Extra space next to centred tagline when floated

[laurelfulford]

Moved from #1594

Ran into a weird style with Center Logo on (step 10) on non-simplified headers. With a site description, at the breakpoint between 780px and 980px, the site description ends up floating weirdly below and to the right of the logo:

I would expect the behavior at this breakpoint to look more like it does without Center Logo on:

When the logo is centred, the tagline has left and right padding, which I think is adding the extra space when it wraps to the new line.

I'll have to do some more digging, but I believe the reason it's wrapping is because the image has a max width wider than the actual image, so with AMP enabled, the amp-img area is taking up more space than the actual img does. Will confirm with some testing!

[laurelfulford]

This also seems to be caused by the centred logo having a narrower 'branding' section, even when it starts being left-aligned on smaller screens. If the branding section was wider, like it is when the logo is left aligned, there should be more space for the tagline.