WPyogi on "Remove H1 from Header & Footer with Tisa Theme"

That's really not necessary - and CSS won't change tags coded into the theme files. If you're determined to do it, you'd need to find all the h1 tags in the .php files AND all the corresponding CSS.

For more help, you'd need to ask the theme developers - here:

http://themify.me/category/showcase/tisa-theme