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    1.1.7 • Public • Published


    📦 Svelte layout and grid system, heavily inspired by and largely ported from rebass/reflexbox for React 🙏.

    Downloads Version MIT License system-ui/theme

    • Primitive components for all your layout needs
    • Customize styles inline with the sx prop
    • Ergonomic responsive array-based values
    • Support for component variants
    • Styled System props
    • Themeable and compatible with the Theme Specification
    • Built with Styled System
    • Works with Theme UI
    • Built with Emotion

    Getting Started

    yarn add @svebass/flexbox
      import { Box, Flex } from '@svebass/flexbox';
    <Flex width={[ 1, 1/2]}>
      <Box p={2}>
        Box 1
      <Box p={2}>
        Box 2

    sx Prop

    The Box and Flex components both accept a sx prop that works with no additional setup required. The sx prop is similar to Emotion's css prop, but allows you to use values derived from the theme object.

    Flexbox follows the Theme Specification, which means that any theme created for use with Theme UI, Styled System, or other similar libraries will work out-of-the-box. This allows you to share design constraints for typography, color, and layout throughout your application using a theming context.

        p: 4,
        color: 'primary',

    Note: to opt-out of theme-based styles, use the css prop instead, which will not transform values.

    as Prop

    Passing an as prop and a tagname will convert the resulting container into the tag. Until dynamic tags are supported in Svelte, only a select few tags are supported:

    • div
    • button
    • a
    • img


    Because Flexbox follows the Theme Specification, all themes built for use with Styled System, Theme UI, or other related libraries are compatible with Flexbox.


    Adding a theme to your Svelte app is super simple with Svelte's context API.

    // Parent.svelte
      import { setContext } from 'svelte';
      import Child from './Child.svelte';
      const theme = {
        breakpoints: [
          '40em', '52em', '64em',
        colors: {
          text: '#000',
          background: '#fff',
          primary: '#07c',
        space: [
          0, 4, 8, 16, 32, 64, 128, 256,
      // Set context for children
      setContext('theme', theme);
    <Child />
    // Child.svelte
      import { Box, Flex } from '@svebass/flexbox';
        p: 4,
        bg: 'primary',


    You can also pass a theme directly as a prop:

      import { Box, Flex } from '@svebass/flexbox';
      import theme from './theme.js';
        p: 4,
        bg: 'primary',


    Flexbox components also accept a variant prop, which allows you to define commonly used styles, such as cards, badges, and CSS grid layouts, in your theme object for reuse.

    Add a variants object to your theme and include any variants as style objects. These styles can reference other values in your theme such as colors, typographic styles, and more.

    // example theme
    export default {
      colors: {
        text: '#000',
        background: '#fff',
        primary: '#07c',
      radii: {
        default: 4,
      shadows: {
        card: '0 0 4px rgba(0, 0, 0, .125)',
      variants: {
        card: {
          p: 3,
          borderRadius: 'default',
          bg: 'white',
          boxShadow: 'card',
        badge: {
          color: 'white',
          bg: 'primary',
          p: 1,
          borderRadius: 'default',

    To apply a variant to your component, pass the name to the variant prop.

    <Box variant='card'>Card</Box>
    <Box variant='badge'>Badge</Box>

    Responsive Styles

    Use array values to quickly and ergonomically add mobile-first responsive styles to specific properties. This works on all style props and the sx prop. See the Styled System docs for more.

    // 100% width at the smallest viewport width
    // 50% width at the next breakpoint
    // 25% width at the next breakpoint
    <Box width={[ '100%', '50%', '25%' ]} />

    You can customize the widths used for each breakpoint by defining a theme.breakpoints array in your theme.

    Styled System Props

    Flexbox conforms to the Theme Specification and includes many common Styled System props. The Box and Flex components accept the following props:

    Space Props

    Prop Theme Key
    margin, m space
    marginTop, mt space
    marginRight, mr space
    marginBottom, mb space
    marginLeft, ml space
    marginX, mx space
    marginY, my space
    padding, p space
    paddingTop, pt space
    paddingRight, pr space
    paddingBottom, pb space
    paddingLeft, pl space
    paddingX, px space
    paddingY, py space

    Layout Props

    Prop Theme Key
    width sizes
    height sizes
    minWidth sizes
    maxWidth sizes
    minHeight sizes
    maxHeight sizes

    Typography Props

    Prop Theme Key
    fontFamily fonts
    fontSize fontSizes
    fontWeight fontWeights
    lineHeight lineHeights
    letterSpacing letterSpacings
    fontStyle N/A
    textAlign N/A

    Color Props

    Prop Theme Key
    color colors
    backgroundColor, bg colors
    opacity N/A

    Flexbox Props

    Prop Theme Key
    alignItems N/A
    alignContent N/A
    justifyItems N/A
    justifyContent N/A
    flexWrap N/A
    flexDirection N/A
    flex N/A
    flexGrow N/A
    flexShrink N/A
    flexBasis N/A
    justifySelf N/A
    alignSelf N/A
    order N/A


    This library is the result of consolidating and porting APIs and ergonomics from RebassJS, Flexbox library, Grid Styled, and Rebass Grid.

    MIT License


    npm i @svebass/flexbox

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    43.3 kB

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    Last publish


    • tmarshall07