html {
            overflow: hidden;
            height: 100%;
            background: #191919;
            width: 100%;
        }
        
        #canvas {
            background: url('https://marclopezavila.github.io/planet-defense-game/img/space.jpg') no-repeat;
            width: 100%;
            height: 100%;
            background-size: cover;
        }
        
        #canvas.playing {
            cursor: url('https://marclopezavila.github.io/planet-defense-game/img/aim_red.png') 17.5 17.5,auto !important;
        }