CKEditor (classic) video embed icon needs some styling

• Type: Bug
• Status: Verified
• Resolution: Unresolved
• Affects Version/s: Master
• Fix Version/s: None
• Component/s: CKEditor
• Labels: None
• Fix Priority: 2

Steps to reproduce

1. Make sure to use ckeditor_classic in the web content creation page, by setting the following property

editor.wysiwyg.portal-impl.portlet.ddm.text_html.ftl=ckeditor_classic

2. In some site, go to the web content creation page and create a "Basic Web Content"

Checkpoint: you should see the ckeditor classic, with a toolbar where a "Video" button is available right before "Source" mode button:

There are 2 visual glitches in this button.

 Observed:

1. Button has a different styling from the other ones: it's black rather than dark grey, it seems taken from a different button set
2. In "Source" mode, button is not greyed-out. This gives the impresion it's still clickable when it is not

 Expected:

1. Button has a similar style as the others, in particular, its color
2. In "Source" mode, button is greyed out

Video button seems to be the ootb one provided by ckeditor plugin. A quick check to the styling reveals that, as opposed to the other buttons in the bar, it's not being provided by editor.css