How do I hide the header on a specific page in Squarespace?

Every page in Squarespace 7.1 gets a unique collection ID on the body or a wrapping div. You can use this to target CSS to just that page. Find the ID by inspecting the page source or using a browser extension.

Once you have the collection ID, scope your header-hiding rule to that selector. This keeps the header visible on every other page while removing it completely from the one you choose.

/* Replace with your page's collection ID */
.collection-681a2b3c4d5e6f7a8b9c0d1e {
  #header {
    display: none !important;
  }

  /* Remove the top spacing the header normally occupies */
  .content-wrapper {
    padding-top: 0 !important;
  }
}