主题功能同步：vivid 页脚补社交按钮排（含源码入口，居中）；classic 文章页补右栏目录（滚动高亮）与顶部阅读进度条——快发盒经核实两套 UI 均已存在，无需补

frontend/src/views/PostView.vue

@@ -1,5 +1,5 @@
 <script setup>
-import { computed, onMounted, ref, watch } from 'vue'
+import { computed, onBeforeUnmount, onMounted, ref, watch } from 'vue'
 import { useRoute } from 'vue-router'
 import LeftNav from '../components/LeftNav.vue'
 import RightRail from '../components/RightRail.vue'
@@ -33,6 +33,14 @@ function withHeadingIds(html) {
 const contentHtml = ref('')
 const headings = ref([])
 
+// 顶部阅读进度条（classic）：滚动过正文才算数，短文太短不显示
+const progress = ref(0)
+function onScroll() {
+  const doc = document.documentElement
+  const total = doc.scrollHeight - window.innerHeight
+  progress.value = total > 300 ? Math.min(100, (window.scrollY / total) * 100) : 0
+}
+
 async function load() {
   loading.value = true
   error.value = ''
@@ -52,7 +60,11 @@ async function load() {
   }
 }
 
-onMounted(load)
+onMounted(() => {
+  load()
+  window.addEventListener('scroll', onScroll, { passive: true })
+})
+onBeforeUnmount(() => window.removeEventListener('scroll', onScroll))
 watch(() => route.params.slug, load)
 
 const isShort = computed(() => post.value && post.value.kind === 'short')
@@ -71,6 +83,8 @@ const initial = computed(() => (site.author_name || 'O').trim().slice(0, 1).toUp
   />
 
   <div v-else class="shell">
+    <!-- 阅读进度：贴在视口顶部的细线 -->
+    <div class="reading-bar" :style="{ width: progress + '%' }" aria-hidden="true"></div>
     <div class="layout">
       <!-- LeftNav / RightRail 之前 import 了却没渲染，导致整页掉进 236px 的左列。
            补上，和 HomeView 的三栏一致。 -->
@@ -146,7 +160,7 @@ const initial = computed(() => (site.author_name || 'O').trim().slice(0, 1).toUp
         <!-- 评论区（和 vivid 共用同一个组件，见 components/comments/） -->
         <CommentSection v-if="post" :post-id="post.id" />
       </main>
-      <RightRail />
+      <RightRail :toc="isShort ? [] : headings" />
     </div>
   </div>
 </template>