fix(perunaup): fix btn size and color

templates/perun-aup-tpl.php

 <?php declare(strict_types=1);
 
+use SimpleSAML\Module;
 use SimpleSAML\Module\perun\Auth\Process\PerunAup;
 
 $this->data['header'] = $this->t('{perun:perun:aup_header}');
-
+$this->data['head'] = '<link rel="stylesheet"  media="screen" type="text/css" href="' .
+    Module::getModuleUrl('perun/res/css/perun_aup.css') . '" />';
 $this->includeAtTemplateBase('includes/header.php');
 
 ?>
@@ -11,7 +13,7 @@ $this->includeAtTemplateBase('includes/header.php');
 <div class="row">
     <div>
         <p><?php echo $this->t('{perun:perun:aup_text}'); ?></p>
-        <a class="btn btn-block btn-primary" href="<?php echo $this->data[PerunAup::PARAM_APPROVAL_URL]; ?>">
+        <a class="btn btn-lg btn-block btn-primary" href="<?php echo $this->data[PerunAup::PARAM_APPROVAL_URL]; ?>">
             <?php echo $this->t('{perun:perun:aup_button}'); ?>
         </a>
     </div>