:auto}.heading{margin-bottom:18px}.intro{font-size:11px}.instruction{padding:14px 16px}.lesson-bar{padding:13px 16px}.feedback-bar{padding:13px 16px;flex-wrap:wrap}.controls{margin-left:auto}h2{font-size:18px}.practice-label{display:none}}@media(max-width:560px){main{padding:18px 10px}.intro{display:none}h1{font-size:26px}.gesture{display:none}.instruction{gap:10px}#step-icon{width:32px;height:36px;font-size:13px}h2{font-size:16px}.controls{width:100%;justify-content:flex-end}#attempts{margin-right:auto}.summary{gap:20px}.summary span{font-size:10px}footer{flex-direction:column;gap:5px}.brand{font-size:12px}.brand-sub{font-size:8px}}
@media(min-width:700px) and (max-height:850px){.masthead{padding-top:10px;padding-bottom:10px}main{padding-top:16px}.heading{margin-bottom:16px}h1{font-size:30px}.instruction{padding-top:12px;padding-bottom:12px;min-height:75px}.frame #stage{max-width:calc((100svh - 390px) * 16 / 9);min-width:min(100%,640px);margin:auto}.feedback-bar{min-height:63px}footer{margin-top:12px}}

/* V2 arcade presentation. Animations never move the screenshot or pointer surface. */
:root{--green:#493194;--lime:#f7d36d;--muted:#605c76;--line:#dcd7eb;color:#292441;background:#f4f1fc;font-family:'Trebuchet MS','Arial Rounded MT Bold',system-ui,sans-serif}
body{background:radial-gradient(ellipse at 15% 0,#e9dff9,transparent 55%),radial-gradient(ellipse at 90% 85%,#dff4ef,transparent 60%),#f7f6fc}.masthead{background:#ffffffb8}.brand-icon{background:#493194;color:#ffe289}.brand{color:#382768}.course-tag{color:#605c76}.heading h1{font-size:24px;letter-spacing:-.5px}.heading .eyebrow{color:#785091}.intro{max-width:440px}.lesson-bar{background:#f9f7ff}.score-badge{margin-left:auto;font-size:14px;font-weight:900;color:#503091;background:#efe8ff;padding:7px 12px;border-radius:8px}.instruction{position:relative;display:block;text-align:center;padding:19px 54px 16px;min-height:106px}#instruction{font-family:'Trebuchet MS','Arial Rounded MT Bold',system-ui,sans-serif;font-weight:900;font-size:clamp(23px,2.8vw,37px);line-height:1.1;text-align:center;background:linear-gradient(90deg,#7630b2,#2856b8,#087c70,#9c5a08);background-clip:text;-webkit-background-clip:text;color:transparent;letter-spacing:-.8px}.instruction p{font-size:12px;line-height:1.4;margin-top:10px}#step-icon,.gesture{display:none}#progress li.done{background:#7154ad}#progress li.current{background:#f7d36d;border-color:#65429c;animation:dotPulse 1.8s ease-in-out infinite}.frame{position:relative}.feedback-bar{align-items:center;min-height:96px;background:#fff;padding:12px 22px}.feedback-stack{flex:1;min-width:0}.point-chip{display:inline-block;font-size:10px;font-weight:900;letter-spacing:.4px;padding:5px 9px;border-radius:20px;color:#176344;background:#e4f5df;margin-right:10px}.point-chip[data-eligible=false]{color:#7c4710;background:#fff0d7}#attempts{font-size:10px;color:#656076}#feedback{font-size:12px;margin-top:7px}#hint-text{font-size:12px;line-height:1.45;background:#f1eafd;color:#503377;border-left:3px solid #9871c7;padding:9px 12px;margin:9px 0 0}#hint small{display:block;font-size:9px;font-weight:400;margin-top:3px}.controls button{padding:9px 13px}.quiet:hover{background:#eee7fa}.complete-mark{background:#ffdf87;color:#775013}.score-caption{letter-spacing:4px;font-weight:900;margin:18px 0 0!important}#final-score{font-size:clamp(65px,10vw,112px);font-weight:900;letter-spacing:-5px;line-height:1.05;color:#543299;text-shadow:3px 4px 0 #eadff8}#complete h2{font-size:clamp(23px,3vw,34px);color:#38265f}#score-message{font-size:21px!important;font-weight:900;color:#356b59!important}#complete{position:relative;background:radial-gradient(ellipse at top,#fff3d4,transparent 55%),#fff;outline:none}#complete .summary{gap:35px;margin:22px 0 28px}#complete .summary strong{font-size:22px}.enter{animation:popIn 160ms ease-out}.nudge{animation:nudge 100ms ease-out}.success-glow{animation:glow 120ms ease-out}.celebrate{animation:celebrate 400ms ease-out}@keyframes popIn{from{opacity:.5;transform:scale(.97)}to{opacity:1;transform:scale(1)}}@keyframes nudge{0%,100%{transform:translateX(0)}35%{transform:translateX(-3px)}70%{transform:translateX(3px)}}@keyframes glow{50%{box-shadow:0 0 0 5px #d1ad47;filter:brightness(1.025)}}@keyframes dotPulse{50%{box-shadow:0 0 0 4px #efdeab}}@keyframes celebrate{from{opacity:.65;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}@media(min-width:700px) and (max-height:850px){.heading{margin-bottom:12px}.heading h1{font-size:23px}.instruction{padding:12px 24px;min-height:90px}#instruction{font-size:clamp(23px,2.6vw,34px)}.frame #stage{max-width:calc((100svh - 408px) * 16 / 9);min-width:min(100%,600px)}.feedback-bar{min-height:90px}.intro{font-size:11px}}@media(max-width:850px){.feedback-bar{gap:12px}.feedback-stack{min-width:260px}.masthead{gap:10px}.masthead #sound{margin-left:auto}.masthead #fullscreen{margin-left:0}.intro{max-width:300px}.summary{flex-wrap:wrap}}@media(max-width:560px){.instruction{padding:17px 12px}.score-badge{font-size:11px;padding:6px}.lesson-bar{gap:12px}#progress{gap:5px}#progress li{width:8px;height:8px}.masthead{padding:10px}.masthead button{padding:8px;font-size:10px}.brand-icon{width:30px;height:32px}.brand{gap:7px}#complete .summary{gap:22px}.intro{display:block;font-size:10px}.heading{display:block}.heading h1{font-size:22px}.intro{margin-top:9px}.feedback-stack{min-width:100%}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
/* V3: more progress markers and fields; retain the V2 title and feedback styling. */
#progress{flex-wrap:wrap;max-width:520px;row-gap:7px}#progress li{flex:none}.lesson-bar{gap:18px}#dimension-input{position:absolute;z-index:2;box-sizing:border-box;background:#fff;color:#242424;border:1px solid #619cc8;border-radius:0;padding:0 2px;font-family:Arial,sans-serif;line-height:1;text-align:right;touch-action:manipulation;user-select:text;min-width:0}#dimension-input:focus{outline:1px solid #4085b5;outline-offset:0}#dimension-input[aria-invalid=true]{border-color:#bd5839}#finale-image{display:block;width:min(100%,960px);height:auto;margin:20px auto;border:1px solid var(--line);border-radius:7px}#complete h2{font-family:'Trebuchet MS','Arial Rounded MT Bold',system-ui,sans-serif;background:linear-gradient(90deg,#7630b2,#2856b8,#087c70,#9c5a08);background-clip:text;-webkit-background-clip:text;color:transparent}#complete{padding-top:25px}.complete-mark{width:48px;height:48px;font-size:28px;margin-bottom:14px}@media(max-width:850px){#progress{max-width:280px;gap:6px}#progress li{width:8px;height:8px}.lesson-bar{gap:12px}}@media(max-width:560px){#progress{max-width:160px;gap:5px}#progress li{width:6px;height:6px}.lesson-bar{gap:8px}.step-label{min-width:65px;font-size:11px}}
@media(min-width:851px){#progress{max-width:560px}}