function check(tab) { const tabs = tab.split('/') let path = 'tab' for (tab of tabs) { path = `${path}/${tab}` document.getElementById(path).checked = true } } function push(tab) { window.history.pushState(null, null, `?tab=${tab}`) } function update(id) { const tab = id.split('/').slice(1).join('/') push(tab) } function main() { let tab = (new URL(document.location)).searchParams.get('tab') if (tab) { check(tab) } else { tab = '1/1' check(tab) push(tab) } } function swap() { document.body.classList.toggle('dark') }