It depends on your version, and the two are nothing alike. In Squarespace 7.1 there is no such thing as a banner

Click Edit on any page, hover over the footer, and click Edit footer. From there you are editing sections,

Click Edit in the top-left of your site preview, hover the header, then click Edit site header. Everything structural

Paste these into Website → Website Tools → Custom CSS. Every selector below was checked against live Squarespace 7.1

Squarespace 7.1 does not let you set colours element by element. You set a five-colour palette in Site Styles

Squarespace 7.1 has one template family, so customising a template means working three layers in a fixed order

If the Squarespace editor is the thing misbehaving, a Chrome extension is the cause about half the time

 A blank Squarespace page is almost always custom code you added, not a Squarespace fault, and almost always fully recoverable.

Something further down the cascade is beating Site Styles, and in most cases it is Custom CSS you

If the embed is blank while you're logged in, nothing is broken. Squarespace disables embedded scripts

The product's Visibility is almost certainly set to Hidden or Scheduled rather than Public. In Squarespace 7.1

 If you're seeing Times New Roman or a generic sans-serif where your font should be, the font file never loaded…

 In Squarespace 7.1 there is no separate publish step — saving an edit makes it live immediately on a public site.

 your browser is almost certainly serving a cached icon. Browsers cache favicons far more aggressively than they cache pages, and a normal refresh will not touch them. Load your site in a private window first. If the favicon appears there, the file uploaded correctly and you are looking at cache. If it is missing there too, the problem is the file itself — usually format or file size.

 If your Squarespace 7.1 store shows "Checkout is closed. This store isn't set up to take orders",

If a page is missing from your menu, it's almost certainly sitting in the Not linked section of the Pages panel.

You cannot manually force a Squarespace certificate to issue — but you can remove what's blocking it.

The Squarespace 7.1 mobile menu is almost never broken by Squarespace. Tapping the burger adds a

Most Squarespace images are not broken, they are unloaded. Squarespace 7.1 ships images with an empty

In most cases the code is fine and you are looking at it from the wrong place. Squarespace deliberately disables