If you change the width of a screen profile, the media query for the screen profile defined in the style sheet becomes undefined. RoboHelp does not automatically update the media query. Follow these steps to map an undefined media query to a media:
1)Right-click the CSS file and select Edit.
2)In the Styles dialog box, select Manage Media Queries from the Media list.
3)Select the undefined media query that has the width you specified and click Map.
4)Select the screen profile name.