fix:修改管理员添加学员-选择关卡居中问题

src/components/student/CommonStudent.vue

@@ -341,7 +341,7 @@
   </a-modal>
  -->
   <a-modal
-    style="padding: 0"
+    :style="{padding: 0,position: relative,right: - (screenWidth/2 - 660) + 'px',}"
     :closable="true"
     :visible="stageVisible"
     :footer="null"
@@ -560,6 +560,7 @@ const stuSelectKeys = ref([]);
 const orgSelectKeys = ref([]);
 const auditSelectKeys = ref([]);
 const screenHeight = ref(document.body.clientHeight);
+const screenWidth = ref(document.body.clientWidth);
 const stuRowSelection = computed(() => ({
   columnWidth: 20,
   selectedRowKeys: stuSelectKeys.value,