```

fix(LearningSystem): 调整学习系统详情页面课程介绍样式

修改了课程介绍文本区域的上边距，从mt20调整为mt10，
使页面布局更加紧凑合理。
```

src/pages/LearningSystem/LearningSystemDetail.vue

@@ -20,7 +20,7 @@
             <el-button type="primary"  plain v-if="info.studyStageName">{{info.studyStageName}}</el-button>
             <el-button type="primary" plain v-if="info.courseCategoryName">{{info.courseCategoryName}}</el-button>
           </div>
-          <div class="gray font_size16 mt20 line5">
+          <div class="gray font_size16 mt10 line5">
             {{info.courseIntro}}
           </div>
         </div>