I am using the mantra settings to adjust the header on my site and have successfully uploaded a custom logo on top of my header image. But according to the drop down options I can’t chose ‘custom logo’ and ‘site title and description’.
And then which lines in css am I looking at to then adjust the site title formatting, centre it, shadow, font, font size, etc?
You can’t display both the logo and site title/tagline simultaneously without quite a bit of code editing.
Use a dev tool like Firebug to inspect the title and tagline and figure out the necessary tags.
Centering will be quite tricky though (especially if you also want to keep responsiveness working).