Glassmorphism in CSS: The Frosted Glass Effect Done Right

Glassmorphism is the frosted glass effect that took over UI design around 2020-2021. Apple uses it extensively in macOS and iOS. Windows uses it in their Fluent Design system. And when done well, it creates a sense of depth and hierarchy that flat design cannot match. The effect relies on three CSS properties working together: backdrop-filter for the blur, a semi-transparent background, and a subtle border. Getting the balance right between these three is the difference between "elegant frosted glass" and "illegible mess." The core CSS .glass-card { background : rgba ( 255 , 255 , 255 , 0.15 ); backdrop-filter : blur ( 12px ); -webkit-backdrop-filter : blur ( 12px ); border : 1px solid rgba ( 255 , 255 , 255 , 0.2 ); border-radius : 16px ; box-shadow : 0 8px 32px rgba ( 0 , 0 , 0 , 0.1 ); } Each property serves a specific purpose: backdrop-filter: blur(12px) applies a Gaussian blur to everything behind the element. The blur radius controls the "frosted" intensity. 4-8px gives a subtle