.container{
    height: 100vh;
    display: flex;
    justify-content:space-around ;
    align-items: center;
}
body{
    background-color: yellow;
}
#btnDecrease{
    height: 70px;
    width: 50px;
    font-size: 50px;

    background-color: red;

}
#btnIncrease{
    height: 70px;
    width: 50px;
    font-size: 50px;

    background-color: red;

}
h1{
    font-size: 50px;
}