Oxygen's visual interface provides controls for many CSS properties, but sometimes you may want to add additional, custom CSS that can't be created with Oxygen's visual controls.
When writing custom CSS, Oxygen displays the result right inside the editor.
Adding CSS Properties to an Element or Class
When editing an element or class, you may specify any additional CSS properties that Oxygen doesn't provide visual controls for. Click Advanced > Custom CSS and add CSS properties you need.
Adding Custom CSS to a Page or Template
Additional CSS can be added to a page or template using the Code Block element, which can be added from +Add -> Basics -> Code Block
Adding Sitewide CSS
Stylesheets that will be loaded on every page of your site can be added from Manage -> Stylesheets.