body{margin:0;overflow:hidden;font-family:sans-serif;background-color:#222;color:#fff}#gameCanvas{display:block;width:100vw;height:100vh}#uiOverlay{position:absolute;top:0;left:0;width:100%;height:100%;pointer-events:none;display:flex;flex-direction:column;justify-content:space-between;padding:15px;box-sizing:border-box}#uiOverlay>div{background-color:#00000080;padding:10px;border-radius:5px}#healthInfo{position:absolute;top:15px;left:15px}#gameInfo{position:absolute;top:15px;right:15px;text-align:right}#gameTitle{position:absolute;top:15px;left:50%;transform:translate(-50%);text-align:center;font-size:1.1em;font-weight:700}#upgradeSection{position:absolute;bottom:15px;left:15px}#upgradeSection button{pointer-events:all;padding:10px 15px;cursor:pointer}#messageOverlay{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);background-color:#000c;padding:30px;border-radius:10px;text-align:center;display:none;pointer-events:all}#messageOverlay.visible{display:block}#messageOverlay button{margin-top:15px;padding:10px 20px}#towerHealth,#playerHealth,#waveNumber,#score,#resources{font-weight:700}