JSFiddle - React, Tailwind, and code Playground

HTML

<form method="POST" action="myurl"> 
<div class="b px-4 py-2 mt-4"><span class="bb">+</span> <br /><small> Drag & drop your text files here</small>
    <input type="file" name="file">
    
</form><

CSS

/*Copied from bootstrap */
 .btn {
    display: inline-block;
    padding: 6px 12px;
    margin-bottom: 0;
    font-size: 14px;
    font-weight: normal;
    line-height: 1.42857143;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    background-image: none;
    border: 1px solid transparent;
    border-radius: 4px;
}
/*Also */
 .btn-success {
    color: #fff;
    background-color: #5cb85c;
    border-color: #4cae4c;
}
/* This is copied from https://github.com/blueimp/jQuery-File-Upload/blob/master/css/jquery.fileupload.css */
 .fileinput-button {
    position: relative;
    overflow: hidden;
}
/*Also*/
 .fileinput-button input {
    position: absolute;
    top: 0;
    right: 0;
    margin: 0;
    opacity: 0;
    -ms-filter:'alpha(opacity=0)';
    font-size: 200px;
    direction: ltr;
    cursor: pointer;
}