Sample form field with animated bottom border

form.html

    <div class="group">      
      <input type="text" required>
      <span class="highlight"></span>
      <span class="bar"></span>
      <label>Email</label>
    </div>

gistfile1.txt

/* form starting stylings ------------------------------- */
.group 			  { 
  position:relative; 
  margin-bottom:45px; 
}
input 				{
  font-size:18px;
  padding:10px 10px 10px 5px;
  display:block;
  width:300px;
  border:none;
  border-bottom:1px solid #757575;
}
input:focus 		{ outline:none; }

/* LABEL ======================================= */
label 				 {
  color:#999; 
  font-size:18px;
  font-weight:normal;
  position:absolute;
  pointer-events:none;
  left:5px;
  top:10px;
  transition:3.2s ease all; 
  -moz-transition:3.2s ease all; 
  -webkit-transition:3.2s ease all;
}

/* active state */
input:focus ~ label, input:valid ~ label 		{
  top:-20px;
  font-size:14px;
  color:#5264AE;
}

/* BOTTOM BARS ================================= */
.bar 	{ position:relative; display:block; width:300px; }
.bar:before, .bar:after 	{
  content:'';
  height:2px; 
  width:0;
  bottom:1px; 
  position:absolute;
  background:#5264AE; 
  transition:3.2s ease all; 
  -moz-transition:3.2s ease all; 
  -webkit-transition:3.2s ease all;
}
.bar:before {
  left:50%;
}
.bar:after {
  right:50%; 
}

/* active state */
input:focus ~ .bar:before, input:focus ~ .bar:after {
  width:50%;
}

/* HIGHLIGHTER ================================== */
.highlight {
  position:absolute;
  height:60%; 
  width:100px; 
  top:25%; 
  left:0;
  pointer-events:none;
  opacity:0.5;
}

/* active state */
input:focus ~ .highlight {
  -webkit-animation:inputHighlighter 0.3s ease;
  -moz-animation:inputHighlighter 0.3s ease;
  animation:inputHighlighter 0.3s ease;
}