https://www.w3schools.com/css/css3_animations.asp
https://themeisle.com/blog/css-animations-tutorial/
https://www.lambdatest.com/blog/css-animations-tutorial/
https://blog.hubspot.com/website/css-animation-examples
Ejemplos:
https://1stwebdesigner.com/css-effects/
https://dev.to/afif/another-100-underline-overlay-animations-the-extended-css-collection-574c