$tiled-gallery-gutter: 4px; // Fixed in JS, see `LayoutStyles` from `edit.jsx`
$tiled-gallery-selection: #0085ba; // Gutenberg primary theme color (https://github.com/WordPress/gutenberg/blob/6928e41c8afd7daa3a709afdda7eee48218473b7/bin/packages/post-css-config.js#L4)
