feat: optimize performance and fix CLS issues

src/layouts/BaseLayout.astro

@@ -170,13 +170,32 @@ const fullCanonicalUrl = canonicalUrl || `${siteUrl}${Astro.url.pathname}`;
 
 		<link rel="preconnect" href="https://fonts.googleapis.com" />
 		<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+		<link
+			rel="preload"
+			as="font"
+			type="font/woff2"
+			href="https://fonts.gstatic.com/s/inter/v13/UcCO3FwrK3iLTeHuS_fvQtMwCp50KnMw2boKoduKmMEVuLyfAZ9hiA.woff2"
+			crossorigin
+		/>
 
 		<style>
+			/* Fallback font ottimizzato per ridurre layout shift */
+			@font-face {
+				font-family: "Inter-fallback";
+				font-style: normal;
+				font-weight: 400 800;
+				src: local("Arial");
+				ascent-override: 90%;
+				descent-override: 22%;
+				line-gap-override: 0%;
+				size-adjust: 107%;
+			}
+
 			@font-face {
 				font-family: "Inter";
 				font-style: normal;
 				font-weight: 400 800;
-				font-display: swap;
+				font-display: optional;
 				src: url(https://fonts.gstatic.com/s/inter/v13/UcCO3FwrK3iLTeHuS_fvQtMwCp50KnMw2boKoduKmMEVuLyfAZ9hiA.woff2)
 					format("woff2");
 				unicode-range:
@@ -184,6 +203,17 @@ const fullCanonicalUrl = canonicalUrl || `${siteUrl}${Astro.url.pathname}`;
 					U+0329, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF,
 					U+FFFD;
 			}
+
+			/* Previeni flash of unstyled content */
+			body {
+				font-family:
+					"Inter",
+					"Inter-fallback",
+					-apple-system,
+					BlinkMacSystemFont,
+					"Segoe UI",
+					sans-serif;
+			}
 		</style>
 
 		<link rel="icon" type="image/x-icon" href="/favicon.ico" />