feat(StudyDetailPage): 添加滚动监听以更新活动标签

在StudyDetailPage组件中添加滚动监听，根据滚动位置动态更新活动标签。同时，在组件卸载时移除滚动监听以避免内存泄漏。

@@ -202,6 +202,22 @@ useTitle('学习详情');
 const topWrapperHeight = ref(0);
 const bottomWrapperHeight = ref(0);
 
+const handleScroll = () => {
+    const introElement = document.getElementById('intro');
+    const commentElement = document.getElementById('comment');
+    if (!introElement || !commentElement) return;
+
+    const scrollTop = window.scrollY;
+    const commentOffset = commentElement.offsetTop - parseInt(topWrapperHeight.value);
+
+    // 根据滚动位置更新activeTab
+    if (scrollTop >= commentOffset) {
+        activeTab.value = 'comments';
+    } else {
+        activeTab.value = 'intro';
+    }
+};
+
 onMounted(() => {
     nextTick(() => {
         const topWrapper = document.querySelector('.top-wrapper');
@@ -212,6 +228,9 @@ onMounted(() => {
         if (bottomWrapper) {
             bottomWrapperHeight.value = bottomWrapper.clientHeight + 'px';
         }
+
+        // 添加滚动监听
+        window.addEventListener('scroll', handleScroll);
     })
     const courseId = route.params.id;
     if (courseId) {
@@ -269,6 +288,11 @@ const handleTabChange = (name) => {
 };
 
 
+// 在组件卸载时移除滚动监听
+onUnmounted(() => {
+    window.removeEventListener('scroll', handleScroll);
+});
+
 </script>
 
 <style lang="less" scoped>