diff --git a/frontend/src/components/activity/activity.module.less b/frontend/src/components/activity/activity.module.less
index da7030b..6ea42f0 100644
--- a/frontend/src/components/activity/activity.module.less
+++ b/frontend/src/components/activity/activity.module.less
@@ -173,6 +173,60 @@
   }
 }
 
+.activityTitle {
+  font-size: 28px;
+  margin-bottom: 16px;
+  color: #fff;
+  line-height: 1.3;
+
+  @media (max-width: 768px) {
+    font-size: 22px;
+    margin-bottom: 12px;
+  }
+}
+
+.metaInfo {
+  display: flex;
+  gap: 20px;
+  margin-bottom: 16px;
+  color: rgba(255, 255, 255, 0.7);
+  flex-wrap: wrap;
+
+  @media (max-width: 768px) {
+    gap: 12px;
+    margin-bottom: 12px;
+  }
+}
+
+.metaItem {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 14px;
+
+  @media (max-width: 768px) {
+    font-size: 13px;
+    gap: 6px;
+    background: rgba(255, 255, 255, 0.05);
+    padding: 4px 8px;
+    border-radius: 4px;
+  }
+}
+
+.statusWrapper {
+  display: flex;
+  gap: 10px;
+}
+
+.headerGradient {
+  position: absolute;
+  bottom: 0;
+  left: 0;
+  width: 100%;
+  height: 50%;
+  background: linear-gradient(to top, #1f1f1f, transparent);
+}
+
 .time {
   color: var(--text-secondary);
   font-size: 14px;
@@ -188,6 +242,11 @@
   min-height: 300px;
   width: 100%;
   overflow: hidden;
+
+  @media (max-width: 768px) {
+    height: 40vh;
+    min-height: 250px;
+  }
 }
 
 .detailImage {
@@ -202,6 +261,11 @@
   position: relative;
   z-index: 10;
   padding: 0 var(--spacing-lg) 100px; /* Bottom padding for fixed footer */
+
+  @media (max-width: 768px) {
+    padding: 0 var(--spacing-md) 80px;
+    margin-top: -40px;
+  }
 }
 
 .infoCard {
@@ -211,6 +275,11 @@
   box-shadow: var(--box-shadow-base);
   margin-bottom: var(--spacing-lg);
   border: 1px solid var(--border-color);
+
+  @media (max-width: 768px) {
+    padding: var(--spacing-md);
+    margin-bottom: var(--spacing-md);
+  }
 }
 
 .richText {
@@ -218,6 +287,10 @@
   line-height: 1.8;
   font-size: 16px;
   
+  @media (max-width: 768px) {
+    font-size: 15px;
+  }
+  
   img {
     max-width: 100%;
     border-radius: var(--border-radius-base);
@@ -227,6 +300,11 @@
   h1, h2, h3 {
     color: var(--text-primary);
     margin-top: var(--spacing-lg);
+    
+    @media (max-width: 768px) {
+      margin-top: var(--spacing-md);
+      font-size: 1.2em; /* slightly smaller headings */
+    }
   }
 }
 
diff --git a/frontend/src/pages/activity/Detail.jsx b/frontend/src/pages/activity/Detail.jsx
index 64d2a57..a26395a 100644
--- a/frontend/src/pages/activity/Detail.jsx
+++ b/frontend/src/pages/activity/Detail.jsx
@@ -37,7 +37,7 @@ const ActivityDetail = () => {
   const headerColor = useTransform(scrollY, [0, 60], ['rgba(255,255,255,1)', 'rgba(0,0,0,0.85)']);
   const titleOpacity = useTransform(scrollY, [100, 200], [0, 1]);
 
-  const { data: activity, isLoading, error, refetch } = useQuery({
+  const { data: activity, isLoading, error } = useQuery({
     queryKey: ['activity', id],
     queryFn: async () => {
       try {
@@ -140,7 +140,7 @@ const ActivityDetail = () => {
              
              clearInterval(timer);
           }
-        } catch (error) {
+        } catch {
           // ignore error during polling
         }
       }, 3000);
@@ -188,7 +188,7 @@ const ActivityDetail = () => {
           text: '来看看这个精彩活动！',
           url: url
         });
-      } catch (err) {
+      } catch {
         console.log('Share canceled');
       }
     } else {
@@ -256,6 +256,23 @@ const ActivityDetail = () => {
     );
   }
 
+  if (!activity) {
+    return (
+      <div style={{ padding: 40, background: '#1f1f1f', minHeight: '100vh', display: 'flex', justifyContent: 'center', alignItems: 'center' }}>
+        <Result
+          status="404"
+          title="活动未找到"
+          subTitle="抱歉，该活动可能已被删除或不存在。"
+          extra={[
+            <Button type="primary" key="back" onClick={() => navigate(-1)}>
+              返回列表
+            </Button>
+          ]}
+        />
+      </div>
+    );
+  }
+
   const cleanUrl = (url) => {
     if (!url) return '';
     return url.replace(/[`\s]/g, '');
@@ -313,45 +330,38 @@ const ActivityDetail = () => {
           alt={activity.title}
           className={styles.detailImage}
         />
-        <div style={{
-            position: 'absolute',
-            bottom: 0,
-            left: 0,
-            width: '100%',
-            height: '50%',
-            background: 'linear-gradient(to top, #1f1f1f, transparent)'
-        }} />
+        <div className={styles.headerGradient} />
       </div>
 
       {/* Content */}
       <div className={styles.detailContent}>
         <div className={styles.infoCard}>
-          <h1 style={{ fontSize: 28, marginBottom: 16, color: '#fff' }}>{activity.title}</h1>
+          <h1 className={styles.activityTitle}>{activity.title}</h1>
           
-          <div style={{ display: 'flex', gap: 20, marginBottom: 16, color: 'rgba(255,255,255,0.7)' }}>
-             <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+          <div className={styles.metaInfo}>
+             <div className={styles.metaItem}>
                <CalendarOutlined />
                <span>{activity.start_time ? new Date(activity.start_time).toLocaleDateString() : 'TBD'}</span>
              </div>
-             <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+             <div className={styles.metaItem}>
                <ClockCircleOutlined />
                <span>{activity.start_time ? new Date(activity.start_time).toLocaleTimeString() : 'TBD'}</span>
              </div>
-             <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+             <div className={styles.metaItem}>
                <EnvironmentOutlined />
                <span>{activity.location || '线上活动'}</span>
              </div>
-             <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+             <div className={styles.metaItem}>
                <UserOutlined />
                <span>{activity.current_signups || 0} / {activity.max_participants} 已报名</span>
              </div>
-             <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+             <div className={styles.metaItem}>
                <PayCircleOutlined />
                <span>{activity.is_paid ? `¥${activity.price}` : '免费'}</span>
              </div>
           </div>
           
-          <div style={{ display: 'flex', gap: 10 }}>
+          <div className={styles.statusWrapper}>
             <span className={styles.statusTag}>
               {activity.status || (new Date() < new Date(activity.start_time) ? '报名中' : '已结束')}
             </span>
@@ -365,7 +375,7 @@ const ActivityDetail = () => {
                 remarkPlugins={[remarkGfm]}
                 rehypePlugins={[rehypeRaw]}
                 components={{
-                  code({node, inline, className, children, ...props}) {
+                  code({inline, className, children, ...props}) {
                     const match = /language-(\w+)/.exec(className || '')
                     return !inline && match ? (
                       <SyntaxHighlighter