Global Stylesheets
While Ionic Framework component styles are self-contained, there are several global stylesheets that should be included in order to use all of Ionic's features. Some of the stylesheets are required in order for an Ionic Framework app to look and behave properly, and others include optional utilities to quickly style your app.
Available
Required
The following CSS file must be included in order for Ionic Framework to work properly.
core.css
This file is the only stylesheet that is required in order for Ionic components to work properly. It includes app specific styles, and allows the color property to work across components. If this file is not included the colors will not show up and some elements may not appear properly.
Recommended
The following CSS files are recommended to be included in an Ionic Framework app. If they are not included, some elements may have undesired styles. If Ionic Framework components are being used outside of an app, these files may not be necessary.
structure.css
Applies styles to <html> and defaults box-sizing to border-box. It ensures scrolling behaves like native in mobile devices.