.hourglass,
.hourglass:before,
.hourglass:after {
  animation-duration: 10s;
  animation-iteration-count: infinite;
}
.hourglass {
  --scale: 1;
  --bg: #e3e4e8;
  --fg: white;
  --primary: rgb(36, 173, 156);
  --polygonH: polygon(
    0% 0%,
    100% 0%,
    100% 5.55%,
    95% 5.55%,
    95% 28%,
    60% 46%,
    60% 54%,
    95% 72%,
    95% 94.45%,
    100% 94.45%,
    100% 100%,
    0% 100%,
    0% 94.45%,
    5% 94.45%,
    5% 72%,
    40% 54%,
    40% 46%,
    5% 28%,
    5% 5.55%,
    0% 5.55%
  );
  animation-name: flip;
  animation-timing-function: ease-in-out;
  background-image: linear-gradient(var(--primary) 0.5em, #737a8c55 0.5em 8.5em, var(--primary) 8.5em);
  clip-path: var(--polygonH);
  -webkit-clip-path: var(--polygonH);
  overflow: hidden;
  position: relative;
  width: calc(5em * var(--scale));
  height: calc(9em * var(--scale));
  z-index: 0;
}
.hourglass:before,
.hourglass:after {
  animation-timing-function: linear;
  content: "";
  display: block;
  position: absolute;
}

.hourglass:before {
  animation-name: fill;
  background-color: var(--fg);
  background-size: 100% calc(3.6em * var(--scale));
  clip-path: var(--polygonB1);
  -webkit-clip-path: var(--polygonB1);
  top: calc(0.5em * var(--scale));
  left: calc(0.5em * var(--scale));
  width: calc(4em * var(--scale));
  height: calc(8em * var(--scale));
  z-index: 1;
}

.hourglass:after {
  animation-name: glare;
  background-repeat: repeat-x;
  top: 0;
  left: calc(-3em * var(--scale));
  width: 200%;
  height: 100%;
  z-index: 2;
}

.hourglass:before {
  --polygonB1: polygon(
    0% 0%,
    100% 0%,
    100% 24%,
    50% 47%,
    50% 47%,
    50% 47%,
    50% 47%,
    50% 47%,
    50% 47%,
    50% 47%,
    50% 47%,
    0% 24%
  );
  --polygonB2: polygon(
    0% 4%,
    100% 4%,
    100% 24%,
    55% 45%,
    55% 100%,
    55% 100%,
    55% 100%,
    45% 100%,
    45% 100%,
    45% 100%,
    45% 45%,
    0% 24%
  );
  --polygonB3: polygon(
    0% 24%,
    100% 24%,
    100% 24%,
    55% 45%,
    55% 80%,
    100% 100%,
    100% 100%,
    0% 100%,
    0% 100%,
    45% 80%,
    45% 45%,
    0% 24%
  );
  --polygonB4: polygon(
    45% 45%,
    55% 45%,
    55% 45%,
    55% 45%,
    55% 58%,
    100% 76%,
    100% 100%,
    0% 100%,
    0% 76%,
    45% 58%,
    45% 45%,
    45% 45%
  );
  --polygonB5: polygon(
    50% 53%,
    50% 53%,
    50% 53%,
    50% 53%,
    50% 53%,
    100% 76%,
    100% 100%,
    0% 100%,
    0% 76%,
    50% 53%,
    50% 53%,
    50% 53%
  );
  animation-name: fill;
  background-color: var(--fg);
  background-size: 100% 3.6em;
  clip-path: var(--polygonB1);
  -webkit-clip-path: var(--polygonB1);
  top: 0.5em;
  left: 0.5em;
  width: 4em;
  height: 8em;
  z-index: 1;
}
.hourglass:after {
  animation-name: glare;
  background: linear-gradient(
        90deg,
        #0000 0.5em,
        #0003 0.5em 1.5em,
        #0000 1.5em 3.5em,
        #fff3 3.5em 4.5em,
        #fff0 4.5em 6.5em,
        #0003 6.5em 7.5em,
        #0000 7.5em
      )
      0 0 / 100% 0.5em,
    linear-gradient(
        90deg,
        #0000 0.75em,
        #0003 0.75em 1.25em,
        #0000 1.25em 3.75em,
        #fff3 3.75em 4.25em,
        #fff0 4.25em 6.75em,
        #0003 6.75em 7.25em,
        #0000 7.25em
      )
      0 0.5em / 100% 8em,
    linear-gradient(
        90deg,
        #0000 0.5em,
        #0003 0.5em 1.5em,
        #0000 1.5em 3.5em,
        #fff3 3.5em 4.5em,
        #fff0 4.5em 6.5em,
        #0003 6.5em 7.5em,
        #0000 7.5em
      )
      0 100% / 100% 0.5em;
  background-repeat: repeat-x;
  top: 0;
  left: -3em;
  width: 200%;
  height: 100%;
  z-index: 2;
}
@keyframes fill {
  from {
    clip-path: var(--polygonB1);
    -webkit-clip-path: var(--polygonB1);
  }
  10% {
    clip-path: var(--polygonB2);
    -webkit-clip-path: var(--polygonB2);
  }
  45% {
    clip-path: var(--polygonB3);
    -webkit-clip-path: var(--polygonB3);
  }
  80% {
    clip-path: var(--polygonB4);
    -webkit-clip-path: var(--polygonB4);
  }
  85%,
  to {
    clip-path: var(--polygonB5);
    -webkit-clip-path: var(--polygonB5);
  }
}
@keyframes glare {
  from,
  90% {
    transform: translateX(0);
  }
  to {
    transform: translateX(3em);
  }
}
@keyframes flip {
  from,
  90% {
    transform: rotate(0);
  }
  to {
    transform: rotate(180deg);
  }
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17181c;
    --fg: #c7cad1;
  }
}