CSS ::before and ::after for custom animations and transitions - LogRocket Blog
Using CSS transitions - CSS: Cascading Style Sheets | MDN
Josh W. Comeau on Twitter: "🎩🐇✨ If you want to animate an underline in CSS, it's common to use a box-shadow or pseudo-element. This super-fancy tutorial animates REAL underlines (`text-decoration`), via the
CSS】transition-delayの使い方、効果の開始時間を適用させる | SHU BLOG
18+ CSS Text Animations - csshint - A designer hub