style.css

html{
    box-sizing: border-box;
}
*, *::before, *::after{
    box-sizing: inherit;
}
body{
    background-color: #0a011a;
}
#ping-pong-table{
    border: 5px solid rgba(112, 101, 169, 0.429);
    width: 900px;
    height: 500px;
    position: relative;
    margin: auto;
    margin-top: 85px;
    /* background-color: #140e45; */
    background-color: #17104e;
}
h1{
    text-align: center;
    /* font-family:Arial, Helvetica, sans-serif ; */
    font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: 45px;
    color: #c0dcfad3;
}
#paddle{
    background-color: rgb(239, 95, 38);
    width: 20px;
    height: 90px;
    margin-left: 2px;
    position: absolute;
    border-radius: 20px;
   
}
#ball{
    background-color: rgb(255, 255, 255);
    width: 25px;
    height: 25px;
    border-radius: 50%;
    position: absolute;
}

#userscore, #aiscore{
    font-size: 50px;
    position: absolute;
    top: 12px;
    color: rgb(195, 199, 199);

}
#userscore{
    left:30%;
}
#aiscore{
    right: 30%;
}

.line{
    border-left: 2px dashed #554976;
    position: absolute;
    top: 0;
    left: 50%;
    width: 1px;
    height: 100%;
    transform: translate(-50%);
}
#aipaddle{
    background-color: rgb(7, 184, 84);
    width: 20px;
    height: 90px;
    margin-left: 2px;
    position: absolute;
    right: 2px;
     border-radius: 20px;
}