I have a simple app and I just want to setup a simple theme change functionality.
When using react + vite, I just used a script like this

const html = document.querySelector("html");
document.addEventListener("DOMContentLoaded", () => {
  const theme = localStorage.getItem("theme") ?? "cyberpunk";
  html.setAttribute("data-theme", theme);
});

document.addEventListener("theme-changed", (e) => {
  console.log(e.detail);
  const themeName = e.detail;
  html.setAttribute("data-theme", themeName);
})

How can I attach a script like that to a nextjs app?