Compared to the article font-size of 15.2px editor text is too small to provide a convenient UX.
===== Steps to Reproduce:
Compare text in the editor to sidebar links, latter is the same as article text.
WTE / WTE2010:
1. https://www.mediawiki.org/w/index.php?title=2017_wikitext_editor&action=edit&useskin=timeless
WTE2017:
1. [[ https://www.mediawiki.org/wiki/Special:Preferences#mw-prefsection-betafeatures | Enable ]] "New wikitext mode"
1. https://www.mediawiki.org/wiki/2017_wikitext_editor?veaction=editsource&useskin=timeless
===== Reason
For historical reasons related to browsers implicitly setting monospace elements' font-size to something //around// 13px (inconsistently, ofc):
{T182320} sets the font-size to 13px for all skins, all editors, also when using non-monospace font.
Not an issue (not noticeable) in Vector (body: 14px), MonoBook (12.7px), Modern (13px).
Minerva avoids this by resetting paragraphs' (not the editor's) font-size to 16px.
===== Fix
Reset (inherit) default page font-size in editors (in Timeless).
== Screenshots
Bad vs Good:
| {F31621703} | {F31621704}
Before and after fix:
| {F31674547} | {F31674546}
== QA ==
Test on [[ https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Selenium_wikitext_editor_test_0.4671745916020327&action=edit | beta-cluster ]]:
WTE2010 source editor:
| mono | sans | serif
| [x] | [x] | [x] | `font-size:` 15.2px (with 16px browser setting)
| [x] | [x] | [x] | `font-family:` [[ https://gerrit.wikimedia.org/r/c/mediawiki/skins/Timeless/+/586426/1/resources/themes/wikimedia.less#35 | as defined ]]
WTE2017 VE source editor (NWE):
| mono | sans | serif
| [-] | [-] | [-] | `font-size:` 15.2px (with 16px browser setting)
| [-] | [-] | [-] | `font-family:` [[ https://gerrit.wikimedia.org/r/c/mediawiki/skins/Timeless/+/586426/1/resources/themes/wikimedia.less#35 | as defined ]]