feat(ui): update UI v1

frontend/src/pages/ArticleDetail.tsx

@@ -1,9 +1,9 @@
 import React from 'react';
 import { Link, useParams } from 'react-router-dom';
-import { ArrowLeftIcon, ChevronLeftIcon, ChevronRightIcon } from 'lucide-react';
+import { ChevronLeftIcon, ChevronRightIcon } from 'lucide-react';
 import { renderToHTMLString } from '@tiptap/static-renderer';
 import { Reveal } from '../components/Reveal';
-import { ButtonLink } from '../components/Button';
+import { PremiumButton } from '../components/PremiumButton';
 import { ArticleCard } from '../components/ArticleCard';
 import { ArticleMeta } from '../components/ArticleMeta';
 import { TableOfContents, extractToc, type TocItem } from '../components/TableOfContents';
@@ -74,10 +74,9 @@ export function ArticleDetail() {
       <section className="flex min-h-[70vh] flex-col items-center justify-center px-6 text-center">
         <h1 className="text-section font-bold text-ivory">{t('articleNotFound')}</h1>
         <p className="mt-4 text-sm font-light text-ivory/60">{t('articleNotFoundText')}</p>
-        <ButtonLink to={href('/blog')} variant="copper" className="mt-8">
+        <PremiumButton to={href('/blog')} className="mt-8">
           {t('backToBlog')}
-          <ArrowLeftIcon className="h-4 w-4 ltr:-scale-x-100" />
-        </ButtonLink>
+        </PremiumButton>
       </section>);
 
   }