$timing-function-deceleration: cubic-bezier(0, 0, .2, 1) !default;
$timing-function-standard: cubic-bezier(.4, 0, .2, 1) !default;
$timing-function-acceleration: cubic-bezier(.4, 0, 1, 1) !default;
$timing-function-sharp: cubic-bezier(.4, 0, .6, 1) !default;

@keyframes pulse {
  0% {opacity: 1;}
  50% {opacity: .7;}
  100% {opacity: 1;}
}

@mixin pulse-animation {
  animation: pulse 1s infinite;
  animation-timing-function: ease-in-out;
}