<div class="container">
<div class="row">
<div class="col-6">
<label for="encoded">Encoded</label><textarea id="encoded" class="form-control" name="encoded" rows="16"></textarea>
</div>
<div class="col-6">
<label for="decoded">Decoded</label><textarea id="decoded" class="form-control" name="decoded" rows="16"></textarea>
</div>
<div class="col-12">
<button id="submit" class="btn btn-primary btn-block mt-3">Go</button>
</div>
</div>
</div>