object.style.gridColumnEnd = "value";
<'grid-column-end'> = <grid-line>
<grid-line> = auto | <custom-ident> | [ <integer> && <custom-ident>? ] | [ span && [ <integer> || <custom-ident> ] ]
auto
Automatically specified by the user agent.
<custom-ident>
Specifies any valid identifier that is not misinterpreted as a keyword.
<integer>
Specifies one or more decimal digits (0-9).
span
Specifies the number of tracks the item occupies.