Magento Core Web Vitals — The Actual LCP, INP & CLS Recipe
Four real diagnoses from production Magento + Hyvä stores in 2026. LCP element pinned in DevTools Performance (usually the hero image or an H1 stuck in font-swap), a 10 KiB inline critical CSS budget, a 1200w / 800w / 480w WebP <picture> matrix, INP traced to a 3-second Knockout boot on Luma checkouts, and CLS killed by reserving min-height on the cookie banner. Real Lighthouse JSON excerpts, a recipe checklist, and the mobile P=52 → P=88 numbers that came out the other side.