For more information on Markdown support in PhpStorm, refer to the Markdown section.
From the list, select how the editor will be shown by default: both editor and preview panes, editor only, or preview only pane.
Select this checkbox to automatically scroll from the cursor position in the source code to the respective position in the preview.
Select this checkbox to use grayscale for rendering.
PlantUML framework isn't installed
This warning appears if the PlantUML framework is not installed. If you need to display the PlantUML diagrams in the Markdown preview, click Install.
Disable automatic language injection in code fences
Select this checkbox to disable code injection in fenced code blocks.
Hide errors in code fences
Select this checkbox to disable error highlighting in fenced code blocks.
Load from URI
Specify here the path to the desired .css file. Click to find the file in the file system.
Add CSS rules
Type a particular CSS to be used for rendering the preview. For example, you can specify here the background color and font weight.