<!-- Thank you Sandeep Virk -->

<!-- Design inspired by: https://dribbble.com/shots/1992789 -->
<form>
  <input type="text" />
  <div class="after"></div>
  <input type="submit" />
</form>
<!-- &nbsp; = Non breaking space
Will not break into a new line -->
<h4>&nbsp;</h4>
<p>Click search, Enter to submit</p>
html {
  background-color: #E62878;
  font-family: "Lucida Grande","Lucida Sans Unicode", Tahoma, Sans-Serif;
}
p {
  text-align: center;
  color: #fff;
  font-size: 14px;
}
h4 {
  color: #fff;
  text-align: center;
  letter-spacing: 0.5px;
/*defines a 2D scale transformation
  scale(x,y) */
  transform: scale(0);
  transition: all 0.3s;
  position: relative;
  top: -25px;
  margin: 0;
  font-weight: normal;
}
h4.show {
  animation: alert 0.18s ease-in-out;
  animation-fill-mode: forwards;
}
@keyframes alert {
  0%{
    transform: scale(0);
  }
  80% {
    transform: scale(1.2);
  }
  100% {
    transform: scale(1);
  }
}
form {
  transition: all 0.15s;
}
form.explode {
  transform: scale(1.4);
  opacity: 0;
}
html {
  padding-top: 100px;
}
form {
  width: 36px;
  height: 36px;
  margin: 0 auto;
  display: block;
  box-sizing: border-box;
  position: relative;
}
input[type="submit"]{
  display: none !important;
}
input {
  width: 100%;
}
input {
  background: none;
  border: 3px solid #fff;
  border-radius: 26px;
  box-sizing: border-box;
  padding: 5px 15px 7px;
  font-size: 14px;
  color: #fff;
  z-index: 2;
  position: relative;
}
input:focus {
  outline: none;
}
.after {
  width: 36px;
  height: 36px;
  position: absolute;
  top: 1px;
  right: 0;
  z-index: 1;
}
form.open .after {
 cursor: pointer;
}
.after:before,
.after:after {
  content: '';
  width: 13px;
  height: 3px;
  background-color: #fff;
  border-radius: 3px;
  position: absolute;
  transform-origin: 100% 100%;
}
.after:after{
  bottom: -3px;
  right: -3px;
  transform: rotate(45deg);
}
.after:before {
  top: -3px;
  right: -3px;
  transform: rotate(-45deg);
  opacity: 0;
}
form,
form .after,
form .after:before,
form .after:after {
  animation-duration: 1.1s;
  animation-fill-mode: forwards;
}
form.in {
  animation-name: expand;
}
form.in .after:before {
  animation-name: beforemagic;
}
form.in .after:after {
  animation-name: aftermagic;
}

form.close,
form.close .after,
form.close .after:before,
form.close .after:after {
  animation-direction: reverse;
}
form.close {
  animation-name: expand;
}
form.close .after:before {
  animation-name: beforemagic;
}
form.close .after:after {
  animation-name: aftermagic;
}

/* Hold final focused state
 ****************************/
form.open {
  width: 250px;
  color: #fff;
}
form.open .after {
  z-index: 3;
}
form.open .after:before {
  width: 20px;
  top: 9px;
  right: 13px;
  opacity: 1;
}
form.open .after:after {
  width: 20px;
  bottom: 10px;
  right: 15px;
}

@keyframes aftermagic {
  0%   {}
  10% {
    width: 24px;
    bottom: -10px;
    right: -10px;
  }
  15%{
    opacity: 1;
  }
  35% {
    width: 13px;
    bottom: -3px;
    right: -3px;
     opacity: 0;
    
  }
  25% {
    opacity: 0;
  }
  64% {
    opacity: 0;
  }
  65% {
    opacity: 1;
    width: 13px;
    bottom: -2px;
    right: -3px;
  }
  75% {
    width: 30px;
    bottom: 4px;
    right: 10px;
  }
  90% {
    width: 20px;
    bottom: 10px;
    right: 15px;
  }
  100% {
    width: 20px;
    bottom: 10px;
    right: 15px;
  }
}
@keyframes beforemagic {
  0%   {}
  50% {
    opacity: 0;
  }
  55% {
    opacity: 1;
    width: 13px;
    top: -4px;
    right: -3px;
  }
  65% {
    width: 30px;
    top: 6px;
    right: 10px;
  }
  80% {
    width: 20px;
    top: 9px;
    right: 13px;
  }
  100% {
    width: 20px;
    top: 9px;
    right: 13px;
    opacity: 1;
  }
}
@keyframes expand {
    0%   {
      color: transparent;
    }
  20% {
    width: 36px;
  }
  45% {
    width: 250px;
  }
  99% {
    color: transparent;
  }
    100% {
      width: 250px;
      color: #fff;
    }
}
var s = $('input'),
    f  = $('form'),
    a = $('.after'),
		m = $('h4');

s.focus(function(){
  if( f.hasClass('open') ) return;
  f.addClass('in');
  setTimeout(function(){
    f.addClass('open');
    f.removeClass('in');
  }, 1300);
});

a.on('click', function(e){
  e.preventDefault();
  if( !f.hasClass('open') ) return;
   s.val('');
  f.addClass('close');
  f.removeClass('open');
  setTimeout(function(){
    f.removeClass('close');
  }, 1300);
})

f.submit(function(e){
  e.preventDefault();
  m.html('Thanks, high five!').addClass('show');
  f.addClass('explode');
  setTimeout(function(){
    s.val('');
    f.removeClass('explode');
    m.removeClass('show');
  }, 3000);
})

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js