index.css

html,body,.game{
    padding : 0;
    margin : 0;
    border: none;
    width:590px;
    height:820px;
    position: fixed;
    top:0;
    left:0;
    overflow: hidden;
    background:lightblue !important;
}

*:not(input){
    user-select: none;
    -webkit-user-select:none;
}

html{
    background: black;
}

.bird{
    height :50px;
    width:50px;
    background:yellow;
    position: absolute;
    transition: all 0.1s ease;
}
.button{
    height:100px;
    width:100px;
    position: absolute;
    left:calc(50% - 50px);
    bottom:0;
    background: red;
}

.tuyau{
    position: absolute;
    top:calc(50% - 900px);
    margin:0px;
    background:blue;
    transition: all 0.1s ease;
    height:200px;

}

.tuyau::after{
    content:' ';
    display: block;
    height: 1000px;
    background:green;
    width:50px;
    position: relative;
    top:100px;
}

.tuyau::before{
    content:' ';
    display: block;
    height: 1000px;
    background:green;
    width:50px;
    position: relative;
    bottom:100px;
}

h1.score{
    position: absolute;
    top:0;
    left:0;
    margin:20px;

}