wasser

Fluid CSS properties

Create highly responsive and still pixel-perfect websites.

Tip

A successor JavaScript-only library called optica has been released. It requires the clamp() CSS math function but no longer needs any breakpoints.

Use Cases

Best suited when you have a desktop and a mobile design of the site. Wasser will allow you to implement the design pixel perfect on both of these viewports. In between you get a linearly scaling design without any effort. If you only have a design of the desktop version you get the mobile version for free.

CSS-in-JS, SASS or LESS?

Below the CSS-in-JS version is documented. Please refer to the following documentations if you prefer SASS or LESS:

• SASS Documentation
• LESS Documentation

The CSS-in-JS version is newer and requires CSS Variables (no IE11). Both the SASS and LESS version also work with older browsers.

Installation and Usage

npm i wasser

import React from 'react'
import { render } from 'react-dom'
import { styled, globalCss } from '@stitches/react'
import { wasser, globalVariables, fontObject } from 'wasser'

globalCss(globalVariables())()

const Wrapper = styled('div', {
  padding: wasser(50),
})

const Heading = styled('h1', {
  ...fontObject(50),
})

render(
  <Wrapper>
    <Heading>Scalable Properties</Heading>
  </Wrapper>,
  document.body,
)

Usage with @emotion

Click to show usage with @emotion!

import React from 'react'
import { render } from 'react-dom'
import { Global, css } from '@emotion/core'
import styled from '@emotion/styled'
import { wasser, font, head } from 'wasser'

const Wrapper: any = styled.div`
  padding: ${wasser(50)};
`

const Heading: any = styled('h1')`
  ${font(50)}
`

render(
  <Wrapper>
    <Global styles={css(head())} />
    <Heading>Scalable Properties</Heading>
  </Wrapper>,
  document.body
)

How it works

Interface

wasser(max: number, [min]: number)

max will be the value at the upper breakpoint, while min will be the value at the lower breakpoint.

If min is missing, max divided by the scaling factor will be used.

.some-element {
  padding: ${wasser(20)};
}

const SomeElement = styled('div', {
  padding: wasser(20),
})

Fonts

font(max: number, [min]: number, [line-height-ratio]: number)

This call does not require a property as it will set both the font-size and the associated line-height. The line-height does not require a separate value since it is stretched by the configurable fontSizeToLineHeightRatio.

.some-text {
  ${font(16)}
}
// =>
.some-text {
  font-size: ...;
  line-height: ...;
}

const Heading = styled('h3', {
  ...fontObject(18),
})
// =>
const Heading = styled('h3', {
  fontSize: ...,
  lineHeight: ...,
})

Configuration

Call the configure function before rendering to change the default settings.

import { configure } from 'wasser'

configure({
  scalingRatio: 2,
})

The following variables are available and can be configured.

Variable	Default	Description
viewportMin	320	Minimum breakpoint
viewportMax	1500	Maximum breakpoint
scalingRatio	1.5	Ratio to calculate min from max when min is not explicitly set.
scalingRatioFont	1.2	Scaling ratio for font properties.
fontSizeToLineHeightRatio	1.5	Ratio to get line-height from font-size.