JSFiddle - React, Tailwind, and code Playground

HTML

<div id="MessageBox" class="ui-dialog-content ui-widget-content" style="width: auto; min-height: 40.8333px; height: auto;" scrolltop="0" scrollleft="0">
    
<div class="popupKey">Bank Reference</div>
<div class="popupValue">abc</div>
<br>
<div class="popupKey">Amount</div>
<div class="popupValue">650.00</div>
<br>
<div class="popupKey">Currency</div>
<div class="popupValue">GBP</div>
<br>
<div class="popupKey">PaymentDate</div>
<div class="popupValue">02/06/2011</div>
<br>
<div class="popupKey">Remitter</div>
<div class="popupValue"></div>
<br>
<div class="popupKey">Senders Reference</div>
<div class="popupValue"></div>
<br>
</div>

CSS

.popupKey 
{
    display : inline-block;
    min-width: 150px;
}

.popupValue 
{
    display : inline-block;
    min-width: 150px;
}