JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://openlayers.org/en/v3.19.1/build/ol-debug.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/milligram/1.2.4/milligram.css">
<link rel="stylesheet" href="http://openlayers.org/en/v3.19.1/css/ol.css">
<div class="container">

  <!-- first row -->
	<div class="row">
    <div class="column column-100">
      <div id="map" style="height: 600px; z-index: 1"></div>
    </div>
	</div>
  
  <!-- second row -->
  <div class="row">
    <div class="column">
      <div><input type="text"></div>
    </div>
    <div class="column">
      <div><input type="text"></div>
    </div>
  </div>
  
</div>

CSS

body, html {
  height: 100%;
}

.container {
  height: 100%;
}

JavaScript

var map = new ol.Map({
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  target: 'map',
  view: new ol.View({
    center: [0, 0],
    zoom: 2
  })
});