@keyframes pulse-input {
  0% { background-color: hsl(60, 40%, 50%); }
  25% { background-color: hsl(60, 45%, 50%); }
  50% { background-color: hsl(60, 50%, 50%); }
  75% { background-color: hsl(0, 0%, 70%); }
  100% { background-color: hsl(0, 0%, 70%); }
}

@-moz-keyframes pulse-input {
  0% { background-color: hsl(60, 40%, 50%); }
  25% { background-color: hsl(60, 45%, 50%); }
  50% { background-color: hsl(60, 50%, 50%); }
  75% { background-color: hsl(0, 0%, 70%); }
  100% { background-color: hsl(0, 0%, 70%); }
}

@-webkit-keyframes "pulse-input" {
  0% { background-color: hsl(60, 40%, 50%); }
  25% { background-color: hsl(60, 45%, 50%); }
  50% { background-color: hsl(60, 50%, 50%); }
  75% { background-color: hsl(0, 0%, 70%); }
  100% { background-color: hsl(0, 0%, 70%); }
}

.block__input {
  background-color: hsl(0, 0%, 70%);
  width: 100%;

  &:focus {
    -webkit-animation: pulse-input 1.5s linear;
       -moz-animation: pulse-input 1.5s linear;
            animation: pulse-input 1.5s linear;

    -webkit-animation-iteration-count: infinite;
       -moz-animation-iteration-count: infinite;
            animation-iteration-count: infinite;
  }
}
