The Padding feature allows you to add padding between the contents of the widget and the edges of the widget's container (Fig 1). 


Fig 1


To illustrate, a dark blue border has been added to the Icon widget container and the square icon itself has been resized to the maximum size the container will accept (Fig 2). Please note that even though the Padding feature has been set to "0" for all four sides, there still exists some additional default padding around the Widget element and its container. 


Fig 2

Padding can be set equally for all sides (the default) or customized for the Top, Right, Bottom, and Left sides (Fig 3). 


Fig 3

The Style menu includes several features. For more information, read the relevant article: