about label CSS

Webix JS
1

http://webix.com/snippet/2d945e57

Why I can only change HTML through style label(username field).The password field used css but label don’t change

2

Usually, setting a new style means extending the existent one:

http://webix.com/snippet/135692ad

You can get the default CSS-classes from the CSS Maps or by inspecting the html of the widgets.