feat: dark mode

Vben

2021-04-07 5b8eb4a49a097a47caf491c44df427522ab58daa

 src/views/demo/permission/front/Btn.vue

@@ -86,6 +86,6 @@
</script>
<style lang="less" scoped>
  .demo {
    background: #fff;
    background: @component-background;
  }
</style>