背景色兼容IE-9（3363）

src/css/knowledgeMap.less

@@ -7,6 +7,9 @@
         height: 40px;
         line-height: 40px;
         background-image: linear-gradient(to right, #5A8EEE , #7EABFF);
+       filter:progid:DXImageTransform.Microsoft.gradient(GradientType=1, startColorstr=#1471da,endColorstr=#1C85FB);/*IE<9>*/
+        -ms-filter:"progid:DXImageTransform.Microsoft.gradient(GradientType=1, startColorstr=#1471da, endColorstr=#1C85FB)";/*IE8+*/
+
     }
     .titleTxt{
         position: relative;

src/css/knowledgeTree.less

@@ -5,6 +5,8 @@
         height: 40px;
         line-height: 40px;
         background-image: linear-gradient(to right, #5A8EEE , #7EABFF);
+        filter:progid:DXImageTransform.Microsoft.gradient(GradientType=1, startColorstr=#1471da,endColorstr=#1C85FB);/*IE<9>*/
+        -ms-filter:"progid:DXImageTransform.Microsoft.gradient(GradientType=1, startColorstr=#1471da, endColorstr=#1C85FB)";/*IE8+*/
     }
     .titleTxt{
         position: relative;