Text CAPTCHA placement for comments posting layout is not consistent anymore with text CAPTCHA from Registration and Login pages

STEPS TO REPRODUCE

1. Go to Administer Wiki > Other > CAPTCHA
2. Select Type > Text
3. Select one of the Engines (e.g. Simple Math)
4. Click 'Save' button
5. Go to Users & Rights > Rights
6. Tick "Require unregistered users to solve a CAPTCHA when posting a comment on a page"
7. Go to a page (or create one) and grant Comment rights for Unregistered users (from Page Administration)
8. Logout
9. Click inside comment field box to insert a comment (or click 'Comment' button in newer XWiki versions)

EXPECTED RESULTS

The CAPTCHA content is vertically centered between comment input field box and the 'Answer' input box and the 'Reload' link is placed in the right side of it, in the same line (see Text_CAPTCHA_Centered_XWiki_11_10.png).

ACTUAL RESULTS

The CAPTCHA content is placed near the top comment input field box, a large white space being displayed below it and 'Reload' button which is placed at the bottom right (see Text_CAPTCHA_large_space_13_9.png).

The issue doesn't reproduce for text CAPTCHA displayed in Registration page or for CAPTCHA displayed on Login page for failed authentications.

Reproduced on XWiki 11.10.1 (also on 12.10.10, 13.4.5 and 13.9), but it doesn't reproduce in XWiki 11.10.