Computed values
The values you check first, and a search across every property.
Computed is what the Code section opens on. It shows the values you check first, in order: size, padding, margin, border and radius, display and layout, then type and colour, leaving out any that are still at their default. Lengths are in pixels, colours as rgb(). Any other property is a search away: the field searches all of them, custom properties (--…) included, by property or value, and Copy puts what is shown on the clipboard as CSS.
Stylesheets served from another site (a CDN, for example) cannot be read by a browser extension without asking for permission to every site, which Nitpique does not do. The panel tells you how many were skipped, and their rules are not listed. The computed values are still right, because the browser has already applied them.
Questions
Why are some properties not listed?
Computed leaves out values still at their default. Any other property, custom properties included, is a search away.
Are computed values right when stylesheets are skipped?
Yes. The browser has already applied them.