Build Glassmorphic Card Designs with CSS Build glassmorphic card designs with backdrop blur, transparency, and shadow controls.

Glassmorphism relies on the backdrop-filter CSS property, which applies graphical effects to the area behind an element. The key function is blur(), which creates the frosted glass appearance. Combined with a semi-transparent background (using rgba or hsla), the effect allows content behind the card to be visible but blurred. The border uses a slightly higher opacity than the background for definition. The -webkit-backdrop-filter prefix is required for Safari support. For the effect to work, the element must have a transparent or semi-transparent background, and there must be content behind it to blur. Performance consideration: backdrop-filter can be expensive on large elements or when many blurred elements overlap. Use will-change: backdrop-filter to hint the browser about the animated property. For fallback, provide a solid semi-transparent background for browsers that do not support backdrop-filter.