JSFiddle - React, Tailwind, and code Playground

HTML

<div class="navbar">
  <a href="#">Тест</a>
</div>
<div class="slider">
  Text
</div>

CSS

.navbar {
  background-color: rgba(0, 0, 0, 0.9);
  position: fixed;
  width: 100%;
  text-align: center;
  top: 0;
  font-size: 30px;
  opacity: 0.99;
}

.navbar a {
  color: #FF0000;
  text-decoration: none;
}

.slider {
  background-color: rgba(0, 0, 255, 0.9);
  margin-top: 50px;
  text-align: center;
  color: #fff;
  width: 100%;
  font-size: 20px;
}

.animated {
  -webkit-animation: cd-pulse 3s infinite;
  -moz-animation: cd-pulse 3s infinite;
  animation: cd-pulse 3s infinite;
}

@-webkit-keyframes cd-pulse {
  0% {
    -webkit-transform: translateY(-50%) scale(1);
    opacity: 1;
  }
  40% {
    -webkit-transform: translateY(-50%) scale(0.9);
    opacity: 0;
  }
  100% {
    -webkit-transform: translateY(-50%) scale(0);
    opacity: 0;
  }
}

@-moz-keyframes cd-pulse {
  0% {
    -moz-transform: translateY(-50%) scale(1);
    opacity: 1;
  }
  40% {
    -moz-transform: translateY(-50%) scale(0.9);
    opacity: 0;
  }
  100% {
    -moz-transform: translateY(-50%) scale(0);
    opacity: 0;
  }
}

@keyframes cd-pulse {
  0% {
    -webkit-transform: translateY(-50%) scale(1);
    -moz-transform: translateY(-50%) scale(1);
    -ms-transform: translateY(-50%) scale(1);
    -o-transform: translateY(-50%) scale(1);
    transform: translateY(-50%) scale(1);
    opacity: 1;
  }
  40% {
    -webkit-transform: translateY(-50%) scale(0.9);
    -moz-transform: translateY(-50%) scale(0.9);
    -ms-transform: translateY(-50%) scale(0.9);
    -o-transform: translateY(-50%) scale(0.9);
    transform: translateY(-50%) scale(0.9);
    opacity: 0;
  }
  100% {
    -webkit-transform: translateY(-50%) scale(0);
    -moz-transform: translateY(-50%) scale(0);
    -ms-transform: translateY(-50%) scale(0);
    -o-transform: translateY(-50%) scale(0);
    transform: translateY(-50%) scale(0);
    opacity: 0;
  }
}

JavaScript

setInterval(function() {
  if ($('.slider').hasClass('animated'))
    $('.slider').removeClass('animated');
  else
    $('.slider').addClass('animated');
}, 3000);