*, *::before, *::after {
   box-sizing: border-box;
   user-select: none;
}

body {
   margin: 0;
   display: flex;
   justify-content: center;
   align-items: center;
   min-height: 100vh;
}

.world {
   overflow: hidden;
   position: relative;
   width: 100%;
   height: 200px;
}

.score {
   position: absolute;
   font-size: 3vmin;
   right: 1vmin;
   top: 1vmin;
}

.start-screen {
   position: absolute;
   font-size: 5vmin;
   top: 50%;
   left: 50%;
   transform: translate(-50%, -50%);
}

.hide {
   display: none;
}

.ground {
   --left: 0;
   position: absolute;
   width: 300%;
   bottom: 0;
   left: calc(var(--left) * 1%);
}

.dino {
   --bottom: 0;
   position: absolute;
   left: 1%;
   height: 30%;
   bottom: calc(var(--bottom) * 1%);
}

.cactus {
   position: absolute;
   left: calc(var(--left) * 1%);
   height: 30%;
   bottom: 0;
}