CSS3

https://www.youtube.com/watch?v=duWfUzXPgNc https://tpverstak.ru/flex-cheatsheet/ https://tproger.ru/translations/how-css-flexbox-works/

https://bootsnipp.com/snippets/2eEjz https://codepen.io/hynden/pen/qlsJy https://sweetalert2.github.io/