.game {
    width: 600px;
    height: 200px;
    border-bottom: 1px solid #000;
    margin: auto;
 }
 #dino {
    width: 50px;
    height: 50px;
    background-image: url(img/dino.png);
    block-size: 50px 50px;
    position: relative;
    top: 150px;
 }
 #cactus {
    width: 20px;
    height: 40px;
    background-image: url(img/png-clipart-game-off-game-jam-gamedev-net-video-game-cactus-game-angle.png);
    background-size: 20px 40px;
    position: relative;
    top: 110px;
    left: 580px;
    animation: cactusMov 1s infinite linear;
 }
 @keyframes cactusMov {
    0% {
        left: 580px;
    }
    100% {
        left: -20px;
    }
 }

 .jump {
    animation: jump 0.3s  linear;
 }
 @keyframes jump {
    0% {
        top: 150px;
    }
    30% {
        top: 130px;
    }
    50% {
        top: 80px;
    }
    80% {
        top: 130px;
    }
    100% {
        top: 150px;
    }
 }