Canonical orderthe unique non-ambiguous order defined by the formal grammar
Syntax
Formal syntax: <length> | normal
column-gap: 3px
column-gap: 2.5em
column-gap: normal
column-gap: inherit
Values
normal
Is a keyword indicating to use the browser-defined default spacing between columns. The specification, and most modern browsers follow it, recommends this keyword to be equal to a length of 1em.
<length>
Is a <length> value defining the size of the gap between columns. It must not be negative, but may be equal to 0.