.shot{
    position: absolute;
    width: 15px;
    height: 10px;
    background: springgreen;
    border-radius: 50%;
    transition: ease-in-out;
    
}
.bullet{
    position: absolute;
    width: 15px;
    height: 10px;
    background-color: blue;
    border-radius: 50%;
    transition: ease-in-out;
    
}

.enemy {
    position: absolute;
    width: 30px;
    height: 30px;
    background: red;
    border-radius: 50%;
}
.player {
    position: absolute;
    width: 20px;
    height: 20px;
    background: skyblue;
    border-radius: 50%;
    
}
body,html{
    margin: 0;
    position: relative;
    overflow: hidden;
    background-color: gray;
}
#system{
    width: 100vw;
    height: 100vh;
}