style.css

#canvas{
    border: 5px solid red;
    background : url("pictures/bg.png");
    animation: animatedBackground 20s linear infinite;
    background-repeat: repeat-y;
    margin-left: 75px;
}

@keyframes animatedBackground   {
			from { background-position: 0 0; }
			to { background-position: 0 1000px; }
		}
#player{
    display:none;
}
#alien{
    display: none;
}
#alien1{
    display: none;
}
#alien2{
    display: none;
}
#alien3{
    display: none;
}
#alien4{
    display: none;
}
#bullet{
    display: none; 
}
#blast{
    display: none; 
}

#play{
    position: absolute;
    right: 5px;
}
#pause{
    position: absolute;
    right: 5px;
}
#level{
    position: absolute;
    left: 2px;
}
#levelNo{
    position: absolute;
    left: 2px;
    top :30px
}
#score{
    position: absolute;
    left: 2px;
    top :70px
}
#score1{
    position: absolute;
    left: 2px;
    top :100px
}
#powerUp{
    display: none;
}
#powerUp1{
    display: none;
}
#final{
    text-align: center;
    padding:50px;
}
button{
    padding: 8px;
    padding-left: 20px;
    padding-right: 20px;
    padding-top: 8px;
    padding-bottom: 8px;
    font-size: 25px;
    border-radius: 6px;
    background-color:cornflowerblue;
    
}
button:hover{
    background-color: black;
    color: chocolate;

}