I am encountering an issue with MicroThemer and EventIn (or I guess any WP “template”). When attempting to edit an EventIn event page with MicroThemer, the changes I make are applied to all event pages, rather than just the page I am editing.
I think this is more a newbie question than a real issue.
To make your styles specific to the current page you are working on, you can enabled the page-id option when targeting elements. The “Selecting elements” video shows this: https://themeover.com/selecting-elements/?seekTo=613
And an upcoming feature, which should hopefully be released as a beta today supports assigning Microthemer folders to specific pages. So all the CSS in the folder will load on one or more pages you specify, rather than as part of a global stylesheet included on all pages.
I expect this feature to be available for general release in a couple of weeks.
I hope that helps. Please let me know of you have any further questions.