:root{color-scheme:light;--ink:#173c44;--muted:#5b7173;--sea:#176e73;--sand:#f6efe2;--line:#d9e0d8;--blue:#176dce;--red:#d73538;font-family:system-ui,-apple-system,"Microsoft JhengHei",sans-serif;background:var(--sand);color:var(--ink)}*{box-sizing:border-box}body{margin:0;background:radial-gradient(ellipse at 90% 5%,#dcefe7 0,transparent 45%),var(--sand)}button,input,summary{font:inherit}button,summary{touch-action:manipulation}button{cursor:pointer;border:1px solid var(--line);border-radius:12px;background:#fffdf8;color:var(--ink);min-height:44px;font-weight:650}button:hover:enabled{filter:brightness(.96)}button:focus-visible,summary:focus-visible,input:focus-visible,canvas:focus-visible{outline:3px solid #ce830d;outline-offset:3px}button:disabled{opacity:.45;cursor:default}[hidden]{display:none!important}main{max-width:1080px;margin:auto;padding:24px 24px 12px}.masthead{display:flex;align-items:center;justify-content:space-between;margin:0 0 24px;gap:12px}.brand{display:flex;align-items:center;gap:12px}.sun{font-size:42px;color:#c68928}.eyebrow{font-size:12px;letter-spacing:.09em;color:var(--muted);margin:0 0 4px}h1{font-size:28px;line-height:1.2;letter-spacing:-.03em;margin:0}h1 span{font-size:14px;letter-spacing:.05em;font-weight:500;margin-left:8px}.mode{border:1px solid #b7d0c5;border-radius:99px;padding:7px 12px;font-size:12px;white-space:nowrap}.game-layout{display:grid;grid-template-columns:minmax(260px,390px) minmax(280px,1fr);align-items:start;justify-content:center;gap:30px}.play-area{width:100%;max-width:min(390px,calc((100dvh - 255px)*var(--ratio,.5)));min-width:240px;justify-self:center}.hud{display:flex;justify-content:space-between;align-items:center;gap:8px;padding:0 2px 10px}.caption{display:block;font-size:11px;letter-spacing:.09em;color:var(--muted)}#score{display:block;font-size:30px;font-variant-numeric:tabular-nums;line-height:1.1}.hud-info{display:flex;flex-direction:column;align-items:flex-end;font-size:12px;gap:3px;flex:1}.hud-info #chain{color:var(--sea);font-weight:700}.small-button{padding:0 12px;min-height:40px}.board-wrap{position:relative;overflow:hidden;border:5px solid #245158;border-radius:16px;background:#193d45;box-shadow:0 12px 28px #1d49401c}#board{display:block;width:100%;height:auto;aspect-ratio:var(--ratio,.5);touch-action:pan-y}.overlay{position:absolute;inset:0;display:grid;place-items:center;padding:18px;background:#173c4466;backdrop-filter:blur(3px)}.overlay-card{width:100%;border-radius:16px;text-align:center;background:#fffaf0f5;padding:26px 14px;box-shadow:0 6px 24px #0002}.overlay-icon{font-size:38px;color:var(--sea)}h2{font-size:19px;margin:8px 0}.overlay-card p{font-size:13px;line-height:1.8;color:var(--muted);white-space:pre-line}.primary{background:var(--sea);border-color:var(--sea);color:white;padding:10px 30px}.controls{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;margin-top:12px}.controls button{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:59px;padding:3px}.controls button span{font-size:25px;line-height:1.1}.controls small{font-size:11px;margin-top:2px}.controls .drop{background:#d7e8df;border-color:#a8c5b7}.keyboard-hint{font-size:10px;text-align:center;color:var(--muted);margin:8px 0}.status{font-size:12px;line-height:1.5;min-height:36px;margin:8px 1px;color:var(--sea)}.sidebar{display:grid;gap:14px}.card{border:1px solid var(--line);border-radius:16px;background:#fffdf8;padding:18px}.next-card{display:flex;justify-content:space-between;align-items:center;min-height:100px}.next-card strong{font-size:24px}#next{width:108px;height:78px}.rules h2{margin:0 0 10px}.rules p,.rules li{font-size:13px;line-height:1.8}.rules ol{padding-left:20px;margin:12px 0}.subtle{font-size:12px!important;color:var(--muted);line-height:1.7}.options{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:6px 12px}.options label{display:flex;align-items:center;min-height:44px;gap:8px;font-size:13px}.options input{accent-color:var(--sea);width:19px;height:19px}.options p{width:100%;font-size:11px;margin:0;color:var(--muted)}.text-button{padding:0 12px;font-size:12px;background:transparent}.gallery summary{cursor:pointer;min-height:36px;font-weight:700}.gallery summary span{font-size:11px;color:var(--muted);font-weight:400;margin-left:8px}.pair-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.pair{border:1px solid #e4e7df;border-radius:10px;padding:9px 4px 6px;text-align:center;min-width:0;background:#f8f8f1}.pair canvas{display:block;width:116px;height:82px;max-width:100%;margin:0 auto}.pair strong{font-size:11px}footer{font-size:10px;color:var(--muted);text-align:center;margin:24px 0 8px}@media(min-width:900px){.sidebar{grid-template-columns:1fr}.gallery .pair-list{grid-template-columns:repeat(3,minmax(0,1fr))}}@media(max-width:620px){main{padding:12px 12px 8px}.masthead{margin-bottom:14px}.sun{font-size:31px}.brand{gap:7px}h1{font-size:22px}h1 span{display:none}.eyebrow{font-size:10px}.mode{font-size:10px;padding:6px 8px}.game-layout{display:flex;flex-direction:column;gap:14px;align-items:center}.play-area{max-width:min(100%,calc((100dvh - 240px)*var(--ratio,.5)));min-width:0;width:min(100%,390px)}.sidebar{width:100%;max-width:440px}.card{padding:15px}.next-card{min-height:80px}.keyboard-hint{font-size:9px}.overlay-card{padding:18px 8px}.overlay-card h2{font-size:18px}.overlay-card p{font-size:12px}.hud-info{font-size:10px}.controls{gap:5px}.controls button{min-height:50px}.status{margin-bottom:0}footer{margin-top:16px}}@media(max-height:540px) and (min-width:621px){main{padding-top:10px}.masthead{margin-bottom:10px}.play-area{max-width:240px}.game-layout{gap:20px}.overlay-card{padding:12px 8px}.overlay-card p{font-size:11px}.overlay-icon{display:none}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}

/* Keep the board and all controls visible on short desktops. */
@media(min-width:621px) and (max-height:740px){
  main{padding-top:10px}
  .masthead{margin-bottom:10px}
  .sun{font-size:28px}
  h1{font-size:23px}
  .play-area{width:calc((100dvh - 190px)*var(--ratio,.5) + 10px);min-width:191px;max-width:370px}
  .hud{padding-bottom:7px}
  #score{font-size:25px}
  .hud-info{font-size:10px}
  .controls{margin-top:8px;gap:5px}
  .controls button{min-height:44px}
  .controls button span{font-size:21px}
  .overlay-card{padding:12px 8px}
  .overlay-icon{display:none}
  .overlay-card h2{font-size:17px}
  .overlay-card p{font-size:11px}
}
@media(max-width:620px){.play-area{min-width:191px}}
@media(orientation:landscape) and (max-height:480px){
  .play-area{display:grid;grid-template-columns:minmax(0,1fr) 96px;gap:5px 10px;width:calc((100dvh - 146px)*var(--ratio,.5) + 116px);max-width:none;min-width:220px}
  .hud{grid-column:1/-1}
  .board-wrap{grid-column:1}
  .controls{grid-column:2;grid-row:2;align-self:end;grid-template-columns:repeat(2,1fr);margin:0}
  .controls button{min-height:54px}
  .keyboard-hint{display:none}
  .status{grid-column:1/-1}
  .masthead .eyebrow{display:none}
  .overlay-card{padding:8px 4px}
  .overlay-card p{font-size:10px;line-height:1.35}
  .overlay-card h2{font-size:13px}
  .overlay-card .primary{padding:6px;min-height:44px;font-size:12px}
}
#size-option{display:flex;flex-direction:column;gap:4px;margin:8px 0;font-size:12px}#board-size{font:inherit;min-height:44px;width:100%;border:1px solid var(--line);border-radius:8px;background:#fffdf8;color:var(--ink)}
@media(max-height:480px){.overlay{padding:4px}.overlay-icon{display:none}.overlay-card h2{margin:2px 0}.overlay-card p{margin:4px 0}.overlay-card #size-option{margin:4px 0}.overlay-card{padding:6px 4px}.overlay-card h2{font-size:12px}.overlay-card p{font-size:10px}}
@media(orientation:landscape) and (max-height:340px){.masthead{display:none}}