Dirty nbsp-based trick (so sue me)

Only guaranteed to look nice on target machine in landscape

index.html

             <button onclick="playSound('maayan-tsadka-an-audio-guide-to-ocupation-part-1-d.mp3')" class="btn btn-secondary text-center w-100 h-100" style="padding-top:0; vertical-align:top">
               <h3>
                 <strong>D.</strong> Means of Resistance
-              <h5>&nbsp;</h5>
+              <h5>&nbsp;<br/>&nbsp;</h5>
               </h3>
             </button>
           </div>