website/pages/_app.tsx

import { useEffect } from "react"
import type { AppType } from "next/app"
import { ThemeProvider } from "next-themes"
import useTranslation from "next-translate/useTranslation"

import "../styles/global.css"

import "@fontsource/montserrat/400.css"
import "@fontsource/montserrat/500.css"
import "@fontsource/montserrat/600.css"
import "@fontsource/montserrat/700.css"

import "@fontsource/roboto/400.css"
import "@fontsource/roboto/700.css"

import { cookies } from "../tools/cookies"

const Application: AppType = ({ Component, pageProps }) => {
  const { lang } = useTranslation()

  useEffect(() => {
    cookies.set("NEXT_LOCALE", lang)
    const appHeight = (): void => {
      document.documentElement.style.setProperty(
        "--app-height",
        `${window.innerHeight}px`,
      )
    }
    window.addEventListener("resize", appHeight)
    appHeight()
    return () => {
      window.removeEventListener("resize", appHeight)
    }
  }, [lang])

  return (
    <ThemeProvider attribute="class" defaultTheme="dark">
      <Component {...pageProps} />
    </ThemeProvider>
  )
}

export default Application