Styles are not 1:1 between the editor and front-end

[richtabor]

Describe the bug
I created this pattern here, but have found that the front-end view of it is very different from what I've made. Is it possible to have consistent styling between the two? It looks like there's stuff missing on the front-end, as the pattern looks fine in the editor, but rough otherwise.

Expected behavior
The editor view of a pattern should be consistent with the front-end view that is rendered on the directory.

Screenshots

Editor:

End result:

[ryelle]

That editor screenshot is from wp-admin, but it's even more divergent in the frontend editor: