Dynamic shadow

Creates a shadow similar to box-shadow but based on the colors of the element itself.

• Use the ::after pseudo-element with position: absolute and width and height equal to 100% to fill the available space in the parent element.
• Use background: inherit to inherit the background of the parent element.
• Use top to slightly offset the pseudo-element, filter: blur() to create a shadow and opacity to make it semi-transparent.
• Use z-index: 1 on the parent and z-index: -1 on the pseudo-element to position it behind its parent.

<div class="dynamic-shadow"></div>

.dynamic-shadow {
  position: relative;
  width: 10rem;
  height: 10rem;
  background: linear-gradient(75deg, #6d78ff, #00ffb8);
  z-index: 1;
}

.dynamic-shadow::after {
  content: '';
  width: 100%;
  height: 100%;
  position: absolute;
  background: inherit;
  top: 0.5rem;
  filter: blur(0.4rem);
  opacity: 0.7;
  z-index: -1;
}