CSS Generators

.box {
  position: relative;
  transform-style: preserve-3d;
}
.box::before {
  content: "";
  position: absolute;	
  inset: 0px;
  background: conic-gradient(from 90deg at 40% -25%, #ffd700, #f79d03, #ee6907, #e6390a, #de0d0d, #d61039, #cf1261, #c71585, #cf1261, #d61039, #de0d0d, #ee6907, #f79d03, #ffd700, #ffd700, #ffd700);
  filter: blur(10px);
  transform: translate3d(0px,0px,-1px);
  clip-path: polygon(-100vmax -100vmax,100vmax -100vmax,100vmax 100vmax,-100vmax 100vmax,-100vmax -100vmax,0 0,0 100%,100% 100%,100% 0,0 0);
  pointer-events: none;
}