/** define CSS variables */
:root{
--startup1: url("https://dl.dropboxusercontent.com/scl/fi/01fevw3r8b623rh8j6ebh/startButton1.png?rlkey=etgjy3s0ke3d5vczdmlghzpkq&dl");
--startup2: url("https://dl.dropboxusercontent.com/scl/fi/h28jp3j9zh0dzeqlux7mi/startButton2.png?rlkey=0gtktmnswuvv2ut8tfybz13an&dl");
--campaignButtonsImage: url("https://dl.dropboxusercontent.com/scl/fi/6esfv9z4bsvogn4td5oh8/game_info.png?rlkey=0i0tvpbvlsydyhpxkqa82514c&dl");
--detailsViewImage: url("https://dl.dropboxusercontent.com/scl/fi/xn4ljbou8z4b4olw2xwjq/details_background.png?rlkey=30oq4y256ioi0xd2o6xxtjufi&dl");
--laurels: url("https://dl.dropboxusercontent.com/scl/fi/k2dzp92wi94kq76gmoqox/laurels.png?rlkey=iauu6ifnulx1fl4tthsb0oi52&dl");
--mapMain: url("https://dl.dropboxusercontent.com/scl/fi/wy368tuycvzzlvxhk8sj8/map_main.png?rlkey=iupz9nsfv2uybcxn6j7ik7hjf&dl");
--mapLanes: url("https://dl.dropboxusercontent.com/scl/fi/j0hspt7ljm2nuk5d9m648/map_lanes.png?rlkey=5waah1m4vsyxbwhr8xtqwygs3&dl");
--mapGrid: url("https://dl.dropboxusercontent.com/scl/fi/wq86387jnw80f6czx4yom/map_grid.png?rlkey=sswekl54lro63a5xa6qohoxd9&dl");
--servo: url("https://dl.dropboxusercontent.com/scl/fi/cwtaunq5k3t3r8titt25w/servo.png?rlkey=uat9iefj1gmja50z4vign0vir&dl");
}