Typescript error with lighten and cssVar

• polished version:
• JSS-in_CSS library and version:
• Any relevant JS library and version:

Mixin/Helper/Shorthand Usage

What You Are Seeing

What You Expected To See

No typescript error while using lighten and cssVar together

Reproduction

React 17.0.1 Typescript: 4.1.2 Polished: 4.1.1 Styled-components: 5.1.5;