The column-gap CSS property sets the size of the gap between columns for elements which are specified to display as a multi-column element.

[Webplatform](docs.webplatform.org/wiki/css/properties/column-gap "Webplatform")
[Mozilla docs](https://developer.mozilla.org/en-US/docs/Web/CSS/column-gap "Mozilla")
[Caniuse](http://caniuse.com/#feat=multicolumn "Caniuse")