html,body{background-color:#1a202c;width:100%;height:100%;margin:0;padding:0;overflow:hidden}*{box-sizing:border-box}.app-container{box-sizing:border-box;background-color:#1a202c;background-image:linear-gradient(#3182ce26 1px,#0000 1px),linear-gradient(90deg,#3182ce26 1px,#0000 1px);background-position:50%;background-size:20px 20px;justify-content:center;align-items:center;width:100vw;height:100vh;min-height:100vh;margin:0;padding:10px;display:flex;overflow:hidden}.game-wrapper{box-sizing:border-box;flex-direction:column;justify-content:center;align-items:center;width:100%;max-width:95vw;height:98vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Inter,Arial,sans-serif;display:flex}.game-wrapper h2{color:#fff;text-shadow:0 2px 4px #00000080;text-align:center;margin:0 0 8px;font-size:clamp(1.1rem,3vw,1.8rem)}.controls-container{flex-wrap:wrap;justify-content:center;gap:4px;margin-bottom:8px;display:flex}.difficulty-btn{cursor:pointer;color:#2d3748;background-color:#fff;border:1px solid #cbd5e0;border-radius:4px;padding:4px 8px;font-size:clamp(.65rem,1.8vw,.8rem)}.difficulty-btn.active{color:#fff;background-color:#3182ce;font-weight:700}.hud-container{grid-template-columns:repeat(4,minmax(60px,90px));justify-content:center;gap:6px;width:100%;margin-bottom:8px;font-size:clamp(.7rem,1.5vw,.8rem);display:grid}.hud-box{text-align:center;background:#edf2f7;border-radius:6px;padding:4px}.hud-box.urgent,.hud-box.warning{color:#fff;background-color:#e53e3e;font-weight:700}.hud-box.high-score{background:#f6e05e;font-weight:500}.game-grid{box-sizing:border-box;--cell-w:calc((85vw - (var(--grid-cols) * 6px)) / var(--grid-cols));--cell-h:calc((58vh - (var(--grid-rows) * 6px)) / var(--grid-rows));--final-size:min(var(--cell-w), var(--cell-h));grid-template-columns:repeat(var(--grid-cols), var(--final-size));place-content:center;gap:6px;display:grid}.card-container{width:var(--final-size);height:var(--final-size);perspective:1000px;cursor:pointer}.card-inner{text-align:center;width:100%;height:100%;transform-style:preserve-3d;transition:transform .4s cubic-bezier(.4,0,.2,1);position:relative}.card-container.is-flipped .card-inner{transform:rotateY(180deg)}.card-front,.card-back{backface-visibility:hidden;box-sizing:border-box;width:100%;height:100%;font-size:calc(var(--final-size) * .5);border-radius:6px;justify-content:center;align-items:center;display:flex;position:absolute;box-shadow:0 2px 4px #0003}.card-front{background-color:#edf2f7;border:1.5px solid #cbd5e0;transform:rotateY(180deg)}.card-back{background-color:#2d3748;background-image:linear-gradient(#ffffff0d 1px,#0000 1px),linear-gradient(90deg,#ffffff0d 1px,#0000 1px);background-size:25% 25%;border:1.5px solid #1a202c}.modal-overlay{z-index:15;background:#000000d9;justify-content:center;align-items:center;width:100%;height:100%;padding:20px;display:flex;position:fixed;top:0;left:0}.modal-content{text-align:center;background:#fff;border-radius:12px;width:100%;max-width:350px;padding:24px}.play-again-btn{color:#fff;cursor:pointer;background-color:#3182ce;border:none;border-radius:6px;width:100%;margin-top:12px;padding:8px 16px;font-size:1rem;font-weight:700}