Version 7.1 - Customized Landing Pages

I'm not a coder.  Current website v. 7.0.  Goal is to create normal size landing pages (niche market sales pages) that would be directed to main check out page.  I don't want a header or footer on these pages. Discovered I can't do this type of landing page, even with a header/footer using v. 7.0.  Apparently v. 7.1 can create a full size landing page BUT needs to have a header/footer.  If I secure a paid v. 7.1 website, I would like to house these landing pages there and direct them to the v. 7.0 site check out page.  Squarespace support tells me the only way I can get rid of the header/footer on these landing pages in v. 7.1 is to customize the code.  SO how can I get rid of these header/footers?  Suggestions would be most welcome.  Thank you.

Edit page >> Add a Code Block >> Paste this code to remove header/footer

<style>
  header#header, footer.sections {
  	display: none !important;
  }
</style>