:root{color:#1f2522;background:#f6f4ef;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased}*{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh;background:linear-gradient(145deg,rgba(72,111,102,.16),transparent 34rem),linear-gradient(315deg,rgba(191,89,68,.14),transparent 30rem),#f6f4ef}body,button{-webkit-user-select:none;user-select:none}button{color:inherit;font:inherit;-webkit-tap-highlight-color:transparent}.app-shell{display:grid;grid-template-rows:auto auto auto auto;align-content:start;gap:.75rem;width:min(100%,46rem);min-height:100svh;margin:0 auto;padding:max(1rem,env(safe-area-inset-top)) 1rem max(1rem,env(safe-area-inset-bottom))}.topbar,.status-row{display:flex;align-items:center;justify-content:space-between;gap:1rem}.eyebrow{margin:0 0 .2rem;color:#68726d;font-size:.78rem;font-weight:700;letter-spacing:0;text-transform:uppercase}h1{margin:0;font-size:clamp(2rem,10vw,4rem);line-height:.95}.actions{display:flex;gap:.5rem}.icon-button{display:grid;place-items:center;width:2.75rem;height:2.75rem;border:1px solid rgba(31,37,34,.15);border-radius:8px;background:#ffffffbd;box-shadow:0 .7rem 1.6rem #1f252214;transition:background-color .14s ease,border-color .14s ease,box-shadow .14s ease,transform .14s ease}.icon-button svg{width:1.15rem;height:1.15rem}.icon-button:hover{border-color:#2c6a6380;background:#e9f1ec;box-shadow:0 .8rem 1.8rem #1f25221f}.icon-button:focus-visible{outline:3px solid rgba(191,89,68,.65);outline-offset:3px}.icon-button:active{transform:translateY(1px) scale(.97);border-color:#bf59448c;background:#f7d58f;box-shadow:0 .35rem .9rem #1f252224}.status-row{color:#4f5d57;font-size:.95rem;font-weight:700}.board-wrap{display:grid;justify-items:center}.board{display:grid;grid-template-columns:repeat(9,1fr);position:relative;width:min(100%,42rem);max-width:42rem;aspect-ratio:1;overflow:hidden;border:3px solid #202723;border-radius:8px;background:#202723;box-shadow:0 1.8rem 4rem #1f25222e}.board:after{position:absolute;inset:0;z-index:2;background:linear-gradient(to right,transparent calc(11.111% - .5px),rgba(31,37,34,.18) calc(11.111% - .5px),rgba(31,37,34,.18) calc(11.111% + .5px),transparent calc(11.111% + .5px)),linear-gradient(to right,transparent calc(22.222% - .5px),rgba(31,37,34,.18) calc(22.222% - .5px),rgba(31,37,34,.18) calc(22.222% + .5px),transparent calc(22.222% + .5px)),linear-gradient(to right,transparent calc(33.333% - 1.5px),#202723 calc(33.333% - 1.5px),#202723 calc(33.333% + 1.5px),transparent calc(33.333% + 1.5px)),linear-gradient(to right,transparent calc(44.444% - .5px),rgba(31,37,34,.18) calc(44.444% - .5px),rgba(31,37,34,.18) calc(44.444% + .5px),transparent calc(44.444% + .5px)),linear-gradient(to right,transparent calc(55.556% - .5px),rgba(31,37,34,.18) calc(55.556% - .5px),rgba(31,37,34,.18) calc(55.556% + .5px),transparent calc(55.556% + .5px)),linear-gradient(to right,transparent calc(66.667% - 1.5px),#202723 calc(66.667% - 1.5px),#202723 calc(66.667% + 1.5px),transparent calc(66.667% + 1.5px)),linear-gradient(to right,transparent calc(77.778% - .5px),rgba(31,37,34,.18) calc(77.778% - 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.5px),rgba(31,37,34,.18) calc(55.556% + .5px),transparent calc(55.556% + .5px)),linear-gradient(to bottom,transparent calc(66.667% - 1.5px),#202723 calc(66.667% - 1.5px),#202723 calc(66.667% + 1.5px),transparent calc(66.667% + 1.5px)),linear-gradient(to bottom,transparent calc(77.778% - .5px),rgba(31,37,34,.18) calc(77.778% - .5px),rgba(31,37,34,.18) calc(77.778% + .5px),transparent calc(77.778% + .5px)),linear-gradient(to bottom,transparent calc(88.889% - .5px),rgba(31,37,34,.18) calc(88.889% - .5px),rgba(31,37,34,.18) calc(88.889% + .5px),transparent calc(88.889% + .5px));content:"";pointer-events:none}.cell{display:grid;place-items:center;width:100%;aspect-ratio:1;border:0;outline:0;background:#fffdfa;color:#2c6a63;font-size:clamp(1.15rem,7vw,2.3rem);font-weight:800}.cell:focus,.cell:focus-visible{outline:0}.cell.given{color:#1f2522;background:#f1eee6}.cell.peer{background:#e9f1ec}.cell.same-value{background:#d7e9e2}.cell.selected{background:#f7d58f}.cell.conflict{color:#a43c34;background:#fae3dc}.digit-tray{display:grid;gap:.75rem;width:min(100%,42rem);justify-self:center;padding:1rem;border:1px solid rgba(31,37,34,.12);border-radius:8px;background:#ffffffdb;box-shadow:0 1rem 2rem #1f25221a}.tray-prompt{display:flex;align-items:center;min-height:2.75rem;margin:0;color:#4f5d57;font-weight:800}.digit-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.5rem}.digit-button,.clear-button{border:0;border-radius:8px;background:#244b46;color:#fff;font-weight:900}.digit-button{min-height:3.15rem;font-size:1.35rem}.clear-button{min-height:2.75rem;background:#e8e2d5;color:#29332f}.digit-button:disabled,.clear-button:disabled{cursor:not-allowed;opacity:.38}.difficulty-bar{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.4rem;width:min(100%,42rem);justify-self:center;padding:.35rem;border:1px solid rgba(31,37,34,.12);border-radius:8px;background:#ffffffa8}.difficulty-button{min-height:2.45rem;border:0;border-radius:6px;background:transparent;color:#4f5d57;font-weight:850;text-transform:capitalize;transition:background-color .14s ease,color .14s ease,transform .14s ease}.difficulty-button:hover{background:#e9f1ec;color:#244b46}.difficulty-button:focus-visible{outline:3px solid rgba(191,89,68,.65);outline-offset:2px}.difficulty-button:active{transform:scale(.98)}.difficulty-button.active{background:#244b46;color:#fff}@media(max-width:520px){.app-shell{gap:.75rem;padding-inline:.75rem}.digit-button{min-height:3.45rem}}@media(min-width:760px){.app-shell{padding-block:2rem}}