diff --git a/components/social/mention-autocomplete.tsx b/components/social/mention-autocomplete.tsx
index b1c94281..5e42d451 100644
--- a/components/social/mention-autocomplete.tsx
+++ b/components/social/mention-autocomplete.tsx
@@ -125,7 +125,9 @@ export function MentionAutocomplete({
           }}
           placeholder={placeholder}
           autoComplete="off"
-          className="w-full rounded-lg border border-border bg-background py-2 pl-9 pr-3 text-sm text-foreground outline-none placeholder:text-muted-foreground focus-visible:ring-2 focus-visible:ring-ring"
+          // text-base (16px) on mobile prevents iOS Safari from auto-zooming
+          // on focus (it zooms any input < 16px); compact 14px on desktop.
+          className="w-full rounded-lg border border-border bg-background py-2 pl-9 pr-3 text-base sm:text-sm text-foreground outline-none placeholder:text-muted-foreground focus-visible:ring-2 focus-visible:ring-ring"
         />
       </div>