Regarding your CSS for your Template:Tab_content in MediaWiki:Common.css
Take a look at Okina's page: notice how there is a unnecessary empty line between the image and the caption in the infobox? This is because your
.tab_content_container class doesn't have
display: inline-block; as part of its CSS rules. Adding this rule via the style-parameter of your template fixes the issue (as seen in this example).
As you can see on the list of pages which use your template, currently only five regular pages make use of your template (all of them for the purpose of displaying multiple images inside a Character Infobox).
This means I could
- edit those pages to include
display: inline-block;as part of the style-parameter of your template (not futureproof, unneeded duplication)
- include the CSS in the template, either inline or via TemplateStyles (inline is hard to read; TemplateStyles is better)
- wait for you to update your CSS in MediaWiki:Common.css (since I don't have the rights to edit that page, obviously)
If I don't hear from you in 14 days (just reply below this post), I'm just going to go ahead with the TemplateStyles option.