_app.tsx

import type { AppProps } from "next/app";
import { createGlobalStyle } from "styled-components";

const GlobalStyle = createGlobalStyle`
  * {
    box-sizing: border-box;
    margin: 0px;
  }
`;

export default function MyApp({ Component, pageProps }: AppProps) {
  return (
    <>
      <GlobalStyle />
      <Component {...pageProps} />
    </>
  );
}