Core Web Vitals optimization guide for 2026 starts with one hard truth: Google ranks on real-user field data, not your Lighthouse lab score. If your CrUX numbers fail at the 75th percentile, the pretty 95 you see in PageSpeed Insights will not save you. The three metrics that still matter are Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout...