Animating <details> Element with Only CSS

This article provides a pure CSS solution for animating the opening and closing of the HTML <details> element, avoiding hacky approaches or JavaScript. It includes the complete CSS code using properties like block-size, overflow, transition-property, transition-behavior with allow-discrete, and calc-size(). The author breaks down each line of code, explaining how block-size animation works with content-visibility and discrete property transitions. The article also covers browser support and fallbacks for older browsers. It is a technical tutorial aimed at web developers looking for a clean, modern way to animate disclosure widgets.