:root{--ink:#253d36;--muted:#718077;--paper:#f7f6ef;--white:#fffefa;--line:#dcded3;--green:#244d40;--pale:#eaf0e4;--accent:#b06f4e;--radius:16px}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}button{border:1px solid var(--line);background:var(--white);color:var(--ink);border-radius:8px;padding:11px 15px;cursor:pointer;min-height:44px}button:hover{background:var(--pale);border-color:#9faa99}button:disabled{opacity:.45;cursor:not-allowed}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid var(--accent);outline-offset:3px}a{color:inherit;text-underline-offset:4px}h1,h2,h3,p{margin-top:0}h1{font:normal clamp(38px,4.6vw,66px)/1.06 Georgia,serif;letter-spacing:-2px;margin-bottom:18px}h2{font:normal 25px/1.2 Georgia,serif;letter-spacing:-.5px}label{display:block;font-size:12px;font-weight:650;margin:18px 0 7px}input,select,textarea{width:100%;border:1px solid var(--line);border-radius:7px;padding:11px;background:var(--white);color:var(--ink);min-width:0}textarea{font:17px/1.65 ui-monospace,monospace;resize:vertical}input[type=hidden]{display:none}select{min-height:46px}.site-header{max-width:1400px;margin:auto;padding:24px 48px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);gap:20px}.brand{font-size:25px;font-weight:700;letter-spacing:-1px;text-decoration:none;display:flex;align-items:center;gap:9px}.brandmark{font-size:32px;line-height:1}.brand-note{font-size:8px;letter-spacing:1.6px;font-weight:600;max-width:54px;border-left:1px solid #ccd1c4;padding-left:12px;margin-left:10px;line-height:1.5}nav{display:flex;gap:28px}nav a{text-decoration:none;font-size:13px;position:relative;padding:10px 0}nav a.active{font-weight:700}nav a.active:after{content:'';height:3px;background:var(--green);position:absolute;bottom:0;left:0;right:0}.private-label{font-family:Georgia,serif;font-style:italic;color:var(--muted)}main{max-width:1200px;margin:auto;padding:0 32px}.intro{display:flex;justify-content:space-between;align-items:center;padding:44px 0 36px}.eyebrow{font-size:10px;font-weight:700;letter-spacing:2px;color:var(--muted);margin-bottom:15px}.intro>div>p:last-child{font-size:15px;color:var(--muted);margin-bottom:0}.intro-note{border-left:1px solid var(--line);padding:8px 0 8px 30px;margin-right:15px}.intro-note span{font-size:9px;letter-spacing:1.6px;color:var(--accent)}.intro-note p{font:20px/1.5 Georgia,serif;margin:15px 0}.intro-note a{font-size:12px}.play-layout{display:grid;grid-template-columns:minmax(0,1.62fr) minmax(270px,1fr);gap:28px;align-items:start}.board-panel{padding:26px 34px 22px;background:var(--white);border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 9px 30px 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button{padding:6px 0;font-size:21px;border-color:#d9dfd1;background:#f5f7ee;min-width:0}.toolbar{display:flex;gap:7px;margin-top:16px}.toolbar button{flex:1;padding:8px;font-size:12px}kbd{font:9px monospace;color:var(--muted);margin-left:5px}.toolbar button[aria-pressed=true],.size-options button.active{background:var(--green);color:white;border-color:var(--green)}.keyboard-help{font-size:9px;color:var(--muted);text-align:center;margin:15px 0 0}.play-sidebar{display:grid;gap:17px}.card{border:1px solid var(--line);border-radius:var(--radius);padding:26px;background:var(--white)}.section-label{display:flex;justify-content:space-between;font-size:9px;font-weight:700;letter-spacing:1.6px}.section-label span{font-size:16px}.size-options{display:flex;gap:8px}.size-options button{flex:1;padding:8px}.seed-row{display:flex;gap:7px}.seed-row button{padding:6px 15px;font-size:22px}.primary{background:var(--green);color:white;border-color:var(--green)}.primary:hover{background:#315e4f;color:white}.wide{width:100%;margin-top:16px}.primary span{float:right}.fine{font-size:10px;line-height:1.6;color:var(--muted);margin:11px 0 0}.hint-card{background:#ecf0e5}.hint-card h2{margin:16px 0 10px}.hint-card p:not(.fine){font-size:13px;color:#5b6c60;line-height:1.7;margin-bottom:0}.secondary{background:transparent;border-color:#b4c3a7;font-size:12px}.progress-card{display:flex;gap:12px;padding:4px 8px;font-size:11px}.status-dot{width:7px;height:7px;border-radius:100%;background:#74916e;margin-top:6px}.progress-card p{margin:3px 0 0;color:var(--muted);font-size:10px}.text-button{border:0;background:none;font-size:11px;text-decoration:underline;text-underline-offset:3px;padding:6px;min-height:32px}.utility-row{display:flex;justify-content:space-between;gap:4px}.import-label{cursor:pointer;margin:0;font-weight:400}.import-label input{position:absolute;width:1px;height:1px;opacity:0}.bottom-strip{border-top:1px solid var(--line);margin:38px 0 30px;padding:26px 0;display:flex;justify-content:space-between;gap:20px;font-size:11px;color:var(--muted)}.bottom-strip b{display:block;color:var(--ink);font-size:13px;margin-bottom:4px}.bottom-strip a{align-self:center;color:var(--ink)}footer{max-width:1200px;margin:50px auto 0;padding:28px 32px;border-top:1px solid var(--line);display:flex;align-items:start;justify-content:space-between;gap:25px;font-size:10px;color:var(--muted)}footer .brand{font-size:19px;color:var(--ink)}footer details{max-width:380px}summary{cursor:pointer;font-size:12px;padding:12px 0}details p{font-size:12px}#proof{font-size:11px;max-height:200px;overflow:auto}.page-heading{padding:50px 0 30px;max-width:800px}.page-heading h1{font-size:48px}.page-heading>p:last-child{color:var(--muted)}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:26px;margin-bottom:40px}.two-col .card>label:first-child{margin-top:0}.button-row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.button-row button{font-size:12px}.soft{background:#edf0e6}.soft p,dd,.soft li{font-size:14px;line-height:1.8}.soft li{padding:10px}dt{font-weight:650;margin-top:22px}dd{margin:5px 0;color:#5f7167}.result{border-left:3px solid var(--accent);padding:12px 15px;margin:24px 0 15px;background:#f7f3e9;font-size:13px}.guide-nav{display:flex;gap:24px;margin-bottom:30px;font-size:12px;flex-wrap:wrap}.guide-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}.guide p{font-size:14px;line-height:1.85;color:#586d60}.guide h2{font-size:32px;margin:18px 0}.chapter{font-size:10px;letter-spacing:1.4px;color:var(--accent)}.guide a{font-size:12px}.practice-grid{max-width:380px;margin:22px 0}.practice-answers{margin-bottom:15px}.practice-answers button{font-size:20px;min-width:44px}.practice-grid .cell{font-size:26px}.print-paper{display:flex;flex-direction:column;align-items:center;background:#e9edde}.paper-illustration{width:240px;padding:22px 27px;background:white;box-shadow:4px 10px 16px #203e3120;transform:rotate(-3deg);margin:12px 0 30px}.paper-illustration p,.paper-illustration span{font-size:6px;letter-spacing:1px}.paper-grid{border:2px solid #31483d;font:32px/1.3 Georgia,serif;padding:10px;letter-spacing:10px;background:repeating-linear-gradient(0deg,transparent,transparent 40px,#ccc 41px,#ccc 42px),repeating-linear-gradient(90deg,transparent,transparent 40px,#ccc 41px,#ccc 42px);margin:20px 0}.print-paper>p{font-size:12px}.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);max-width:calc(100% - 24px);width:max-content;padding:12px 20px;background:var(--green);color:white;border-radius:10px;box-shadow:0 6px 30px #0002;z-index:12;font-size:13px}dialog{border:1px solid var(--line);border-radius:18px;padding:30px;max-width:460px;width:calc(100% - 32px);color:var(--ink);background:var(--white)}dialog::backdrop{background:#203b3355;backdrop-filter:blur(3px)}dialog p{font-size:14px}.skip{position:fixed;top:-60px;background:white;padding:12px;z-index:100}.skip:focus{top:10px}.print-sheet{background:white;margin:24px auto;padding:30px;max-width:700px;break-after:page}.print-sheet h2{font-size:24px}.print-sheet svg{width:100%;display:block}.print-sheet p{font-size:12px}#print-preview{margin:30px 0}[hidden]{display:none!important}
@media(min-width:1300px){.play-layout{grid-template-columns:minmax(0,1.6fr) minmax(320px,1fr)}.board-panel{padding:28px 45px}}@media(max-width:900px){.site-header{padding:20px 26px}.private-label{display:none}.play-layout{gap:18px;grid-template-columns:minmax(0,1.35fr) minmax(250px,1fr)}.board-panel{padding:22px}.card{padding:21px}.intro-note{margin:0;padding-left:20px}.intro-note p{font-size:18px}.toolbar{flex-wrap:wrap}.toolbar button{min-width:40%}}@media(max-width:700px){.site-header{padding:17px 18px;flex-wrap:wrap;gap:14px}.brand{font-size:23px}.brand-note{display:none}nav{width:100%;gap:0;justify-content:space-between}nav a{font-size:13px;padding:8px 5px}main{padding:0 18px}.intro{padding:28px 0 25px}.intro h1{font-size:46px}.intro>div>p:last-child{font-size:12px}.intro-note{display:none}.play-layout{grid-template-columns:1fr;gap:20px}.board-panel{padding:20px 16px}.cell{font-size:25px}.board-top{margin-bottom:20px}.board-meta{font-size:9px}.numpad{gap:4px}.numpad button{font-size:20px;min-height:44px}.toolbar{flex-wrap:nowrap;gap:4px}.toolbar button{min-width:0;font-size:11px;padding:7px 5px}kbd{display:none}.keyboard-help{font-size:8px}.play-sidebar{gap:16px}.card{padding:22px}.bottom-strip{flex-wrap:wrap;gap:20px;font-size:10px}.bottom-strip a{width:100%}.page-heading{padding:32px 0 20px}.page-heading h1{font-size:39px}.page-heading p{font-size:13px}.two-col,.guide-grid{grid-template-columns:1fr}.guide-nav{gap:16px}.guide h2{font-size:28px}.guide p{font-size:14px}.print-sheet{padding:12px}footer{margin-top:30px;padding:24px 18px;flex-wrap:wrap;gap:15px}footer p{margin:0}footer details{width:100%}.cell .cell-notes{font-size:9px}.paper-illustration{width:225px}.practice-grid .cell{font-size:26px}}@media(max-width:350px){main{padding:0 12px}.board-panel{padding:18px 10px}.intro h1{font-size:43px}.pill{font-size:8px;padding:5px 7px}.cell{font-size:21px}.numpad button{font-size:18px}.board-meta{font-size:8px}.cell .cell-notes{font-size:8px}.card{padding:19px}.site-header{padding:16px 12px}}
@media print{body{background:white}.site-header,footer,.page-heading,.two-col,.toast,#print-preview>.button-row,body main>.page:not(#print){display:none!important}main,#print{display:block!important;max-width:none;padding:0;margin:0}#print-preview{display:block!important;margin:0}#print-pages{display:block}.print-sheet{width:170mm;max-width:none;padding:0;margin:8mm auto;break-after:page}.print-sheet:last-child{break-after:auto}.print-sheet svg{width:170mm;height:170mm}.print-sheet h2{font-size:24pt}.print-sheet p{font-size:10pt}@page{size:A4;margin:12mm}}
.import-label{position:relative}.import-label input{width:1px;height:1px;padding:0;border:0;min-height:0;overflow:hidden;clip-path:inset(50%);left:0;top:0}