Global stylesheet can be used to create your own CSS classes that will be applied to all HTML pages
If it does not already exist create a plain text file in the root directory named global_stylesheet.css
you can then create your own classes
.my_new_class {background:#123abc;}
This class will now be available in all building tool blocks that have a class selector or in HTML code on any page
If you leave out the space after the class name it will not be available in the building tool class selector
Global_stylesheet can be disabled for a page in the page options