@keyframes fadeIn { 0% { opacity: 0; } }

.hrwaterfall hr {
  animation: fadeIn 0s forwards 0s linear;
}

.hrwaterfall hr:first-child { margin: 1rem 0 0; }
.hrwaterfall hr+hr { margin: 1px; animation-duration: 0.25s; opacity: 0.95; }
.hrwaterfall hr+hr+hr { margin: 2px; animation-duration: 0.5s; opacity: 0.90; }
.hrwaterfall hr+hr+hr+hr { margin: 3px; animation-duration: 0.75s; opacity: 0.85; }
.hrwaterfall hr+hr+hr+hr+hr { margin: 4px; animation-duration: 1s; opacity: 0.80; }
.hrwaterfall hr+hr+hr+hr+hr+hr { margin: 6px; animation-duration: 1.25s; opacity: 0.75; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr { margin: 8px; animation-duration: 1.5s; opacity: 0.70; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr { margin: 10px; animation-duration: 2s; opacity: 0.65; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 12px; animation-duration: 2.5s; opacity: 0.60; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 14px; animation-duration: 3s; opacity: 0.55; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 16px; animation-duration: 3.75s; opacity: 0.50; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 18px; animation-duration: 4.5s; opacity: 0.45; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 20px; animation-duration: 5.25s; opacity: 0.40; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 23px; animation-duration: 6s; opacity: 0.35; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 26px; animation-duration: 7s; opacity: 0.30; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 29px; animation-duration: 8s; opacity: 0.25; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 32px; animation-duration: 9s; opacity: 0.20; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 36px; animation-duration: 10s; opacity: 0.15; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 40px; animation-duration: 12s; opacity: 0.10; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 44px; animation-duration: 15s; opacity: 0.07; }
.hrwaterfall hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr+hr { margin: 50px; animation-duration: 20s; opacity: 0.05; }