title: how to add css in page designer
body: <p>I have some page items, 3 IR regions and buttons in a form on apex5.0.
  How is it possible to write and attach a css files to make all these components, </p>
  
  <p>Page Item      : font-style: italic; font: Verdana
  Regions        : columns dark blue with grey background color for the header
  Data in regions: black font
  font-size      : medium
  Button         : Dark Grey with black font</p>
  
  <p>Is it possible to write a common css class or shall css class and attributes be added to each specific PI, Region &amp; button.
  How to do that?</p>