Equal values on all four sides
If all four values (top, right, bottom, and left) are equal, then you simply write the following:
padding: 1px; border-width: 1px; margin: 1px;
The longhand way
If you don’t want equal values on all four sides, then you can specify each side individually:
padding-top: 1px; padding-right: 2px; padding-bottom: 3px; padding-left: 4px; border-top-width: 1px; border-right-width: 2px; border-bottom-width: 3px; border-left-width: 4px; margin-top: 1px; margin-right: 2px; margin-bottom: 3px; margin-left: 4px;
The shortcut (like clockwork)
However this seems to be quite a hassle typing out each property, so you’ll find it’s much easier to use the following shorthand, which is in this order: top, right, bottom, left (think of the hands going clockwise around a clock). The following is equivalent to the above code:
padding: 1px 2px 3px 4px; border-width: 1px 2px 3px 4px; margin: 1px 2px 3px 4px;
Other shorthands
This is the style I find myself writing in most often, but there are two other shorthand styles you should be aware of:
padding: 1px 2px 3px; /* top, left/right, bottom */ padding: 1px 2px; /* top/bottom, left/right */
Summary
In short, there are various ways to define the padding, border, and margin on an element. Here’s a recap, with padding used as an example:
padding: 1px; /* 1 value: top/right/bottom/left */ padding: 1px 2px; /* 2 values: top/bottom, left/right */ padding: 1px 2px 3px; /* 3 values: top, left/right, bottom */ padding: 1px 2px 3px 4px; /* 4 values: top, right, bottom, left */