Try this cool effect that uses SVG Gaussian blur, a color matrix and color blend to make two circles join together like drops of liquid
Lucas Bebber is the originator of some of the most creative effects I’ve ever seen on the web. So much so I couldn’t resist
SVG filters have good support, but not all browsers support them being applied to regular DOM elements, notably Safari. However, they do work at least on Firefox and Chrome, even the Android version, and the filter degrades nicely if it doesn’t work. If you absolutely need the effect to work, consider using SVG elements instead of DOM elements.
Read more from the source: CSS-Tricks