.gallery .board ์์ 43.2% ๊ณ์ฐ๋ฐฉ๋ฒ.
223(์ด๋ฏธ์งํ๋์ ๋์ด) + 223(์ด๋ฏธ์งํ๋์ ๋์ด) + 20(margin-left) + 10(margin-left) = 476
476/1100*100 = 43.2727%
::before padding-top ๋ถ๋ถ
(๋์ด/๋์ด)*100 ===> ํฐ ์ด๋ฏธ์ง ๊ธฐ์ค.
220321 ์ถ๊ฐ
height / width * 100 = padding-bottom
[CSS] selector { width: 100%; padding-bottom: ๊ณ์ฐ๊ฐ; background-size: 100%; }
์ถ์ฒ https://5603.tistory.com/135