Make styling more like rest of new UI

templates/selectidp-dropdown.twig

@@ -5,10 +5,11 @@
     <h2>{{ pagetitle }}</h2>
 
     <p>{{ "Please select the identity provider where you want to authenticate:" | trans }}</p>
-    <form method="get" action="{{ urlpattern }}">
+    <form method="get" action="{{ urlpattern }}" class="pure-form">
         <input type="hidden" name="entityID" value="{{ entityID }}">
         <input type="hidden" name="return" value="{{ return }}">
         <input type="hidden" name="returnIDParam" value="{{ returnIDParam }}">
+        <div class="pure-control-group">
         <select id="dropdownlist" name="idpentityid" autofocus>
         {% for idpentry in idplist %}
             <option value="{{ idpentry.entityid }}"
@@ -18,10 +19,13 @@
             >{{ idpentry.name }}</option>
         {% endfor %}
         </select>
-        <button class="btn" type="submit">{{ 'Select' | trans }}</button>
-	{% if rememberenabled %}
-            <br/><input type="checkbox" name="remember" id="remember" value="1">
+        <button class="btn pure-button" type="submit">{{ 'Select' | trans }}</button>
+        </div>
+        {% if rememberenabled %}
+        <div class="pure-control-group">
+            <input type="checkbox" name="remember" id="remember" value="1">
             <label for="remember">{{ 'Remember my choice' | trans }}</label>
+        </div>
         {% endif %}
     </form>
 {% endblock %}