/* make the "snowflakes" outer DIV cover the entire screen */
.snowflakes {
  width: 100%;
  /* make taller than the screen so snowflakes go past bottom */
  height: 1700px;
  position: absolute;
  /* start above the top of the screen so the snowflakes don't "pop" in */
  top: -90px;
  left: 0;
  overflow: hidden;
  /* display underneath other DIVs */
  z-index: -1;
  /* can't select anything in the DIV */
  user-select: none;
}
/* color of individual snowflake italic tags, some variation
   colors should work on dark and light backgrounds */
.snowflakes i,
.snowflakes i:after,
.snowflakes i:before {
  background: #8C96EC;
}
.snowflakes i:nth-child(11n),
.snowflakes i:nth-child(11n):after,
.snowflakes i:nth-child(11n):before {
  background: #aea1c6;
}
.snowflakes i:nth-child(19n),
.snowflakes i:nth-child(19n):after,
.snowflakes i:nth-child(19n):before {
  background: #7aa3be;
}
/* apply the "snowflakes" animation to the italic tags */
.snowflakes i {
  display: inline-block;
  /* note the duration & timing for some of the flakes is overwritten below */
  animation: snowflakes 3s linear 2s 20;
  position: relative;
}
/* "before" and "after" pseudo-elements */
.snowflakes i:after,
.snowflakes i:before {
  /* make before and after pseudo-elements same size as element */
  height: 100%;
  width: 100%;
  /* give it some content so is visible and takes space */
  content: ".";
  position: absolute;
  top: 0px;
  left: 0px;
  /* rotate by 120 degrees (note "before" is overridden below) */
  transform: rotate(120deg);
}
/* rotate "before" by 240 degrees, so now we have an asterisk */
.snowflakes i:before {
  transform: rotate(240deg);
}
/* define animation: starts at top of page, ends at bottom following a wavy
   pattern; rotated 360 degrees; fades out at end */
@keyframes snowflakes {
  0% {
    transform: translate3d(0, 0, 0) rotate(0deg) scale(0.6);
    opacity: 1;
  }
  100% {
    transform: translate3d(15px, 1200px, 0) rotate(360deg) scale(0.6);
    opacity: 0;
  }
}
/* different size snowflakes, falling at different rates
   introduce some (almost) randomness using prime number spacing
   based on "Cicada principle"
   e.g. https://www.the215guys.com/learning/nth-child-cicada-principle/ */
.snowflakes i:nth-child(2n) {
  width: 16px;
  height: 4px;
  animation-duration: 5.1s;
  animation-iteration-count: 37;
  transform-origin: right -41px;
}
.snowflakes i:nth-child(3n) {
  width: 18px;
  height: 5px;
  animation-duration: 6.7s;
  animation-iteration-count: 11;
  transform-origin: right -29px;
}
.snowflakes i:nth-child(5n) {
  width: 24px;
  height: 6px;
  animation-duration: 8.3s;
  animation-iteration-count: 17;
  transform-origin: right -11px;
}
.snowflakes i:nth-child(11n) {
  width: 28px;
  height: 7px;
  animation-duration: 11.1s;
  animation-iteration-count: 13;
  transform-origin: right -19px;
}
.snowflakes i:nth-child(13n) {
  width: 32px;
  height: 8px;
  animation-duration: 13.7s;
  animation-iteration-count: 7;
  transform-origin: right -3px;
}
/* different delays so they don't all start at the same time, different opacity to make
   some look like they're behind others */
.snowflakes i:nth-child(2n+1) {
  opacity: 0.3;
  animation-delay: 0s;
  animation-timing-function: ease-in;
}
.snowflakes i:nth-child(3n+2) {
  opacity: 0.4;
  animation-delay: 0.7s;
  animation-timing-function: ease-out;
}
.snowflakes i:nth-child(5n+3) {
  opacity: 0.5;
  animation-delay: 1.3s;
  animation-timing-function: linear;
}
.snowflakes i:nth-child(7n+1) {
  opacity: 0.6;
  animation-delay: 2.1s;
  animation-timing-function: ease-in-out;
}
.snowflakes i:nth-child(11n+1) {
  opacity: 0.7;
  animation-delay: 2.7s;
  animation-timing-function: ease;
}
.snowflakes i:nth-child(13n+1) {
  opacity: 0.8;
  animation-delay: 3.1s;
}
.snowflakes i:nth-child(17n+1) {
  opacity: 0.9;
  animation-delay: 3.7s;
}