add

demo/css/main.css

@@ -45,6 +45,6 @@
 body {
   background-color: #eff1f4;
 }
-body.bi-theme-dark {
+.bi-theme-dark body {
   background-color: #191B2B;
 }

demo/js/north.js

@@ -28,13 +28,13 @@ Demo.North = BI.inherit(BI.Widget, {
                         type: "bi.text_button",
                         text: "星空蓝",
                         handler: function () {
-                            $("body").removeClass("bi-theme-default").addClass("bi-theme-dark");
+                            $("html").removeClass("bi-theme-default").addClass("bi-theme-dark");
                         }
                     }, {
                         type: "bi.text_button",
                         text: "典雅白",
                         handler: function () {
-                            $("body").removeClass("bi-theme-dark").addClass("bi-theme-default");
+                            $("html").removeClass("bi-theme-dark").addClass("bi-theme-default");
                         }
                     }]
                 }

demo/less/main.less

@@ -58,6 +58,6 @@ body {
   background-color: @color-bi-background-normal;
 }
 
-body.bi-theme-dark {
+.bi-theme-dark body {
   background-color: @color-bi-background-normal-theme-dark;
 }

docs/demo.css

@@ -54,7 +54,7 @@
 body {
   background-color: #eff1f4;
 }
-body.bi-theme-dark {
+.bi-theme-dark body {
   background-color: #191B2B;
 }
 /****添加计算宽度的--运算符直接需要space****/

docs/demo.js

@@ -5585,13 +5585,13 @@ BI.shortcut("demo.main", Demo.Main);Demo.North = BI.inherit(BI.Widget, {
                         type: "bi.text_button",
                         text: "星空蓝",
                         handler: function () {
-                            $("body").removeClass("bi-theme-default").addClass("bi-theme-dark");
+                            $("html").removeClass("bi-theme-default").addClass("bi-theme-dark");
                         }
                     }, {
                         type: "bi.text_button",
                         text: "典雅白",
                         handler: function () {
-                            $("body").removeClass("bi-theme-dark").addClass("bi-theme-default");
+                            $("html").removeClass("bi-theme-dark").addClass("bi-theme-default");
                         }
                     }]
                 }