How can I create a completely blank page so that it does inherit the styling of the rest of the website.

How can I create a completely blank page on Squarespace that doesn't inherit the website's existing styling, allowing me to use my own HTML for the entire page?

It's not possible to create a page that doesn't inherit site styles, but you could override them all on that page. You could hide the header and footer, create the content you need and then restyle with CSS. Not sure how custom you're needing the page to be though.