Fortunately, you can use Tumblr's HTML editor, located on the Customize page, to change the ... third-party Web font you must add an extra block of code attaching the font's CSS to your theme.

A CSS file that contains this single line will change the typeface on all pages to Arial: html body { font-family: Arial !important } Decoded, that says “for an HTML page’s body section ...

Fortunately, Tumblr enables you to change the font size for ... Scroll through the HTML code until you find the styles section beneath the line " How to Customize CSS in Blogspot.