[JS] Browser & Screen size

[출처] https://lookingfor.tistory.com/entry/%EC%9E%90%EB%B0%94%EC%8A%A4%ED%81%AC%EB%A6%BD%ED%8A%B8-%ED%99%94%EB%A9%B4-%ED%81%AC%EA%B8%B0-%EA%B5%AC%ED%95%98%EA%B8%B0