HTML/CSS box-sizing
box-sizing: border-box;
paddingとborderを含める
box-sizing: content-box;
paddingとborderを含めない
box-sizing: inherit;
親要素のborder-boxを引き継ぐ
//参考URL
https://saruwakakun.com/html-css/reference/box-sizing
box-sizing: border-box;
paddingとborderを含める
box-sizing: content-box;
paddingとborderを含めない
box-sizing: inherit;
親要素のborder-boxを引き継ぐ
//参考URL
https://saruwakakun.com/html-css/reference/box-sizing