The Order Bump plugin lets apply CSS to your order bump blocks.
You can add them by going into the Global Settings of Order Bump.
Simply follow the steps below:
Step 1: Click on the 'Settings' tab from FunnelKit menu
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When you do so, you'll see the Global Settings section of Order Bump.
Step 2: Add the custom CSS
In the global settings of Order Bump, the first option is the 'Global Custom CSS'.
Add your custom CSS in the text area.
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This custom CSS applies to all the pages. Once you're done, hit the 'Save Changes' button.
There you go! You've now successfully added custom CSS for your order bump blocks.