title: How to align button centered below table?
body: <p>I put form elements in a table so that column names and inputs are aligned to 2-columns.
  And I put submit button and cancel button below the table.
  The table width is not fixed.
  I want to put the buttons center-aligned of the table width.</p>
  
  <p>One simple way is to put the buttons in the table.
  But I want to separate them from the table.
  What's the most elegant way to do that?</p>