next.js, css in js
yarn create next-app
yarn dev
yarn add typescript @types/react @types/node
header fixed menu
https://yoonsidae.tistory.com/35
dark mode
https://yeoulcoding.tistory.com/170
responsive
https://kim-mj.tistory.com/282
https://velog.io/@rjsdnql123/dd
https://www.howdy-mj.me/css/styled-components-with-global-style/
https://medium.com/styled-components/how-to-create-responsive-ui-with-styled-components-c6b71a3ce172