f7723559_CSS_HTML_XHTML_Reference_Book__Description_and_notes
[Property/Values] padding-top, padding-right, padding-bottom, padding-left either a length, percentage, or inherit [Description and notes] 
for specifying the distance between one side of an element's content area and its border initial value: 0; not inherited; percentages refer to width of containing block
CSS HTML XHTML Reference Book
Description and notes