<div class="search-form">
  <form>
    <input type="text">
    <button></button>
  </form>
</div>

* {
  outline: none;
  border: none;
  padding: 0;
}

body {
  background-color: rgb(71, 136, 135);
}

.search-form {
  position: relative;
  margin: 150px auto 0;
  width: 300px;
}

.search-form:before {
  content: ' ';
  position: absolute;
  left: 25px;
  top: 14px;
  width: 2px;
  height: 36px;
  transform: scale(0);
  z-index: 1;
  background: rgb(71, 136, 135);
  transition: all 0.5s cubic-bezier(.87, -.41, .19, 1.44);
}

.active:before {
  transform: scale(1);
  transition-delay: 0.3s;
  animation: 0.6s cubic-bezier(.87, -.41, .19, 1.44) 0.5s infinite forwards focus;
}

input {
  border-radius: 36px;
  position: absolute;
  width: 64px;
  height: 64px;
  transition: all 0.5s cubic-bezier(.87, -.41, .19, 1.44);
}

.active input {
  width: 100%;
  padding-left: 25px;
  border-radius: 36px;
}

button {
  background: rgba(255, 255, 255, 1);
  position: absolute;
  height: 100%;
  border-radius: 50%;
  width: 64px;
  height: 64px;
  transition: all 0.5s cubic-bezier(.87, -.41, .19, 1.44);
}

button:after {
  content: ' ';
  position: absolute;
  width: 32px;
  height: 32px;
  left: 0;
  right: 0;
  transform: translateY(-50%);
  margin: 0 auto;
  background: rgb(254, 111, 117);
  border-radius: 50%;
}

button:before {
  content: ' ';
  position: absolute;
  width: 24px;
  height: 24px;
  left: 0;
  right: 0;
  top: 20px;
  transform: scale(0);
  transform-origin: left top;
  margin: 0 auto;
  background: white;
  border-radius: 50%;
  z-index: 1;
  transition: all 0.8s ease;
}

.active button {
  transform: translateX(260px);
}

.active button:before {
  transform: scale(1);
}

.focus:before {
  transform: scale(0);
  animation: none;
}

@keyframes focus {
  0 {
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

var input = document.querySelector('.search-form');
var search = document.querySelector('input')
var button = document.querySelector('button');
button.addEventListener('click', function(e) {
  e.preventDefault();
  input.classList.toggle('active');
})
search.addEventListener('focus', function() {
  input.classList.add('focus');
})

search.addEventListener('blur', function() {
  search.value.length != 0 ? input.classList.add('focus') : input.classList.remove('focus');
})