Hello, I recently started my two site named LoginWorldz.com and LoginWelt.com and I want to see the settings of font and header logo size for mobile version of sites.
Thanks and Regards
Regarding your query, Magento does not provide such kind of setting for mobile screens.
So, you need to add CSS for the logo and font size.
Magento 2 logo change & logo size
Your current store theme determines the size and location of the logo by default. The default Magento 2 logo is saved as an SVG file. The desired logo can be saved in any of the file types: GIF, PNG, JPG, or JPEG and uploaded from the admin panel of your website.
To find the default Magento logo and change it for a new one, navigate to:
The Admin Panel> Content> Configuration> Select Your Current Theme> Header;
!For Magento 2.x.x - Magento 2.1.x use this path: the Admin Panel> Stores> Settings> Configuration> General> Design> Header!