perf: improve the dark theme

packages/@core/shared/constants/src/global.ts

@@ -1,15 +1,12 @@
-// --vben-content-client-height
-
-/**
- * @zh_CN CSS 变量前缀
- * @en_US CSS variable prefix
- */
-const CSS_VARIABLE_PREFIX = '--vben';
-
 /**
  * @zh_CN 布局内容高度 css变量
  * @en_US Layout content height
  */
-const CSS_VARIABLE_LAYOUT_CONTENT_HEIGHT = `${CSS_VARIABLE_PREFIX}-content-height`;
+const CSS_VARIABLE_LAYOUT_CONTENT_HEIGHT = `--vben-content-height`;
 
-export { CSS_VARIABLE_LAYOUT_CONTENT_HEIGHT, CSS_VARIABLE_PREFIX };
+/**
+ * @zh_CN 默认命名空间
+ */
+const DEFAULT_NAMESPACE = 'vben';
+
+export { CSS_VARIABLE_LAYOUT_CONTENT_HEIGHT, DEFAULT_NAMESPACE };