tns-template-hello-world/app/app.css

Nativescript hello-world project template

/*
In NativeScript, the app.css file is where you place CSS rules that
you would like to apply to your entire application. Check out
http://docs.nativescript.org/ui/styling for a full list of the CSS
selectors and properties you can use to style UI components.

/*
In many cases you may want to use the NativeScript core theme instead
of writing your own CSS rules. You can learn more about the 
NativeScript core theme at https://github.com/nativescript/theme
The imported CSS rules must precede all other types of rules.
*/
@import "~@nativescript/theme/css/core.css";
@import "~@nativescript/theme/css/default.css";

/* Place any CSS rules you want to apply on both iOS and Android here.
This is where the vast majority of your CSS code goes. */

/*
The following CSS rule changes the font size of all Buttons that have the
"-primary" class modifier.
*/
Button.-primary {
    font-size: 18;
}