Hello @amilica , all,
The first question I have that we probably should look at when looking at corner rounding is:
should the radius be a fixed size or a proportion of the size of the element whose borders are round?
My view on it:
- if the objective is to obtain circles like google search input, then it needs to be a proportion
- if the objective is to soften a sharp edge, then it can be a fixed size.
Design system’s view on it:
Bootstrap 3 (the one we use) actually has 3 radius sizes:
- a base
- a small one
- a large one
and I imagine it may use a different radius size depending on the element.
See Customize and download · Bootstrap (these are awfully hardcoded in pixels in bootstrap 3 but well, then again, everything is hardcoded in bootstrap 3 
).
From my point of view, the choice we make here should be implementable uniquely by adjusting the defaults of these variables of bootstrap, which has the great benefit of allowing whoever customizes a color theme for XWiki to set them all to other values to obtain a different look (e.g. I set them often all to 0 these days ).
Thus, in order to see how an adjustment of corners would look on the various elements of XWiki, I think we’d need to check which elements use which size of radius from bootstrap, as their look may adjust differently (and not be 7px everywhere). For example, I can expect that a well (the warning) has a large radius while a button has a base radius (but I don’t know exactly, it needs to be checked).
Thanks,
Anca