Here is a simple way to define style sheets for cross platform environment (Version 6.5.x and 6.0.x)
When trying to define style sheets for use in a cross-platform environment you need to assign fonts, font sizes and font styles for each platform interface (Mac OS, Windows NT 3.5.1 and 95). You edit style sheets in the object properties dialog of the form editor.
Obviously, when you are editing those style sheets on one machine, the fonts displayed in the font menu match only those available on that machine. Instead of trying to find a font that has the same name on both Windows and Mac OS, it is simpler to connect, for each platform, a client from a machine that has the adequate OS and edit all style sheets for that platform. By doing this, you can display and address the formatting issues for each platform at once. The only constraint you have to respect is that you should make sure the fonts you select for a platform/style sheet are available on all that platform's clients.