JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<div class="panel panel-default">
  <div class="panel-body">

    <form class="form-inline">
      <div class="form-group">
        <label for="inputPassword4">Password</label>
        <input type="password" id="inputPassword4" class="form-control mx-sm-3" aria-describedby="passwordHelpInline">
        <small id="passwordHelpInline" class="text-muted">
      Must be 8-20 characters long.
    </small>
      </div>
    </form>

    <form class="form-horizontal">
      <div class="row">
        <div class="col-xs-12">
          <div class="form-group">
            <label for="email" class="col-sm-4 control-label">in</label>
            <div class="col-xs-4 pull-right">
              <input type="text" class="form-control" placeholder="Postcode" />
            </div>
            <div class="col-xs-4  pull-right">
              <input type="text" class="form-control" placeholder="Postcode" />
            </div>
          </div>
        </div>
      </div>
      <label for="" class="col-xs-12">Pre-LASIK Keratometry values:</label>

      <div class="row">
        <div class="col-xs-6">
          <input type="text" class="form-control col-6" placeholder=".col-3">
        </div>
        <div class="col-xs-6">
          <input type="text" class="form-control" placeholder=".col-4">
        </div>
        <div class="col-xs-6">
          <input type="text" class="form-control col-6" placeholder=".col-3">
        </div>
        <div class="col-xs-6">
          <input type="text" class="form-control" placeholder=".col-4">
        </div>
      </div>
      <div class="row">
        <div class="col-xs-6">
          <div class="form-group">
            <label for="email" class="col-xs-2 control-label">under</label>
            <div class="col-xs-10">
              <select class="form-control">
       ...

CSS

.panel-default {
  background-color: #e6ed9f;
}

.arh .cover-col {
  height: 6em;
}

.cover-col .btn {
  display: block;
  width: 100%;
  height: 100%;
  padding-left: 15px;
  padding-right: 15px;
}

.cover-col .form-group {
  height: 100%;
  margin-bottom: 0;
}

.cover-col .form-group > div {
  height: 100%;
}