.birthday.cube
{
    background-color:rgba(255, 255, 255, 0.5);
    border:solid 4px rgba(255, 255, 255, 0.8);
    float:right;
    width:calc(100% - 60px);
    margin:0 30px;
    padding:40px;
    border-radius:30px;
    margin-top:80px;
}