How to add conditional styles in emotion/react?

Question

I'm using react and emotion. I need to change the style of an element according to a boolean value. The below code does not work. How can I combine multiple styles correctly?

import { css } from "@emotion/react"

const navSticky = css({
  transform: "translateY(-10px)",
})
const navStyle = css({
  background: "red",
})

... 

 <nav css={isSticky ? {...navStyle, ...navSticky} : navStyle}> </nav>