JSFiddle - React, Tailwind, and code Playground

HTML

<form action="#">
  <textarea rows="1" cols="1" placeholder="Текст сообщения"></textarea>
  <button type="submit" class="submit">Отправить</button>
</form>

CSS

textarea{
	position: relative;
	display: block;
	width: 30%;
	padding: 10px 5px;
	background: #f5f6f8;
	border: none;
	border-bottom: 2px solid #4f5b60;  
}
textarea:focus, input:focus{
    outline: none;
}
*:focus {
    outline: none;
}
::-webkit-input-placeholder {
   font-size: 14px;
   color: #c4ced3;
}
:-moz-placeholder { /* Firefox 18- */
   font-size: 14px;
   color: #c4ced3;  
}
::-moz-placeholder {  /* Firefox 19+ */
   font-size: 14px;
   color: #c4ced3;  
}
:-ms-input-placeholder {  
   font-size: 14px;
   color: #c4ced3;  
}
button.submit{
	display: block;
	float: right;
	clear: both;
	border: none;
}