.app-shell{display:grid;gap:1.4rem;min-height:100vh;max-width:1160px;margin:0 auto;padding:1.2rem 1.25rem 1.8rem;position:relative}.top-bar{display:grid;grid-template-columns:auto minmax(120px,1fr) auto;gap:1rem;align-items:center;padding-bottom:.55rem;border-bottom:1px solid rgba(43,53,69,.15)}.difficulty-tabs{display:flex;flex-wrap:wrap;gap:.25rem 1rem;justify-self:start;grid-column:1}.top-actions{display:flex;gap:1rem;align-items:center;justify-self:end;grid-column:3}.top-center{display:flex;align-items:center;gap:.55rem;justify-items:center;grid-column:2}.game-layout{display:grid;grid-template-columns:minmax(280px,684px) minmax(250px,360px);gap:1.4rem;align-items:start;justify-content:space-between}.sudoku-board{width:min(100%,684px);max-width:684px;aspect-ratio:1 / 1;display:grid;grid-template-columns:repeat(9,1fr);grid-template-rows:repeat(9,1fr);border:2px solid;border-radius:12px;overflow:hidden;position:relative}.cell{display:grid;place-items:center;border-right:none;border-bottom:none;background:transparent;border-left:none;border-top:none;padding:0}.thick-right{border-right:2px solid}.thick-bottom{border-bottom:2px solid}.side-panel{display:grid;gap:1rem;width:min(100%,360px)}.mode-box{display:flex;justify-content:space-between;gap:.5rem;padding:1rem 1.1rem;border:2px solid;border-radius:12px}.number-panel{border:2px solid;border-radius:12px;padding:.75rem}.number-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.5rem}.tool-row{display:grid;grid-template-columns:repeat(3,1fr);gap:.75rem}.prompt-shortcut{justify-self:end;margin-top:.25rem}.win-overlay{position:fixed;top:0;right:0;bottom:0;left:0;display:grid;place-items:center;padding:1rem;pointer-events:none;z-index:9999}.win-card{width:min(520px,95vw)}@media(max-width:1120px){.game-layout{grid-template-columns:1fr;justify-content:start}.side-panel{max-width:520px}}@media(max-width:700px){.app-shell{gap:1.25rem;padding:1rem 1rem 1.5rem}.top-bar{grid-template-columns:1fr;justify-items:start}.difficulty-tabs,.top-actions{grid-column:1}.top-actions{width:100%;justify-self:stretch}.top-center{width:100%;justify-items:start;grid-column:1;flex-wrap:wrap}.action{flex:1}}