feat:资料云盘优化

src/bu-components/SelectPrepareFileModal.less

@@ -99,7 +99,7 @@
     }
 
     .footer__left {
-      color: #FF7519;
+      color: #5289fa;
       cursor: pointer;
     }
   }

src/modules/prepare-lesson/modal/SelectPrepareFileModal.less

@@ -103,7 +103,7 @@
     }
 
     .footer__left {
-      color: #FF7519;
+      color: #5289fa;
       cursor: pointer;
     }
   }