Design system utilities for styled-components, glamorous, and other css-in-js libraries

npm i styled-system

// With styled-components
import styled from 'styled-components'
import { space, width, fontSize, color } from 'styled-system'

const Box = styled.div`
  ${space}
  ${width}
  ${fontSize}
  ${color}
`

// Or with glamorous
import glamorous from 'glamorous'
import { space, width, fontSize, color } from 'styled-system'

const Box = glamorous.div(space, width, fontSize, color)

// width: 50%
<Box width={1/2} />

// font-size: 20px
<Box fontSize={4} />

// margin: 16px
<Box m={2} />

// padding: 32px
<Box p={3} />

// color
<Box color='tomato' />
<Box color='grays.0' />

// background color
<Box bg='tomato' />

// responsive width
<Box width={[ 1, 1/2, 1/4 ]} />

// responsive font-size
<Box fontSize={[ 2, 3, 4 ]} />

// responsive margin
<Box m={[ 1, 2, 3 ]} />

// responsive padding
<Box p={[ 1, 2, 3 ]} />

import { width } from 'styled-system'

The width utility parses a component's width prop and converts it into a CSS width declaration.

Numbers from 0-1 are converted to percentage widths. Numbers greater than 1 are converted to pixel values. String values are passed as raw CSS values. And arrays are converted to responsive width styles.

import { fontSize } from 'styled-system'

The fontSize utility parses a component's fontSize prop and converts it into a CSS font-size declaration. Numbers from 0-8 are converted to values on the font size scale. Numbers greater than 8 are converted to raw pixel values. String values are passed as raw CSS values. And array values are converted into responsive values.

import { space } from 'styled-system'

The space utility converts shorthand margin and padding props to margin and padding CSS declarations. Numbers from 0-4 are converted to values on the spacing scale. Negative values can be used for negative margins. Numbers greater than 4 are converted to raw pixel values. String values are converted passed as raw CSS values. And array values are converted into responsive values.

Margin and padding props follow a shorthand syntax for specifying direction.

• m: margin
• mt: margin-top
• mr: margin-right
• mb: margin-bottom
• ml: margin-left
• mx: margin-left and margin-right
• my: margin-top and margin-bottom
• p: padding
• pt: padding-top
• pr: padding-right
• pb: padding-bottom
• pl: padding-left
• px: padding-left and padding-right
• py: padding-top and padding-bottom

import { color } from 'styled-system'

The color utility parses a component's color and bg props and converts them into CSS declarations. By default the raw value of the prop is returned. Color palettes can be configured with the ThemeProvider to use keys as prop values, with support for dot notation. Array values are converted into responsive values.

All props accept arrays as values for mobile-first responsive styles.

// 100% below the smallest breakpoint,
// 50% from the next breakpoint and up,
// and 25% from the next breakpoint and up
<Box w={[ 1, 1/2, 1/4 ]} />

// responsive font size
<Box fontSize={[ 1, 2, 3, 4 ]} />

// responsive margin
<Box m={[ 1, 2, 3, 4 ]} />

// responsive padding
<Box p={[ 1, 2, 3, 4 ]} />

The responsiveStyle utility can be used to handle array-based responsive style props for other CSS properties.

import styled from 'styled-components'
import { responsiveStyle } from 'styled-system'

// Usage
// responsiveStyle(cssProperty[, propName][, booleanValue])

const Flex = styled.div`
  display: flex;
  ${responsiveStyle('flex-direction', 'direction')}
`

const App = props => (
  <Flex direction={[ 'column', 'row' ]}>
    <div>Responsive</div>
    <div>Direction</div>
  </Flex>
)

Styled-components attempts to remove invalid HTML attributes from props, but does not remove width, fontSize, or color. When using styled-system with other CSS-in-JS libraries, it can also be helpful to remove style props. To ensure style props are not passed to the element, a removeProps utility can be used.

import React from 'react'
import styled from 'styled-components'
import {
  width,
  fontSize,
  space,
  removeProps
} from 'styled-system'

const BaseComponent = props => {
  const next = removeProps(props)
  return <div {...next} />
}

const Component = styled(BaseComponent)([],
  width,
  fontSize,
  space
)

styled-system uses a mobile-first responsive approach, where any value set works from that breakpoint and wider. The default set of breakpoints aims to cover a wide range of devices from mobile to desktop. Breakpoints can be customized using styled-components' ThemeProvider.

[ 40, 52, 64 ]
// @media screen and (min-width: 40em)
// @media screen and (min-width: 52em)
// @media screen and (min-width: 64em)

Using a typographic scale helps create visual rhythm and reduces the number of decisions needed when designing UI. Styled system uses a modular scale that covers most of a UI's needs, but it can be customized with styled-components' ThemeProvider.

[ 12, 14, 16, 20, 24, 32, 48, 64, 72 ]

Using a scale for spacing helps ensure elements line up, even when nested inside one another. styled-system uses a spacing scale based on an 8px, powers-of-two grid for margin and padding by default and can be customized with styled-components' ThemeProvider.

[ 0, 8, 16, 32, 64 ]

styled-system can be configured with styled-components' ThemeProvider

import { ThemeProvider } from 'styled-components'
// or import { ThemeProvider } from 'glamorous'
import MyComponent from './MyComponent'

const theme = {
  breakpoints: [
    32, 48, 64
  ],
  space: [
    0, 6, 12, 18, 24
  ],
  fontSizes: [
    12, 16, 18, 24, 36, 72
  ],
  colors: {
    black: '#111',
    blue: '#07c',
  }
}

const App = props => (
  <ThemeProvider theme={theme}>
    <MyComponent
      fontSize={4}
      my={[ 2, 3 ]}
      color='blue'
    />
  </ThemeProvider>
)

• grid-styled
• Rebass
• styled-components
• glamorous

MIT License