:root{--ink:#243f3b;--muted:#536962;--paper:#fffdf7;--teal:#286d5f;--line:#dce5dc;--orange:#efb15e}
*{box-sizing:border-box}body{margin:0;color:var(--ink);background:#f5f3e9;font-family:system-ui,-apple-system,"Noto Sans JP",sans-serif;line-height:1.65}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{min-height:46px;padding:10px 15px;border:1px solid #a9b9ad;border-radius:12px;background:var(--paper);color:var(--ink);cursor:pointer;font-weight:650}button:hover:not(:disabled){background:#e8f0e6}button:disabled{opacity:.45;cursor:default}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #ba4a24;outline-offset:4px}a{color:#245f53}h1,h2,h3,p{margin-top:0}h1{font-size:clamp(2rem,4.5vw,3.6rem);line-height:1.4;letter-spacing:.035em;margin:18px 0}h2{font-size:clamp(1.3rem,2.5vw,1.7rem);line-height:1.6;margin-bottom:4px}rt{font-size:.4em}small{display:block;font-weight:400}main{max-width:1160px;margin:auto;padding:32px 26px}footer{border-top:1px solid var(--line);margin-top:32px;padding:18px 0;display:flex;flex-wrap:wrap;gap:10px 22px;color:var(--muted);font-size:.8rem}[hidden]{display:none!important}.eyebrow{font-size:.85rem;letter-spacing:.13em;font-weight:750;color:var(--teal)}.home{display:grid;grid-template-columns:1fr 1fr;gap:18px 30px;padding-top:30px}.lead{font-size:1.5rem;font-weight:650;line-height:1.8}.intro>p:last-child{color:var(--muted)}.hero-art{align-self:center;background:#efe9d6;border-radius:50% 50% 20% 40%;text-align:center;padding:14px 12px 24px}.hero-art svg{width:100%;max-height:300px}.hero-art svg text{font-size:27px;fill:var(--ink)}.hero-art span{font-size:.8rem;letter-spacing:.06em}.mode-cards{grid-column:1/-1;display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:26px}.mode-card{display:flex;text-align:left;align-items:center;gap:18px;padding:24px;border:1px solid #c7d5c8;border-radius:18px;box-shadow:0 5px 0 #dde4d8}.mode-card strong{font-size:1.18rem}.mode-card small{margin-top:6px;color:var(--muted)}.mode-card .number{font-size:1.6rem;font-family:Georgia,serif;color:var(--teal)}.mode-card>span:last-child{margin-left:auto}.mode-card.accent{background:#e1eee3}.home>p,.home>#connection-retry{grid-column:1/-1;margin:0;font-size:.9rem}.section-top{display:flex;align-items:center;gap:20px;flex-wrap:wrap;margin-bottom:22px}.section-top>button{background:transparent;border:none;padding-left:0}.section-top>#counter{margin-left:auto;font-weight:700}.workspace{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(290px,1fr);gap:22px;align-items:start}.workbench{background:var(--paper);border:1px solid var(--line);border-radius:22px;overflow:hidden}.question-bar{padding:22px 24px 4px}.question-bar p{font-size:.9rem;color:var(--muted);margin:4px 0 0}.viewer{height:400px;position:relative;background-image:radial-gradient(#b8caba 1px,transparent 1px);background-size:22px 22px}.viewer canvas{display:block;width:100%;height:100%;touch-action:none}.bench-caption{display:flex;justify-content:space-between;flex-wrap:wrap;padding:12px 20px;font-size:.75rem;color:var(--muted);gap:6px;border-top:1px solid var(--line)}.tools{display:grid;gap:15px;min-width:0}.tools fieldset{margin:0;padding:0;border:0}.tools legend,.tools label{font-size:.85rem;font-weight:650}.face-buttons{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.face-buttons button{min-height:65px;padding:6px 4px;border:2px solid transparent}.face-buttons button strong{display:block;font-size:1.6rem;line-height:1.3}.face-buttons button small{font-size:.68rem}.face-buttons button[aria-pressed=true]{border-color:#203e3a;box-shadow:inset 0 0 0 3px white}.face-buttons button.base{border:2px solid #273c42;opacity:1}.face-buttons button.selected{border:3px dashed #273c42}.face-buttons button.correct{box-shadow:inset 0 0 0 3px white;border:3px double #273c42}.button-row{display:flex;flex-wrap:wrap;gap:8px}.button-row>button{flex:1;white-space:nowrap}.primary{color:white;background:var(--teal);border-color:var(--teal)}button.primary:hover:not(:disabled){background:#1b5549}.scrubber{display:flex;align-items:center;gap:12px;margin-top:10px}.scrubber input{width:100%;min-width:0;accent-color:var(--teal);min-height:35px}.rotation{display:flex;gap:6px}.rotation>button{flex:1;min-width:0;padding:8px 4px}.rotation>#reset{flex:2.8;font-size:.85rem}.ghost-label{padding:10px;background:#e8eee5;border-radius:10px;display:flex;align-items:center;gap:7px}.ghost-label input{width:20px;height:20px;accent-color:var(--teal)}#feedback:empty{display:none}#feedback{padding:14px 16px;border-radius:14px;background:#e4efe3;border-left:4px solid var(--teal);font-weight:650}#feedback.wrong{background:#fcf0df;border-color:#c07c35}#net-picker{display:flex;align-items:center;gap:12px}select{min-width:0;max-width:100%;padding:10px;border:1px solid #abbab0;border-radius:10px;background:var(--paper);color:var(--ink)}.pair{border:1px dashed var(--teal);border-radius:14px;padding:12px;text-align:center;font-size:1.3rem;letter-spacing:.1em}.pair small{font-size:.75rem;letter-spacing:0}.next{width:100%}.failure{padding:20px;background:#fff0df}.results{max-width:660px;margin:20px auto;background:var(--paper);padding:30px;border:1px solid var(--line);border-radius:24px}.results h2{font-size:2.2rem;margin:15px 0}.results ol{list-style:none;padding:0;margin:24px 0}.results li{display:flex;align-items:center;gap:14px;padding:14px 0;border-top:1px solid var(--line)}.results li span{flex:1}.results li small{font-size:.8rem}.results li button{font-size:.85rem}#save-panel,#identity-panel{margin-top:20px;padding:16px;border:1px solid #bfcfbd;border-radius:12px;background:#fffdf7}#save-panel p{margin-bottom:8px}#save-panel a{margin-left:12px}.celebrate{animation:stamp .45s ease-out}@keyframes stamp{0%{transform:scale(.97)}60%{transform:scale(1.02)}100%{transform:scale(1)}}
@media(max-width:800px){main{padding:18px 16px}.workspace{grid-template-columns:1fr}.viewer{height:340px}.tools{gap:13px}.face-buttons{grid-template-columns:repeat(6,1fr)}.face-buttons button{min-height:58px}.home{padding-top:12px;gap:12px}.mode-cards{gap:12px}.mode-card{padding:18px 14px;gap:10px}.mode-card strong{font-size:1rem}.mode-card small{font-size:.75rem}.lead{font-size:1.2rem}.section-top{gap:10px;margin-bottom:12px}.question-bar{padding:15px 16px 0}}
@media(max-width:520px){.home{grid-template-columns:1fr}.hero-art{max-width:300px;justify-self:center;padding:0 8px 18px}.hero-art svg{max-height:195px}.intro{text-align:center}.intro>p:last-child{display:none}.mode-cards{grid-template-columns:1fr;margin-top:10px}.mode-card{padding:18px}.mode-card strong{font-size:1.05rem}.viewer{height:290px}.face-buttons{grid-template-columns:repeat(3,1fr)}.face-buttons button{min-height:60px}.section-top .eyebrow{font-size:.72rem;letter-spacing:0}.section-top button{font-size:.8rem}.question-bar h2{font-size:1.25rem}.results{padding:22px 16px}.results li{gap:8px}.results li button{padding:8px}.bench-caption{padding:10px 12px;font-size:.7rem}footer{font-size:.72rem}.lead{margin-bottom:8px}}
.scrubber{white-space:nowrap}.scrubber input{flex:1;width:0}.home>#last-result{grid-column:1/-1;justify-self:start}.face-buttons button:disabled{opacity:1;cursor:default}
.question-bar .success-banner{margin:12px 0;padding:12px 8px;border:2px solid var(--teal);border-radius:14px;background:#e4efe3;color:var(--teal);font-size:clamp(1.8rem,5vw,2.5rem);font-weight:800;line-height:1.4;text-align:center}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
.completion-card{grid-column:1/-1;background:#fff0d8}.placement-board{display:grid;grid-template-columns:repeat(var(--columns),minmax(0,1fr));grid-template-rows:repeat(var(--rows),1fr);gap:4px;width:min(100%,310px);aspect-ratio:var(--columns)/var(--rows);margin:16px auto}.placement-board>*{min-width:0;min-height:0;aspect-ratio:1;display:flex;flex-direction:column;align-items:center;justify-content:center;border-radius:8px;line-height:1.1}.placement-board .fixed-face{font-size:1.6rem;border:2px solid white}.placement-board .placement{padding:2px;border:2px dashed #658079;background:#fffdf7;font-size:1.1rem;touch-action:manipulation}.placement-board .placement:disabled{opacity:1}.placement-board .placed{background:#aad086;border:3px solid #263d38}.placement-board .example{border:4px double #286d5f;background:#dcf0e0}.placement-board .wrong-place{border:3px dashed #a63c28;background:#fce0d4}.placement-board small{font-size:.65rem;margin-top:2px}#placement-panel{padding:4px 12px 12px}#placement-notice{font-size:.85rem;text-align:center;margin:8px 0}.model-source{margin:12px 16px;padding:10px;border-left:4px solid var(--teal);background:#edf2e7;font-weight:700;font-size:.9rem}#completion-actions{display:grid;gap:8px}#result-mode{font-weight:700;color:var(--teal);margin:8px 0}.model-source.correction-source{background:#fff0df;border-color:#b77133}

/* Keep the next action in reach while leaving explanations and observations scrollable. */
@media(max-width:700px),(max-height:500px) and (max-width:1000px){
  #workshop:has(#next:not([hidden])){padding-bottom:calc(84px + env(safe-area-inset-bottom,0px))}
  #workshop :is(#next:not([hidden])){position:fixed;z-index:20;left:max(12px,env(safe-area-inset-left,0px));right:max(12px,env(safe-area-inset-right,0px));bottom:calc(10px + env(safe-area-inset-bottom,0px));width:auto;margin:0;min-height:52px;box-shadow:0 0 0 6px #fffdf7,0 -4px 18px #073e7d24}
}

#net-picker{display:block}