Standard CSS border-radius applies a uniform curve to container corners. However, using the advanced 8-value syntax separated by a forward slash (/), you can independently control horizontal and vertical radii to produce fluid, organic "blob" shapes that add visual energy to landing pages and UI headers.
/* Horizontal radii / Vertical radii */
border-radius: 42% 58% 70% 30% / 45% 45% 55% 55%;The four numbers before the slash represent the horizontal curves for each corner (top-left, top-right, bottom-right, bottom-left). The four numbers after the slash control the vertical curves for those same corners.
By transitioning between multiple 8-point configurations within a @keyframes animation, you can create smooth, perpetually morphing background graphics that bring your web apps to life without heavy video or canvas libraries.