Something like:
.profile-desktop .mx-window { width: 60%; }
Above I set my default popup width to 60%. If I also add the following 2 items to my theme css:
.narrow { width: 30% !important; } .wide { width: 90% !important; }I can then choose an individual narrow (30%) or wide (90%) width by setting the appropriate Class to the pop-up page in the modeler: