Custom properties for polka dots

file.js

CSS.registerProperty({
    name: '--dot-spacing',
    syntax: '<length>',
    initialValue: '20px',
    inherits: false
});
CSS.registerProperty({
    name: '--dot-fade-offset',
    syntax: '<percentage>',
    initialValue: '0%',
    inherits: false
});
CSS.registerProperty({
    name: '--dot-color',
    syntax: '<color>',
    initialValue: '#fff',
    inherits: false
});