[Gridsphere-users] What makes the different themes work?

[Hj]

Hi~

As mentioned in the title , I wonder what makes the different themes work?
Recently , i found we could change the "tab"'s display by change the theme from
"default" to "purple".
If we do this , the display of Gridsphere will completely change, i mean , from
the default "2-level" tab to "listed menu" tab.
How many files i should change if i want to do another theme to change the default
"2-level" tab to another display mode? And , What are they?