[Enhancement] Site Titles using em units are different size on homepage and other pages

[jessecowens]

Is your feature request related to a problem? Please describe.
In the Design > Header Site Title control, if the user specifies a font size using em units, the size will differ on the homepage versus other pages on the site. This is because on the homepage, the site-title element uses an h1, and other pages use a paragraph.

Describe the solution you'd like
A responsive font size would be the ideal solution, scaling down for different viewport sizes.

Describe alternatives you've considered
Other solutions include disabling the em unit for this control, or using a consistent element type on each page for the site title.

Additional context
This issue was reported on the WordPress.org Forums.

[jessecowens]

@jamesros161 this issue has been reported by another user on the BoldGrid Support Center