CSS border


### Example
> [Creating an interactive spotlight border with CSS and React](https://www.julienthibeaut.xyz/blog/create-spotlight-border-with-react-css)

> [Button with rotating gradient border](https://t.co/BSPNWcadgH)



### border is margin box shadow is padding
> [[publishing] css inner border 만들기](https://jintrue.tistory.com/entry/publishing-css-inner-border-%EB%A7%8C%EB%93%A4%EA%B8%B0)

> [Fantastic CSS border animation](https://dev.to/chokcoco/fantastic-css-border-animation-5166?utm_source=tldrnewsletter)






