Update css type

Author: epilande

packages/css/src/index.ts

@@ -1,7 +1,4 @@
-import * as CSS from 'csstype'
-
-import { SystemStyleObject, UseThemeFunction, Theme } from './types'
-import { SerializedStyles } from '@emotion/serialize'
+import { CSSObject, SystemStyleObject, UseThemeFunction, Theme } from './types'
 
 export * from './types'
 
@@ -257,7 +254,7 @@ type CssPropsArgument = { theme: Theme } | Theme
 
 export const css = (args: SystemStyleObject = {}) => (
   props: CssPropsArgument = {}
-) => {
+): CSSObject => {
   const theme: Theme = {
     ...defaultTheme,
     ...('theme' in props ? props.theme : props),
@@ -298,5 +295,5 @@ export const css = (args: SystemStyleObject = {}) => (
     }
   }
 
-  return result as SerializedStyles
+  return result
 }