title: How do you make buttons of the python library "urwid" look pretty?
body: <p>The default appearance of a button in urwid is very functional, but in my eyes not very pretty.
  It can also be irritating when several buttons are side by side in a row.</p>
  
  <p>How can I achieve that a button is displayed with a frame and centered text and changes its color when it gets the focus?</p>
  
  <p><a href="https://i.stack.imgur.com/DIC8P.png" rel="noreferrer"><img src="https://i.stack.imgur.com/DIC8P.png" alt="enter image description here"></a></p>