message: fix(styled-system): handle negative nums for css vars
diff: -import { StringOrNumber, isString, isNumber } from "@chakra-ui/utils"
  +import { StringOrNumber, isString, isNumber, isCssVar } from "@chakra-ui/utils"
  import unit from "./get-unit"
  const startsWith = (string: string, target: string) =>
  @@ -17,7 +17,7 @@ export function positiveOrNegative(
  if (startsWith(valueString, "-")) {
  const raw = scale[valueString.slice(1)]
  if (isString(raw)) {
  - result = `-${raw}`
  + result = isCssVar(raw) ? `calc(${raw} * -1)` : `-${raw}`
  } else if (isNumber(raw)) {
  result = raw * -1
  } else {
  