diff --git a/miniprogram/pages/category/category.js b/miniprogram/pages/category/category.js
index 0a046d8..124ffb4 100644
--- a/miniprogram/pages/category/category.js
+++ b/miniprogram/pages/category/category.js
@@ -51,9 +51,13 @@ Page({
     this.setData({ loading: true });
     const key = DIM_MAP[this.data.dimension] || 'body-parts';
     svc.getCategories(key).then((items) => {
+      const list = (items || []).slice();
+      // 头部插入「全部」项：无 value 入参时默认选中，明确当前为「全部」
+      list.unshift({ value: '', label: '全部' });
+      const activeValue = this.data.value || '';
       this.setData({
-        values: items || [],
-        activeValue: this.data.value,
+        values: list,
+        activeValue: activeValue,
         loading: false
       });
       this.loadExercises();
diff --git a/miniprogram/pages/category/category.wxml b/miniprogram/pages/category/category.wxml
index 17e8a70..10143c3 100644
--- a/miniprogram/pages/category/category.wxml
+++ b/miniprogram/pages/category/category.wxml
@@ -2,7 +2,7 @@
   <navbar title="{{title}}" show-back />
 
   <view class="section" style="padding-top: 8rpx;">
-    <scroll-view wx:if="{{values.length}}" scroll-x class="filterbar">
+    <scroll-view wx:if="{{values.length}}" scroll-x class="filterbar" style="top: calc({{statusBarHeight}}px + 88rpx);">
       <chip
         wx:for="{{values}}"
         wx:key="value"
@@ -12,6 +12,7 @@
         bind:select="onValue" />
       <view class="filterbar__spacer"></view>
     </scroll-view>
+    <view wx:else class="filterbar__loading muted">{{ loading ? '加载分类中…' : '暂无分类' }}</view>
 
     <view class="count muted" wx:if="{{!loading}}">共 {{total}} 个动作</view>
 
diff --git a/miniprogram/pages/category/category.wxss b/miniprogram/pages/category/category.wxss
index ae8a8dc..11fde5c 100644
--- a/miniprogram/pages/category/category.wxss
+++ b/miniprogram/pages/category/category.wxss
@@ -1,7 +1,20 @@
 .page { min-height: 100vh; background: var(--bg-grad); }
-.filterbar { white-space: nowrap; padding: 8rpx 0 4rpx; }
+/* 分类横列吸顶：top = 状态栏高度 + 导航栏 88rpx，精确贴在 navbar 下方，不同机型不串位 */
+.filterbar {
+  position: sticky;
+  z-index: 40;
+  white-space: nowrap;
+  padding: 8rpx 0 4rpx;
+  background: var(--bg-grad);
+}
 .filterbar chip { display: inline-block; margin-right: 16rpx; }
 .filterbar__spacer { display: inline-block; width: 4rpx; }
+/* 加载 / 空态占位：横列区域常驻，避免加载期间整块消失 */
+.filterbar__loading {
+  font-size: 24rpx;
+  padding: 22rpx 4rpx 14rpx;
+  background: var(--bg-grad);
+}
 .count { font-size: 24rpx; margin: 20rpx 0 8rpx; }
 .grid { display: flex; flex-wrap: wrap; gap: 18rpx; margin-top: 12rpx; }
 .grid__item { width: calc((100% - 18rpx) / 2); }