JSFiddle - React, Tailwind, and code Playground

HTML

<form id="login-form" action="/login_check" method="post" name="loginform" class="w50 center ma2 pa1">
                                
<div class="autogrid2">
                        <div class="form-container">
                            <input type="text" name="name_username" id="id1" value="" required="required" autofocus="autofocus">
                            <label for="id1">Nom d'utilisateur&nbsp;*</label>
                        </div>

                        <div class="form-container">
                            <input class="box" type="password" name="_password" id="id2" value="" required="required">
                            <label for="id2">Mot de passe&nbsp;*</label>
                        </div>

                        <div>
                            <input type="checkbox" id="remember_me" name="remember_me">
                            <label for="remember_me">Se souvenir de moi</label>
                        </div>

                        
                    </div>
                    
                    <div class="txtcenter mt2">
                    </div>

                            </form>

CSS

.form-container {
  margin: 5px 0;
  overflow: hidden;
  position: relative;
}
.form-container label {
  -webkit-border-top-right-radius: 0;
  -webkit-border-bottom-right-radius: 5px;
  -webkit-border-bottom-left-radius: 0;
  -webkit-border-top-left-radius: 0;
  -moz-border-radius-topright: 0;
  -moz-border-radius-bottomright: 5px;
  -moz-border-radius-bottomleft: 0;
  -moz-border-radius-topleft: 0;
  border-top-right-radius: 0;
  border-bottom-right-radius: 5px;
  border-bottom-left-radius: 0;
  border-top-left-radius: 0;
  -moz-background-clip: padding-box;
  -webkit-background-clip: padding-box;
  background-clip: padding-box;
  background: #7f7363;
  color: white;
  font-size: 80%;
  font-weight: bold;
  left: 0;
  margin: 0;
  padding: 1px 6px;
  position: absolute;
  text-transform: uppercase;
  top: 2px;
}
.form-container input,
.form-container textarea,
.form-container select {
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
  background: #ffffff;
  border: 2px solid #7f7363;
  margin-top: 0;
  padding: 20px 6px 4px 6px;
  outline: 0;
  width: 100%;
}
.form-container input:focus,
.form-container textarea:focus,
.form-container select:focus {
  background: #ffffff;
  border-color: #ff9c00;
}
.form-container input:focus + label,
.form-container textarea:focus + label,
.form-container select:focus + label {
  background-color: #ff9c00;
}
.form-container textarea {
  display: block;
  resize: vertical;
}