In your Careers Site Settings you’ll see lots of customization options to help you decide exactly how your Careers Site should appear for your candidates. Here's how to style your Careers Site with custom CSS, scripts in your header and body section.
First, go to your Careers Site
Then, click 'Careers Site editor' on the left.
Next, scroll down to 'Custom Styling'.
In the 'Custom CSS' section, you can insert your custom CSS.