html {
  height: 100%;
}

body {
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: linear-gradient(to bottom, #202020, #111119);
}

.rain {
  position: absolute;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
}

.rain.back-row {
  display: none;
  z-index: 1;
  bottom: 60px;
  opacity: 0.5;
}

body.back-row-toggle .rain.back-row {
  display: block;
}

.drop {
  position: absolute;
  bottom: 100%;
  width: 15px;
  height: 120px;
  pointer-events: none;
  animation: drop 0.5s linear infinite;
}

@keyframes drop {
  0% {
    transform: translateY(0vh);
  }
  75% {
    transform: translateY(90vh);
  }
  100% {
    transform: translateY(90vh);
  }
}

.stem {
  width: 1px;
  height: 60%;
  margin-left: 7px;
  background: linear-gradient(to bottom, rgba(255, 255, 255, 0), rgba(255, 255, 255, 0.25));
  animation: stem 0.5s linear infinite;
}

@keyframes stem {
  0% {
    opacity: 1;
  }
  65% {
    opacity: 1;
  }
  75% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}

.splat {
  width: 15px;
  height: 10px;
  border-top: 2px dotted rgba(255, 255, 255, 0.5);
  border-radius: 50%;
  opacity: 1;
  transform: scale(0);
  animation: splat 0.5s linear infinite;
  display: none;
}

body.splat-toggle .splat {
  display: block;
}

@keyframes splat {
  0% {
    opacity: 1;
    transform: scale(0);
  }
  80% {
    opacity: 1;
    transform: scale(0);
  }
  90% {
    opacity: 0.5;
    transform: scale(1);
  }
  100% {
    opacity: 0;
    transform: scale(1.5);
  }
}

.toggles {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 3;
}

.toggle {
  position: absolute;
  left: 20px;
  width: 50px;
  height: 50px;
  line-height: 51px;
  box-sizing: border-box;
  text-align: center;
  font-family: sans-serif;
  font-size: 10px;
  font-weight: bold;
  background-color: rgba(255, 255, 255, 0.2);
  color: rgba(0, 0, 0, 0.5);
  border-radius: 50%;
  cursor: pointer;
  transition: background-color 0.3s;
}

.toggle:hover {
  background-color: rgba(255, 255, 255, 0.25);
}

.toggle:active {
  background-color: rgba(255, 255, 255, 0.3);
}

.toggle.active {
  background-color: rgba(255, 255, 255, 0.4);
}

.splat-toggle {
  top: 20px;
}

.back-row-toggle {
  top: 90px;
  line-height: 12px;
  padding-top: 14px;
}

.single-toggle {
  top: 160px;
}

body.single-toggle .drop {
  display: none;
}

body.single-toggle .drop:nth-child(10) {
  display: block;
}

var makeItRain = function() {
  //clear out everything
  $('.rain').empty();

  var increment = 0;
  var drops = "";
  var backDrops = "";

  while (increment < 100) {
    //couple random numbers to use for various randomizations
    //random number between 98 and 1
    var randoHundo = (Math.floor(Math.random() * (98 - 1 + 1) + 1));
    //random number between 5 and 2
    var randoFiver = (Math.floor(Math.random() * (5 - 2 + 1) + 2));
    //increment
    increment += randoFiver;
    //add in a new raindrop with various randomizations to certain CSS properties
    drops += '<div class="drop" style="left: ' + increment + '%; bottom: ' + (randoFiver + randoFiver - 1 + 100) + '%; animation-delay: 0.' + randoHundo + 's; animation-duration: 0.5' + randoHundo + 's;"><div class="stem" style="animation-delay: 0.' + randoHundo + 's; animation-duration: 0.5' + randoHundo + 's;"></div><div class="splat" style="animation-delay: 0.' + randoHundo + 's; animation-duration: 0.5' + randoHundo + 's;"></div></div>';
    backDrops += '<div class="drop" style="right: ' + increment + '%; bottom: ' + (randoFiver + randoFiver - 1 + 100) + '%; animation-delay: 0.' + randoHundo + 's; animation-duration: 0.5' + randoHundo + 's;"><div class="stem" style="animation-delay: 0.' + randoHundo + 's; animation-duration: 0.5' + randoHundo + 's;"></div><div class="splat" style="animation-delay: 0.' + randoHundo + 's; animation-duration: 0.5' + randoHundo + 's;"></div></div>';
  }

  $('.rain.front-row').append(drops);
  $('.rain.back-row').append(backDrops);
}

$('.splat-toggle.toggle').on('click', function() {
  $('body').toggleClass('splat-toggle');
  $('.splat-toggle.toggle').toggleClass('active');
  makeItRain();
});

$('.back-row-toggle.toggle').on('click', function() {
  $('body').toggleClass('back-row-toggle');
  $('.back-row-toggle.toggle').toggleClass('active');
  makeItRain();
});

$('.single-toggle.toggle').on('click', function() {
  $('body').toggleClass('single-toggle');
  $('.single-toggle.toggle').toggleClass('active');
  makeItRain();
});

makeItRain();