* {
  border: 0;
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --hue: 223;
  --bg: hsl(var(--hue),90%,70%);
  --fg: hsl(var(--hue),90%,10%);
  --primary: hsl(var(--hue),90%,50%);
  --trans-dur: 0.3s;
  font-size: clamp(1rem,0.95rem + 0.25vw,1.25rem);
}

body {
  background-color: var(--bg);
  color: var(--fg);
  display: flex;
  font: 1em/1.5 sans-serif;
  height: 100vh;
  transition: background-color var(--trans-dur), color var(--trans-dur);
}

.hourglass {
  --dur: 2s;
  display: block;
  margin: auto;
  width: 14em;
  height: auto;
}
.hourglass__glare-top, .hourglass__glare-bottom, .hourglass__model, .hourglass__motion-thick, .hourglass__motion-medium, .hourglass__motion-thin, .hourglass__sand-drop, .hourglass__sand-fill, .hourglass__sand-grain-left, .hourglass__sand-grain-right, .hourglass__sand-line-left, .hourglass__sand-line-right, .hourglass__sand-mound-top, .hourglass__sand-mound-bottom {
  animation-duration: var(--dur);
  animation-timing-function: cubic-bezier(0.83, 0, 0.17, 1);
  animation-iteration-count: infinite;
}
.hourglass__glare-top {
  animation-name: glare-top;
}
.hourglass__glare-bottom {
  animation-name: glare-bottom;
}
.hourglass__model {
  animation-name: hourglass-flip;
  transform-origin: 12.25px 16.75px;
}
.hourglass__motion-thick, .hourglass__motion-medium, .hourglass__motion-thin {
  transform-origin: 26px 26px;
}
.hourglass__motion-thick {
  animation-name: motion-thick;
}
.hourglass__motion-medium {
  animation-name: motion-medium;
}
.hourglass__motion-thin {
  animation-name: motion-thin;
}
.hourglass__sand-drop {
  animation-name: sand-drop;
}
.hourglass__sand-fill {
  animation-name: sand-fill;
}
.hourglass__sand-grain-left {
  animation-name: sand-grain-left;
}
.hourglass__sand-grain-right {
  animation-name: sand-grain-right;
}
.hourglass__sand-line-left {
  animation-name: sand-line-left;
}
.hourglass__sand-line-right {
  animation-name: sand-line-right;
}
.hourglass__sand-mound-top {
  animation-name: sand-mound-top;
}
.hourglass__sand-mound-bottom {
  animation-name: sand-mound-bottom;
  transform-origin: 12.25px 31.5px;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: hsl(var(--hue),90%,10%);
    --fg: hsl(var(--hue),90%,90%);
  }
}
/* Animation */
@keyframes hourglass-flip {
  from {
    transform: translate(13.75px, 9.25px) rotate(-180deg);
  }
  24%, to {
    transform: translate(13.75px, 9.25px) rotate(0);
  }
}
@keyframes glare-top {
  from {
    stroke: rgba(255, 255, 255, 0);
  }
  24%, to {
    stroke: white;
  }
}
@keyframes glare-bottom {
  from {
    stroke: white;
  }
  24%, to {
    stroke: rgba(255, 255, 255, 0);
  }
}
@keyframes motion-thick {
  from {
    animation-timing-function: cubic-bezier(0.33, 0, 0.67, 0);
    stroke: rgba(255, 255, 255, 0);
    stroke-dashoffset: 153.94;
    transform: rotate(0.67turn);
  }
  20% {
    animation-timing-function: cubic-bezier(0.33, 1, 0.67, 1);
    stroke: white;
    stroke-dashoffset: 141.11;
    transform: rotate(1turn);
  }
  40%, to {
    stroke: rgba(255, 255, 255, 0);
    stroke-dashoffset: 153.94;
    transform: rotate(1.33turn);
  }
}
@keyframes motion-medium {
  from, 8% {
    animation-timing-function: cubic-bezier(0.33, 0, 0.67, 0);
    stroke: rgba(255, 255, 255, 0);
    stroke-dashoffset: 153.94;
    transform: rotate(0.5turn);
  }
  20% {
    animation-timing-function: cubic-bezier(0.33, 1, 0.67, 1);
    stroke: white;
    stroke-dashoffset: 147.53;
    transform: rotate(0.83turn);
  }
  32%, to {
    stroke: rgba(255, 255, 255, 0);
    stroke-dashoffset: 153.94;
    transform: rotate(1.17turn);
  }
}
@keyframes motion-thin {
  from, 4% {
    animation-timing-function: cubic-bezier(0.33, 0, 0.67, 0);
    stroke: rgba(255, 255, 255, 0);
    stroke-dashoffset: 153.94;
    transform: rotate(0.33turn);
  }
  24% {
    animation-timing-function: cubic-bezier(0.33, 1, 0.67, 1);
    stroke: white;
    stroke-dashoffset: 134.7;
    transform: rotate(0.67turn);
  }
  44%, to {
    stroke: rgba(255, 255, 255, 0);
    stroke-dashoffset: 153.94;
    transform: rotate(1turn);
  }
}
@keyframes sand-drop {
  from, 10% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    stroke-dashoffset: 1;
  }
  70%, to {
    stroke-dashoffset: -107;
  }
}
@keyframes sand-fill {
  from, 10% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    stroke-dashoffset: 55;
  }
  70%, to {
    stroke-dashoffset: -54;
  }
}
@keyframes sand-grain-left {
  from, 10% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    stroke-dashoffset: 29;
  }
  70%, to {
    stroke-dashoffset: -22;
  }
}
@keyframes sand-grain-right {
  from, 10% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    stroke-dashoffset: 27;
  }
  70%, to {
    stroke-dashoffset: -24;
  }
}
@keyframes sand-line-left {
  from, 10% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    stroke-dashoffset: 53;
  }
  70%, to {
    stroke-dashoffset: -55;
  }
}
@keyframes sand-line-right {
  from, 10% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    stroke-dashoffset: 14;
  }
  70%, to {
    stroke-dashoffset: -24.5;
  }
}
@keyframes sand-mound-top {
  from, 10% {
    animation-timing-function: linear;
    transform: translate(0, 0);
  }
  15% {
    animation-timing-function: cubic-bezier(0.12, 0, 0.39, 0);
    transform: translate(0, 1.5px);
  }
  51%, to {
    transform: translate(0, 13px);
  }
}
@keyframes sand-mound-bottom {
  from, 31% {
    animation-timing-function: cubic-bezier(0.61, 1, 0.88, 1);
    transform: scale(1, 0);
  }
  56%, to {
    transform: scale(1, 1);
  }
}