When i include a form on a page its button:not() theme.css is overriding styles defined by classes on other button components on the page
What should i do to get the style on button class xyz
WHy not put your CSS applicable to the Form in its own ClientLib - then it will not impact other parts of the site.
I am using the default theme.css for the form component. When this component is dragged on a page that contains other components having button. It overrides there styles.
Try putting the CSS into a separate clientlib that will not impact other parts of the site. That is only used in the form where you want that specific style.