```

feat(LearnNote): 优化学习笔记页面样式和布局

- 添加mb10类名以增加底部间距
- 移除课程列表项的mt10类名，统一间距样式
- 调整课程介绍文本样式，从line2改为line1并减少上边距
- 修改立即学习按钮的上边距为mt5
- 更新容器最大高度计算方式，从calc(100% - 100px)改为calc(100vh - 120px)
- 添加overflow-y: auto实现垂直滚动
```

src/pages/LearnNote/LearnNote.vue

@@ -4,11 +4,11 @@
     <div class="flex-between">
       <div class="detail_right">
         <div class="padding16 bg_color_fff border_radius_10 box_shadow_card">
-          <div class="gap10">
+          <div class="gap10 mb10">
             <div class="line_vertical"></div>
             <div class="font_size20 bold">{{$t('common.learnNoteList')}} </div>
           </div>
-          <div class="flex-between mt10 course_List cursor-pointer" 
+          <div class="flex-between course_List cursor-pointer" 
           @click="selectedItem = item"
           :class="{'active': item.courseId === selectedItem.courseId}"
           v-for="item in list" :key="item.courseId">
@@ -17,8 +17,8 @@
             </div>
             <div class="flex_1 ml20">
               <div class="font_size18 bold">{{ item.courseTitle }}</div>
-              <div class="font_size14 line2 gray mt10">{{ item.courseIntro }}</div>
-              <div class="flex-center-flex-end mt10" v-if="item.courseId!=-1">
+              <div class="font_size14 line1 gray mt5">{{ item.courseIntro }}</div>
+              <div class="flex-center-flex-end mt5" v-if="item.courseId!=-1">
                 <div class="gap5 gradient border_radius_4 cursor-pointer xuexi" @click.stop.prevent="goDetail(item)">
                   <img :src="playIcon" alt="" style="width:13px;height:15px">
                   <div>{{$t('common.lijixuexi')}}</div>
@@ -108,7 +108,8 @@ const goDetail = (item) => {
 <style lang="scss">
 .LearnNote{
   .detail_right{
-    max-height: calc(100% - 100px);
+    max-height: calc(100vh - 120px);
+    overflow-y: auto;
   }
   .course_List{
     padding: 16px;