zap-desktop/app/animated_checkmark.scss

$curve: cubic-bezier(0.65, 0, 0.45, 1);

.checkmark__circle {
  stroke-dasharray: 166;
  stroke-dashoffset: 166;
  stroke-width: 2;
  stroke-miterlimit: 10;
  stroke: $green;
  fill: none;
  animation: stroke 0.6s $curve forwards;
}

.checkmark {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  stroke-width: 2;
  stroke: #fff;
  stroke-miterlimit: 10;
  box-shadow: inset 0 0 0 $green;
  animation: fill 0.4s ease-in-out 0.4s forwards, scale 0.3s ease-in-out 0.9s both;
}

.checkmark__check {
  transform-origin: 50% 50%;
  stroke-dasharray: 48;
  stroke-dashoffset: 48;
  animation: stroke 0.3s $curve 0.8s forwards;
}

@keyframes stroke {
  100% {
    stroke-dashoffset: 0;
  }
}

@keyframes scale {
  0%,
  100% {
    transform: none;
  }

  50% {
    transform: scale3d(1.1, 1.1, 1);
  }
}

@keyframes fill {
  100% {
    box-shadow: inset 0 0 0 30px $green;
  }
}