A bleeding-edge CSS-in-JS library.

It supports all of the things: selectors, pseudo-classes, pseudo-elements, attributes, vendor prefixes, media queries and animations.

It also comes with custom features like extending and react hooks support.

Installation

npm install flcss

Usage

flcss will work with any framework that allows you to set class names.

import React from 'react';
import { createStyle } from 'flcss';

const Box = () => {
  return <div className={ styles.red }/>;
};

const styles = createStyle({
  red: {
    padding: '15px',
    backgroundColor: 'red'
  }
});

export default Box;

But also there's support to React hooks

import React, { useState } from 'react';

import { useStyles } from 'flcss/react';

const App = () => {
  const [ color, setColor ] = useState('red');

  const styles = useStyles({
    box: {
      padding: '15px',
      backgroundColor: color
    }
  });

  return <div className={ styles.box }/>;
}

Extending

const styles = createStyle({
  red: {
    padding: '15px',
    backgroundColor: 'red'
  },
  blue: {
    extend: 'red',
    backgroundColor: 'blue'
  }
});

Pseudo-classes and Pseudo-elements

const styles = createStyle({
  red: {
    padding: '15px',
    backgroundColor: 'red',

    ':hover': {
      backgroundColor: 'black',
    }
  }
});

const styles = createStyle({
  input: {
    fontSize: '12px',
    color: 'black',

    '::placeholder': {
      color: 'grey'
    }
  }
});

Media Queries

const styles = createStyle({
  red: {
    padding: '15px',
    backgroundColor: 'red',

    '@media screen and (max-width: 1080px)': {
      padding: '8px'
    }
  }
});

Attributes

const styles = createStyle({
  button: {
    padding: '15px',
    cursor: 'pointer',
    backgroundColor: 'black',

    '[enabled="false"]': {
      cursor: 'default',
      pointerEvents: 'none',
      backgroundColor: 'grey'
    }
  }
});

Child Selectors

const styles = createStyle({
  red: {
    padding: '15px',
    backgroundColor: 'red',

    '> div': {
      padding: '25px',
      backgroundColor: 'green',
    }
  }
});

Animations

const boxAnimation = createAnimation({
  keyframes: {
    from: {
      margin: '5px'
    },
    to: {
      margin: '10px'
    }
  },
  duration: '0.5s',
  timingFunction: 'cubic-bezier(0.18, 0.89, 0.32, 1.28)',
  fillMode: 'forwards',
  iterationCount: '1'
});

const styles = createStyle({
  box: {
    animation: boxAnimation
  }
})

const hoverAnimation = createAnimation({
  keyframes: {
    '0%': {
      transform: 'translateY(-10px)';
    },
    '50%': {
      transform: 'translateY(-5px)';
    },
    '100%': {
      transform: 'translateY(-10px)';
    }
  }
});

const floatAnimation = createAnimation({
  keyframes: {
    '100%': {
      transform: 'translateY(-10px)';
    }
  }
});

const styles = createStyle({
  box: {
      animationName: `${floatAnimation}, ${hoverAnimation}`,
      animationDuration: '.3s, 1.5s',
      animationDelay: '0s, .3s',
      animationTimingFunction: 'ease-out, ease-in-out',
      animationIterationCount: '1, infinite',
      animationFillMode: 'forwards',
      animationDirection: 'normal, alternate'
    }
  }
})

Basically, do anything you want, it will probably work, and if it didn't then open an issue and request it, and we'll add it.