chore: 置顶 Tag 加大到 lg

src/components/PostCard.astro

@@ -57,7 +57,7 @@ const { remarkPluginFrontmatter } = await render(entry);
             <span class="flex flex-wrap items-center gap-x-3 gap-y-2">
                 {isPinned && (
                     <span class="inline-flex items-center gap-1 rounded-full border border-[var(--primary)]/20 bg-[var(--primary)]/10 px-2.5 py-1 text-xs font-semibold text-[var(--primary)] leading-none">
-                        <Icon name="material-symbols:keep-rounded" class="text-sm"></Icon>
+                        <Icon name="material-symbols:keep-rounded" class="text-lg"></Icon>
                         置顶
                     </span>
                 )}