/*change font size for Heading 2 on a specific page*/
    1.     #(pageID) H2 {font-size: 1.5em;}

(pageID)  replace with page ID #.  Set Heading size as needed (1,2,3, ... )

collection-57d9b4c2c534a59ea680c54b

    1.     #collection-57d9b4c2c534a59ea680c54b H2 {font-size: 1.5em;}