CSS
Cascading Style Sheet (종속형 시트)
selector
https://www.w3schools.com/cssref/css_selectors.asp
미디어 쿼리
https://developer.mozilla.org/ko/docs/Web/CSS/CSS_media_queries/Using_media_queries
Cascading Style Sheet (종속형 시트)
https://www.w3schools.com/cssref/css_selectors.asp
https://developer.mozilla.org/ko/docs/Web/CSS/CSS_media_queries/Using_media_queries