Button position changes for different browsers

Site URL: https://www.thepush.com.au

Any advice or pointers  would be greatly appreciated.

 I am getting different results between chrome and safari with positioning my submit button.

Safari is on the left of the image 

********************************************* Embed code

<div class="push-sub"><h4>Stay connected</h4><form class="js-cm-form" id="subForm" action="https://www.createsend.com/t/subscribeerror?description=" method="post" data-id="XXXXX"><div><label></label><input placeholder="   Email Address" autocomplete="Email" aria-label="Email" class="js-cm-email-input Nqa-input-email" id="fieldEmail" maxlength="200" name="cm-yhhhlty-yhhhlty" required="" type="email"></div>
<div><div><div class="form-inline">
 <fieldset> 
<div><p class="Bsignupdeets"><input id="3012253" name="cm-fo-jtlyudi" type="checkbox" value="3012253"><label for="3012253">   General   </label>
<input id="3012254" name="cm-fo-jtlyudi" type="checkbox" value="3012254"><label for="3012254">   Young People   </label>
  <input id="3012255" name="cm-fo-jtlyudi" type="checkbox" value="3012255"><label for="3012255">     Friend of The Push    </label></div></fieldset></div>
 <button class="Nsubmitbutton" type="submit">Sign up</button> 
  </div></div>
</form></div><script type="text/javascript" src="https://js.createsend1.com/javascript/copypastesubscribeformlogic.js"></script>
<p class="signupdeets">
<b>By signing up you agree to our <a href="https://www.thepush.com.au/privacypolicy"><u>privacy policy</u></a> and <a href="https://www.thepush.com.au/collectionnotice"><u>collection notice</u><b/></a>