Access CSS variable from javascript

Use this:

window.getComputedStyle(document.documentElement).getPropertyValue('--color-font-general');

And you can change it like this:

document.documentElement.style.setProperty('--color-font-general', '#000');

source

Just the standard way:

1. Get the computed styles with getComputedStyle
2. Use getPropertyValue to get the value of the desired property

getComputedStyle(element).getPropertyValue('--color-font-general');

Example:

var style = getComputedStyle(document.body)
console.log( style.getPropertyValue('--bar') ) // #336699
console.log( style.getPropertyValue('--baz') ) // calc(2px*2)

:root { --foo:#336699; --bar:var(--foo); --baz:calc(2px*2); }