Thickness Specification

A thickness attribute can contain a single value to represent a desired thickness in units. Alternatively, it can specify one or more specific thickness attributes:

• top
• left
• bottom
• right

For example, a border with a thickness of 5 units in all dimensions could be specified as border: 5, but could also be specified as border: { top: 5, left: 5, bottom: 5, right: 5 }. And of course, in the latter model, different values can be provided for each sub-attribute.