feat: update tag and timeline share panel copy for clarity and conciseness

style: enhance global CSS for better responsiveness of terminal chips and navigation pills

test: remove inline subscription test and add maintenance mode access code test

feat: implement media library picker dialog for selecting images from the media library

feat: add media URL controls for uploading and managing media assets

feat: add migration for music_enabled and maintenance_mode settings in site settings

feat: implement maintenance mode functionality with access control

feat: create maintenance page with access code input and error handling

chore: add TypeScript declaration for QR code module

frontend/src/pages/articles/[slug].astro

@@ -92,20 +92,20 @@ const articleMarkdown = contentText.replace(/^#\s+.+\r?\n+/, '');
 const paragraphCommentsEnabled = siteSettings.comments.paragraphsEnabled;
 const articleCopy = isEnglish
   ? {
-      digestBadge: 'featured digest',
-      digestKicker: 'ai digest',
-      digestTitle: 'AI / search summary',
+      digestBadge: 'quick brief',
+      digestKicker: 'reading preview',
+      digestTitle: 'Read this first',
       digestDescription:
-        'This block exposes a compact summary, key takeaways, and canonical follow-up paths for AI search and human skimming.',
+        'A short overview of the article so readers can quickly grasp the key points before sharing or saving it.',
       highlightsTitle: 'Key takeaways',
       faqTitle: 'Quick FAQ',
-      sourceTitle: 'Canonical source signals',
+      sourceTitle: 'Page details',
       readTime: 'Read time',
       insightCount: 'Key points',
       faqCount: 'FAQ',
       updated: 'Updated',
       category: 'Category',
-      canonical: 'Canonical',
+      canonical: 'Permalink',
       keywords: 'Keywords',
       copySummary: 'Copy digest',
       copySuccess: 'Digest copied',
@@ -114,39 +114,39 @@ const articleCopy = isEnglish
       shareSuccess: 'Share panel opened',
       shareFallback: 'Share text copied',
       shareFailed: 'Share failed',
-      shareChannelsTitle: 'Quick share',
+      shareChannelsTitle: 'Share options',
       shareChannelsDescription:
-        'Push this article to social channels with a shorter path, so people and AI search tools can pick up the canonical link faster.',
+        'Copy the overview or permalink, or continue sharing through the channels below.',
       shareToX: 'Share to X',
       shareToTelegram: 'Share to Telegram',
-      shareToWeChat: 'WeChat QR',
-      qrModalTitle: 'WeChat scan share',
-      qrModalDescription: 'Scan this local QR code in WeChat to open the canonical article URL on mobile.',
-      qrModalHint: 'Prefer sharing the canonical link so users and AI engines can fold signals back to one source.',
+      shareToWeChat: 'WeChat scan',
+      qrModalTitle: 'Scan with WeChat',
+      qrModalDescription: 'Scan this QR code in WeChat to continue reading the article on mobile.',
+      qrModalHint: 'When you want to send the article to someone else, copying the permalink below is usually the easiest option.',
       downloadQr: 'Download QR',
       downloadQrStarted: 'QR download started',
       qrOpened: 'WeChat QR ready',
-      floatingToolsTitle: 'Digest tools',
+      floatingToolsTitle: 'Quick actions',
       copyPermalinkSuccess: 'Permalink copied',
       copyPermalinkFailed: 'Permalink copy failed',
       toastSuccessTitle: 'Done',
       toastErrorTitle: 'Action failed',
-      toastInfoTitle: 'Share ready',
+      toastInfoTitle: 'Ready',
     }
   : {
-      digestBadge: '精选摘要',
-      digestKicker: 'ai digest',
-      digestTitle: 'AI / 搜索摘要',
-      digestDescription: '这块内容会把页面结论、重点摘录和规范入口显式写出来，方便 AI 搜索和用户快速理解。',
+      digestBadge: '文章导读',
+      digestKicker: '阅读前速览',
+      digestTitle: '先看重点',
+      digestDescription: '先用几句话帮你抓住这篇文章的重点，方便快速浏览、收藏或转发。',
       highlightsTitle: '关键信息',
       faqTitle: '快速问答',
-      sourceTitle: '规范来源信号',
+      sourceTitle: '页面信息',
       readTime: '阅读时长',
       insightCount: '重点条数',
       faqCount: '问答条数',
       updated: '最近更新',
       category: '归档分类',
-      canonical: '规范地址',
+      canonical: '固定链接',
       keywords: '关键词',
       copySummary: '复制摘要',
       copySuccess: '摘要已复制',
@@ -155,23 +155,23 @@ const articleCopy = isEnglish
       shareSuccess: '已打开分享面板',
       shareFallback: '分享文案已复制',
       shareFailed: '分享失败',
-      shareChannelsTitle: '快速分发',
-      shareChannelsDescription: '用更短路径把这篇内容发到社交渠道，方便二次传播和 AI 引用回链。',
+      shareChannelsTitle: '分享方式',
+      shareChannelsDescription: '可以直接复制摘要、固定链接，或通过常用渠道继续转发。',
       shareToX: '分享到 X',
       shareToTelegram: '分享到 Telegram',
-      shareToWeChat: '微信扫码',
-      qrModalTitle: '微信扫码分享',
-      qrModalDescription: '使用本地生成的二维码，在微信里扫一扫，就能直接打开这篇文章的规范链接。',
-      qrModalHint: '尽量分享规范地址，方便用户回访，也方便 AI 搜索把信号聚合回同一篇内容。',
+      shareToWeChat: '微信扫一扫',
+      qrModalTitle: '微信扫一扫',
+      qrModalDescription: '用微信扫一扫，就能在手机上继续阅读这篇文章。',
+      qrModalHint: '发给别人时，优先复制固定链接，对方打开会更方便。',
       downloadQr: '下载二维码',
       downloadQrStarted: '二维码开始下载',
       qrOpened: '微信二维码已打开',
-      floatingToolsTitle: '摘要工具',
+      floatingToolsTitle: '快捷操作',
       copyPermalinkSuccess: '固定链接已复制',
       copyPermalinkFailed: '固定链接复制失败',
       toastSuccessTitle: '操作完成',
       toastErrorTitle: '操作失败',
-      toastInfoTitle: '分享渠道已就绪',
+      toastInfoTitle: '已准备好',
     };
 
 const markdownProcessor = await createMarkdownProcessor();
@@ -236,7 +236,7 @@ if (wechatShareQrEnabled) {
     wechatShareQrSvg = await QRCode.toString(canonicalUrl, {
       type: 'svg',
       margin: 1,
-      width: 220,
+      width: 240,
       color: {
         dark: '#111827',
         light: '#ffffff',
@@ -244,7 +244,7 @@ if (wechatShareQrEnabled) {
     });
     wechatShareQrPngDataUrl = await QRCode.toDataURL(canonicalUrl, {
       margin: 1,
-      width: 360,
+      width: 420,
       color: {
         dark: '#111827',
         light: '#ffffff',
@@ -434,55 +434,7 @@ const breadcrumbJsonLd = {
                 <div class="absolute inset-y-0 left-0 w-1 rounded-full bg-[var(--primary)]/80"></div>
                 <div class="absolute right-0 top-0 h-36 w-36 rounded-full bg-[var(--primary)]/10 blur-3xl"></div>
                 <div class="absolute bottom-0 right-10 h-24 w-24 rounded-full bg-[var(--secondary)]/10 blur-3xl"></div>
-                <div class="pointer-events-none absolute right-4 top-4 z-10 hidden xl:block">
-                  <div class="pointer-events-auto rounded-2xl border border-[var(--border-color)]/70 bg-[var(--terminal-bg)]/88 px-2 py-2 shadow-[0_10px_28px_rgba(15,23,42,0.08)] backdrop-blur">
-                    <div class="mb-2 px-2 text-[10px] font-semibold uppercase tracking-[0.22em] text-[var(--text-tertiary)]">
-                      {articleCopy.floatingToolsTitle}
-                    </div>
-                    <div class="flex items-center gap-2">
-                      <button
-                        type="button"
-                        class="flex h-10 w-10 items-center justify-center rounded-xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
-                        data-article-floating-action="digest-copy"
-                        title={articleCopy.copySummary}
-                        aria-label={articleCopy.copySummary}
-                      >
-                        <i class="fas fa-copy text-sm"></i>
-                      </button>
-                      <button
-                        type="button"
-                        class="flex h-10 w-10 items-center justify-center rounded-xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
-                        data-article-floating-action="digest-share"
-                        title={articleCopy.shareSummary}
-                        aria-label={articleCopy.shareSummary}
-                      >
-                        <i class="fas fa-share-nodes text-sm"></i>
-                      </button>
-                      {wechatShareQrEnabled && wechatShareQrSvg && (
-                        <button
-                          type="button"
-                          class="flex h-10 w-10 items-center justify-center rounded-xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
-                          data-article-floating-action="wechat-qr"
-                          title={articleCopy.shareToWeChat}
-                          aria-label={articleCopy.shareToWeChat}
-                        >
-                          <i class="fab fa-weixin text-sm"></i>
-                        </button>
-                      )}
-                      <button
-                        type="button"
-                        class="flex h-10 w-10 items-center justify-center rounded-xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
-                        data-article-floating-action="permalink-copy"
-                        title={t('common.copyPermalink')}
-                        aria-label={t('common.copyPermalink')}
-                      >
-                        <i class="fas fa-link text-sm"></i>
-                      </button>
-                    </div>
-                  </div>
-                </div>
-
-                <div class="relative grid gap-5 lg:grid-cols-[minmax(0,1.4fr)_minmax(19rem,0.95fr)]">
+                <div class="relative grid gap-5 xl:grid-cols-[minmax(0,1.4fr)_minmax(19rem,0.95fr)]">
                   <div class="space-y-5">
                     <div class="flex flex-wrap items-center gap-2">
                       <span class="inline-flex items-center gap-2 rounded-full border border-[var(--primary)]/20 bg-[var(--primary)]/10 px-3 py-1 text-[11px] font-semibold uppercase tracking-[0.24em] text-[var(--primary)]">
@@ -490,7 +442,7 @@ const breadcrumbJsonLd = {
                         {articleCopy.digestBadge}
                       </span>
                       <span class="terminal-kicker">
-                        <i class="fas fa-robot"></i>
+                        <i class="fas fa-book-open"></i>
                         {articleCopy.digestKicker}
                       </span>
                     </div>
@@ -591,25 +543,6 @@ const breadcrumbJsonLd = {
                       ))}
                     </div>
 
-                    {articleHighlights.length > 0 && (
-                      <div class="space-y-3">
-                        <h3 class="text-sm font-semibold uppercase tracking-[0.22em] text-[var(--text-tertiary)]">
-                          {articleCopy.highlightsTitle}
-                        </h3>
-                        <div class="grid gap-3 sm:grid-cols-2 xl:grid-cols-3">
-                          {articleHighlights.map((item, index) => (
-                            <div class="rounded-2xl border border-[var(--border-color)]/80 bg-[var(--terminal-bg)]/80 p-4 shadow-[0_10px_30px_rgba(15,23,42,0.04)]">
-                              <div class="flex items-start gap-3">
-                                <span class="inline-flex h-8 w-8 shrink-0 items-center justify-center rounded-xl bg-[var(--primary)]/12 text-sm font-semibold text-[var(--primary)]">
-                                  {String(index + 1).padStart(2, '0')}
-                                </span>
-                                <p class="text-sm leading-7 text-[var(--text-secondary)]">{item}</p>
-                              </div>
-                            </div>
-                          ))}
-                        </div>
-                      </div>
-                    )}
                   </div>
 
                   <div class="space-y-4">
@@ -867,7 +800,60 @@ const breadcrumbJsonLd = {
         </section>
       </div>
 
-      <TableOfContents />
+      <TableOfContents>
+        <div slot="before-nav" class="terminal-panel-muted space-y-3">
+          <span class="terminal-kicker">
+            <i class="fas fa-bolt"></i>
+            {articleCopy.floatingToolsTitle}
+          </span>
+
+          <div
+            class:list={[
+              'grid gap-2',
+              wechatShareQrEnabled && wechatShareQrSvg ? 'grid-cols-4' : 'grid-cols-3',
+            ]}
+          >
+            <button
+              type="button"
+              class="flex h-11 w-full items-center justify-center rounded-2xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
+              data-article-floating-action="digest-copy"
+              title={articleCopy.copySummary}
+              aria-label={articleCopy.copySummary}
+            >
+              <i class="fas fa-copy text-sm"></i>
+            </button>
+            <button
+              type="button"
+              class="flex h-11 w-full items-center justify-center rounded-2xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
+              data-article-floating-action="digest-share"
+              title={articleCopy.shareSummary}
+              aria-label={articleCopy.shareSummary}
+            >
+              <i class="fas fa-share-nodes text-sm"></i>
+            </button>
+            {wechatShareQrEnabled && wechatShareQrSvg && (
+              <button
+                type="button"
+                class="flex h-11 w-full items-center justify-center rounded-2xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
+                data-article-floating-action="wechat-qr"
+                title={articleCopy.shareToWeChat}
+                aria-label={articleCopy.shareToWeChat}
+              >
+                <i class="fab fa-weixin text-sm"></i>
+              </button>
+            )}
+            <button
+              type="button"
+              class="flex h-11 w-full items-center justify-center rounded-2xl border border-[var(--border-color)]/70 bg-[var(--bg)]/75 text-[var(--text-secondary)] transition hover:border-[var(--primary)] hover:text-[var(--primary)]"
+              data-article-floating-action="permalink-copy"
+              title={t('common.copyPermalink')}
+              aria-label={t('common.copyPermalink')}
+            >
+              <i class="fas fa-link text-sm"></i>
+            </button>
+          </div>
+        </div>
+      </TableOfContents>
     </div>
   </div>
 
@@ -878,7 +864,7 @@ const breadcrumbJsonLd = {
       aria-hidden="true"
     >
       <div class="flex min-h-screen items-center justify-center p-4">
-        <div class="w-full max-w-3xl rounded-[30px] border border-[var(--border-color)] bg-[linear-gradient(180deg,rgba(var(--bg-rgb),0.98),rgba(var(--bg-rgb),0.92))] p-5 shadow-[0_24px_80px_rgba(15,23,42,0.28)] sm:p-6">
+        <div class="w-full max-w-4xl rounded-[32px] border border-[var(--border-color)]/70 bg-[var(--terminal-bg)] p-5 shadow-[0_30px_90px_rgba(15,23,42,0.36)] sm:p-7">
           <div class="flex items-start justify-between gap-4">
             <div class="space-y-2">
               <span class="terminal-kicker">
@@ -903,24 +889,25 @@ const breadcrumbJsonLd = {
             </button>
           </div>
 
-          <div class="mt-6 grid gap-6 lg:grid-cols-[240px_minmax(0,1fr)]">
-            <div class="mx-auto w-full max-w-[240px] rounded-[28px] border border-[var(--border-color)]/80 bg-white p-4 shadow-[0_18px_45px_rgba(15,23,42,0.12)]">
+          <div class="mt-6 grid gap-6 lg:grid-cols-[260px_minmax(0,1fr)]">
+            <div class="mx-auto w-full max-w-[260px] rounded-[28px] border border-[var(--border-color)]/80 bg-white p-5 shadow-[0_18px_45px_rgba(15,23,42,0.12)]">
               <div class="overflow-hidden rounded-2xl" set:html={wechatShareQrSvg}></div>
             </div>
 
             <div class="space-y-4">
-              <div class="rounded-2xl border border-[var(--border-color)]/70 bg-[var(--terminal-bg)]/82 p-4">
+              <div class="rounded-2xl border border-[var(--border-color)]/70 bg-[var(--header-bg)] p-5">
                 <div class="text-[11px] uppercase tracking-[0.2em] text-[var(--text-tertiary)]">
                   {articleCopy.canonical}
                 </div>
-                <p class="mt-2 break-all font-mono text-xs leading-6 text-[var(--title-color)]">{canonicalUrl}</p>
+                <p class="mt-3 break-all font-mono text-sm leading-7 text-[var(--title-color)]">{canonicalUrl}</p>
               </div>
 
-              <div class="rounded-2xl border border-[var(--border-color)]/70 bg-[var(--terminal-bg)]/72 p-4">
+              <div class="rounded-2xl border border-[var(--border-color)]/70 bg-[var(--header-bg)] p-5">
                 <div class="text-[11px] uppercase tracking-[0.2em] text-[var(--text-tertiary)]">
                   {articleCopy.digestTitle}
                 </div>
-                <p class="mt-2 text-sm font-semibold leading-7 text-[var(--title-color)]">{post.title}</p>
+                <p class="mt-3 text-base font-semibold leading-7 text-[var(--title-color)]">{post.title}</p>
+                <p class="mt-3 text-sm leading-7 text-[var(--text-secondary)]">{articleSynopsis}</p>
                 <p class="mt-3 text-sm leading-7 text-[var(--text-secondary)]">{articleCopy.qrModalHint}</p>
               </div>