This article will guide you through a process of adding custom CSS styling to either a theme (which may be used by one or more experiences) or a specific experience.

Adding CSS to a theme

1. Go to your themes list and click the settings icon on your theme to Edit Theme.
2. Add your CSS to the left panel, click apply to confirm the changes.

Adding CSS styling customization to a single experience

1. Go to your experience and find the Advanced drop down on the left. Open it and click Customize and click Edit on the Custom CSS option.
2. Add your CSS into the window that appears and click Apply to save your changes. 

You should take time to test any customization added to a theme or experience, ensuring that experience appears the way you expect across all supported browsers.