Selector Detector is an advanced utility tool that helps you to detect CSS selectors for HTML output displayed inside Oxygen. It is most commonly used to create styles for plugin output, like contact forms inside of Oxygen.
Selector Detector is available for Widgets, Shortcodes, Code Blocks, and some other Oxygen elements that output nested HTML.
Enabling Selector Detector
Selector Detector must be enabled before it can be used. To enable it, from the WordPress admin panel, go to Oxygen -> Settings and check the Enable Selector Detector checkbox.
Detecting CSS Selectors
To find a selector using the Selector Detector, click the Widget, Shortcode, Code Block or other element you wish to detect selectors for. If Selector Detector is available for this element, a Style Output button will appear at the bottom of the left panel.
Click Style Output, then click any content inside of the active element to detect selectors for it.
Managing Selectors
After selectors have been added to a site, they can be managed through the 
Selectors Pane in Oxygen. By default, they will be found in the Uncategorized folder within the Uncategorized Custom Selectors set.
