The Box Model - The CSS - page 73

padding: 2em; /* shorthand: all sides */
padding: 2em 0; /* shorthand: top & bottom; right & left */
padding: 2em 0 1em; /* shorthand: top; right & left; bottom */
padding: 2em 0 1em 10px; /* shorthand: top; right; bottom;
left */
border-width
The border-width property sets the size of an element's border.
■ <length> : The border width will be a fixed dimension.
■ thin | medium | thick : The border width is designated by keywords
representing three border lengths of progressive thickness (not often
used because of the inconsistency in definition of actual dimensions).
The border-width property defines the width of the border on an
element. Like margin and padding , border-width is a shortcut for defin-
ing the four individual sides independently and can take one to four
values.
border-top-width: 2px;
border-right-width: 0;
border-bottom-width: 10px;
border-left-width: 1px;
border-width: 2px 0 10px 1px; /* shorthand: top; right;
bottom; left */
In Chapter 8, I discuss some of the visual options for borders in detail, but
only border-width impacts the dimensions of an element.