message: Separates out box mixin
diff: -import styled from 'styled-components';
  +import styled, { css } from 'styled-components';
  import {
  display,
  space,
  @@ -15,7 +15,7 @@ import {
  bgColor,
  } from 'styled-system';
  -export default styled.div`
  +export const mixin = css`
  box-sizing: border-box;
  ${display}
  ${width}
  @@ -31,3 +31,7 @@ export default styled.div`
  ${borderRadius}
  ${bgColor}
  `;
  +
  +export default styled.div`
  + ${mixin}
  +`;
  