Liquid Glass Navbar:

themeBtn.addEventListener("click", () => {
    const root = document.documentElement;
    const isDark = root.getAttribute("data-theme") === "dark";

    root.setAttribute(
        "data-theme",
        isDark ? "light" : "dark"
    );

    setTimeout(() => {
        const active = document.querySelector(".nav-btn.active");
        if (active) updatePill(active);
    }, 100);
});