JSFiddle - React, Tailwind, and code Playground

HTML

<div class='form-group'>
  <label class='control-label' for='numParcelas'>PARCELAS*</label>
  <input type='text' class='form_campos form_campos_numeros' id='numParcelas' name='numParcelas'>
</div>

<br><br><br><br><br><br>

<div class='box'>
  <label class='control-label' for='auto'>FORNECEDOR*</label>
  <input type='text' class='form_campos_box' id='auto' name='nome'>
  <div class="box_bt">
    <i class='demo-icon'>X</i>
  </div>
</div>

CSS

body {
  font-family: Verdana;
  font-size: 12px;
}

.form-group {
  position: relative;
  display: flex;
  height: 45px;
  float: left;
  margin-right: 2px;
}

.control-label {
  opacity: 0.4;
  pointer-events: none;
  position: absolute;
  transform: translate3d(5px, 22px, 0) scale(1);
  transform-origin: left top;
  transition: 240ms;
  z-index: 2;
}

.form-group.focused .control-label {
  opacity: 1;
  transform: scale(0.75);
}

.form_campos {
  height: 20px;
  color: #484848;
  z-index: 1;
  align-self: flex-end;
  font-size: 15px;
  padding: 5px;
  outline: none;
  border-color: #484848;
  border-style: solid;
  border-bottom-width: 1px;
  border-top-width: 0;
  border-right-width: 0;
  border-left-width: 0;
  background: transparent;
}

.form_campos:hover,
.form_campos:focus {
  border-color: #1E90FF;
}

.form_campos_numeros {
  width: 123px;
}



/* BOX INPUT E BOTAO */

.box {
  width: 250px;
  display: flex;
  height: 44px;
  border-color: #484848;
  border-style: solid;
  border-bottom-width: 1px;
  border-top-width: 0;
  border-right-width: 0;
  border-left-width: 0;
}

.box input {
  outline: 0;
  width: 230px;
  height: 20px;
  border: 0;
  background: transparent;
}

.box_bt {
  margin-top: 28px;
  cursor: pointer;
}

.box.md-focus i ,
.box.md-focus label {
  color: #1E90FF;
  opacity: 1;
}

.box.md-focus {
  border-color: #1E90FF;
}

.box.focused .control-label {
  opacity: 1;
  transform: scale(0.75);
}

.form_campos_box {
  color: #484848;
  z-index: 1;
  align-self: flex-end;
  font-size: 15px;
  padding: 5px;
  position: relative;
  display: block;
  outline: none;
}
/* FIM BOX INPUT E BOTAO */

JavaScript

$('.form_campos').on('focus blur', function(e) {
  $(this).parents('.form-group').toggleClass('focused', (e.type === 'focus' || this.value.length > 0));
}).trigger('blur');

var elem = {};
elem.auto = $("#auto");
elem.box = $(".box");

elem.auto.on("input", function (event) {
  elem.box.toggleClass("md-has-value", elem.auto.val());
});

elem.auto.on("focusin", function (event) {
  elem.box.addClass("md-focus");
});

elem.auto.on("focusout", function (event) {
  elem.box.removeClass("md-focus");
});