$borderColorFocus: $focusColor;

.inputfieldbar  { position:relative; display:block; width:100%; }
.inputfieldbar:before, .inputfieldbar:after   {
  content:'';
  height:1px; 
  width:0;
  bottom:1px; 
  position:absolute;
  background:$borderColorFocus; 
  transition:0.2s ease all; 
  -moz-transition:0.2s ease all; 
  -webkit-transition:0.2s ease all;
}
.inputfieldbar:before {
  left:50%;
}
.inputfieldbar:after {
  right:50%; 
}

input:focus ~ .inputfieldbar:before, input:focus ~ .inputfieldbar:after {
  width:50%;
}