Multiple CSS option for users [closed]

Answer 1

You can just disabled/enable the second stylesheet via the disabled property:

document.getElementById('css2').sheet.disabled = true;

or the whole element:

document.getElementById('css2').disabled = true;

That way the declarations will not overwrite the ones from the first. Your try of changing the href of the link would work as well, yet for that you would need only one tag that is switched between "css1.css" and "css2.css".