Add classes to style a and button elements. input buttons are enhanced by the button widget. See this page for examples.
Note that in 1.4 data- attributes will still work. The deprecated buttonMarkup method will add the applicable classes to a and button.
Icon-only buttons are round by default. Here we show how you can set the same border-radius as other buttons.
Inline:
Theme B:
In 1.4 button will still be auto-enhanced. This example shows how you can prevent this.