Cascading Style Sheets (CSS)

One Line Layouts (opens in a new tab)

Una Kravets (opens in a new tab) is a CSS Wizard working in developer relations for Google focused on Chrome. Here article https://web.dev/one-line-layouts/ (opens in a new tab) is a great intro to the power of CSS.

Grid (opens in a new tab)

display: grid is often what you want, check out https://css-tricks.com/snippets/css/complete-guide-grid/ (opens in a new tab) and https://learncssgrid.com/ (opens in a new tab)

Animista (opens in a new tab)

An on-demand CSS animations library