fix: update Beian component styling for improved visibility and accessibility

src/apps/beian.tsx

@@ -15,7 +15,7 @@ export const Beian = () => {
   const beianInfo = beianList.find(item => hostname.includes(item.hostname.replace('https://', '').replace('http://', '')));
   if (!beianInfo) return null;
   return ( 
-    <div className="text-center text-sm text-gray-500 my-2">
+    <div className="text-center text-sm text-gray-500 my-2 fixed bottom-0 w-full bg-white/70 backdrop-blur-sm py-1">
       <a href="https://beian.miit.gov.cn/" target="_blank" rel="noopener noreferrer" className="hover:underline">
         {beianInfo.beian}
       </a>