const button = document.getElementById("theme"); const classes = document.documentElement.classList; function button_refresh() { button.innerHTML = theme_get(); } function theme_get() { return classes.contains("dark")?"dark":"light"; } function theme_read() { const theme = localStorage.getItem("theme"); if (theme) { theme_set(theme); } } function theme_set(theme) { if (theme == "dark") { classes.add("dark"); } button_refresh(); } function theme_toggle() { classes.toggle("dark"); button_refresh(); theme_write(); } function theme_write() { localStorage.setItem("theme", theme_get()); } button.addEventListener("click", () => { theme_toggle(); }); theme_read();