add less-loader

package.json

@@ -11,6 +11,8 @@
     "core-js": "^3.6.4",
     "element-ui": "^2.13.2",
     "file-saver": "^2.0.2",
+    "less": "^2.7.3",
+    "less-loader": "^6.1.0",
     "script-loader": "^0.7.2",
     "vue": "^2.6.11",
     "xlsx": "^0.16.1"

src/main.js

@@ -2,6 +2,7 @@ import Vue from 'vue'
 import App from './App.vue'
 import 'element-ui/lib/theme-chalk/index.css'
 import ElementUI from 'element-ui'
+import './../theme/theme.less'
 
 Vue.use(ElementUI)
 Vue.config.productionTip = false

src/views/Excel_Export.vue

@@ -35,6 +35,6 @@
     }
 </script>
 
-<style scoped>
+<style lang="less" scoped>
 
 </style>