JSFiddle - React, Tailwind, and code Playground

HTML

<form id="contact" method="post">
   <div>
       <input id="submit" type="submit" value="Отправить">
    </div>
    <div>
      <input id="submit" type="submit" value="Добавить файл">
    </div>
</form>

CSS

body {
    font-family: 'Ubuntu', sans-serif;
    font-weight:500;
    font-size:18px;
    color:#fff;
    background:#000;}
    
form input[type="submit"]{
    display:block;
    float:left;
    width:13.75em;
    padding:0.55em;
    margin-right:1.1em;
    font-size:1em;
    color:#fff;
    border:none;
    background:#343434;
 }
    
 form input[type="submit"]:hover {
    color:#000;
    background:#fff;
    /* background:#fff url('https://cdn4.iconfinder.com/data/icons/Free-Medical-Icons-Set/32x32/Select.png') no-repeat 16px 4px;} */
    }
    
form input[type="submit"] {
    position:relative;
    margin-right:10px;
    }
    
form div:after {
    content:'';
    position:absolute;
    top:4px;
    left:16px;
    width:32px;
    height:32px;
    /* background: #000; */
background:#fff url('https://cdn4.iconfinder.com/data/icons/Free-Medical-Icons-Set/32x32/Select.png') no-repeat 16px 4px;
    }