If you want to go beyond basic HTML with you Microsites, you may access the Kendo UI library that is already included on the page.
Kendo UI is jQuery library that is included in the page for functions that we access. You can see demos and get the code for the interface elements that are possible with Kendo UI.
There is no development cost to you from Matrix to use the libraries we already have in place on the page for our own development. If something needs to be added to support what you are trying to do, that would be additional cost, if it is possible for us to add at all.
To add any advanced code, you will need to switch the WYSIWYG to source view and manually code the HTML.