#board .cell{display:grid;place-items:center;min-width:0;padding:0;border-radius:0;background:white;color:#4338ca;border-right:1px solid #94a3b8;border-bottom:1px solid #94a3b8;font-size:clamp(18px,4.8vw,29px);font-weight:600;aspect-ratio:1;touch-action:manipulation}#board .cell.given{color:#19233d;font-weight:800;background:#f1f5f9}#board .cell.related{background:#eeecff}#board .cell.selected{background:#c7d2fe;box-shadow:inset 0 0 0 3px #4f46e5;z-index:1}#board .cell.error{color:#b91c1c;background:#fee2e2}#board .cell:nth-child(3n){border-right:2px solid #1e293b}#board .cell:nth-child(9n){border-right:0}#board .cell:nth-child(n+19):nth-child(-n+27),#board .cell:nth-child(n+46):nth-child(-n+54){border-bottom:2px solid #1e293b}#board .cell:nth-child(n+73){border-bottom:0}#board .pencil{display:grid;grid-template-columns:repeat(3,1fr);width:100%;height:100%;border:0;font-size:clamp(9px,2.2vw,13px);font-weight:500;color:#475569}#board .pencil small{display:grid;place-items:center;line-height:1}#number-pad{display:grid;grid-template-columns:repeat(9,1fr);gap:5px;max-width:510px;margin:0 auto 16px}#number-pad button{padding:10px 0;font-size:clamp(18px,4vw,25px);touch-action:manipulation}.game-actions{gap:8px}.game-actions button{padding:10px 12px;font-size:15px}#notes[aria-pressed=true]{background:#be185d;outline:3px solid #fbcfe8}button:disabled{opacity:.45;cursor:default}#play-puzzle{max-width:min(100%,520px);font-size:14px}#play-controls label{max-width:100%}#puzzleWrap{margin:16px 0}#board{height:auto;grid-template-rows:repeat(9,1fr)}@media(max-width:550px){.panel{padding:15px 10px;margin:10px}#board{width:min(87vw,510px)}.controls{gap:8px}.controls>button{font-size:14px}.controls select{max-width:100%}}

#game-help{margin:20px 0;background:#f0f4ff;border:1px solid #c7d2fe;border-radius:16px;overflow:hidden}#game-help summary{cursor:pointer;padding:15px 18px;font-weight:750;color:#4338ca;font-size:18px}#game-help summary:focus-visible{outline:3px solid #db2777;outline-offset:-4px}#help-content{padding:0 20px 18px;line-height:1.65}#help-content h3{font-size:18px;margin:18px 0 6px}#help-content p{margin:0;color:#334155;font-size:16px}