*{
    margin: 0;
    padding: 0;
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
}
body{
    background-color:aqua;
}
#wrapper{
    width: 750px;
    margin: 0 auto;
}
#header{
    text-align: center;
    margin: 20px auto;
}
#button_i {
    text-align: center;
    margin-bottom: 20px;
}
tr{
    margin: 5 5;
    background-color: aqua;
    width: 750px;
}