After testing, the maximum size to record a simulation in Storyline that will be scaled 100% (so not fuzzy etc) and fit on a monitor with 1024×768 resolution is… DRUMROLL
This fits maximised from 1024×768 in Chrome, Firefox and IE.
Code for the popup window:
To make the scrollbars go away in Chrome, in the publish shell (story.html), need to add ‘overflow-x:hidden; overflow-y:hidden’ to the html CSS tag at the top of the source code.
This code is optimised for IE 11; the Storyline bottom and right borders are slightly covered in Firefox and Chrome – no biggy.
For 16:9, same deal – story size can be 988×556 to fit horizontally on a 4:3 1024×768 resolution at 100%.