Naven
Glossary
Core Web Vitals
Google's three measurements of whether a page feels fast to the person using it.
Largest Contentful Paint asks when the main thing appeared, Interaction to Next Paint asks how quickly the page answers a tap, and Cumulative Layout Shift asks whether things moved under the reader's finger. They are field measurements from real visits rather than lab numbers.
They are a ranking input, but the better argument for them is that they measure the experience directly: a page that fails them is genuinely unpleasant.
Where Naven stands
Naven's public pages are static HTML with one stylesheet and no framework, which is most of what these metrics reward.