Fix theme consistency, i18n completeness, CSS variable naming, and hardcoded strings

src/app/admin/users/[id]/edit/page.tsx

@@ -96,7 +96,7 @@ export default async function AdminUserEdit({
       <form action={updateUser} className="admin-card">
         <input type="hidden" name="id" value={user.id} />
 
-        <div className="grid cols-2">
+        <div className="grid grid-cols-1 gap-4 md:grid-cols-2">
           <label>
             {t("email")}
             <input name="mail" type="email" defaultValue={user.mail ?? ""} maxLength={500} />