html center positioning of two divs

Is there a better way to positioning the to tables in the middle?

Code: http://ift.tt/1HnLY3z

#layout {
  display: table;
  margin: 40px auto;
}

#tetrisfield, #nextstone {
  border-collapse: separate;
  border: 10px solid gray;
}

#nextstone {
    margin-bottom: 150px;
}

html,body {
  margin: 0px;
  height: 100%;
  color: white;
  background-color: black;
  text-align: center;
}

#tetrisfield td, #nextstone td {
    width: 23px;
    height: 23px;
    background-color: rgba(255, 255, 255, 0.1);
}

Currently I insert the tables in another centered table. My problem is - if I work with position relative or absolute and want to resize the window, the tables overlaped.