Limit animation to the .wagtail-logo class so that custom logos don't nod

wagtail/wagtailadmin/static_src/wagtailadmin/scss/core.scss

@@ -385,10 +385,13 @@ footer,
             float: none;
             margin: auto;
             display: block;
+        }
+
+        img.wagtail-logo {
             transition: all 0.25s cubic-bezier(0.28, 0.15, 0, 2.1);
         }
 
-        img:hover {
+        img.wagtail-logo:hover {
             transform: rotate(4deg);
         }
     }

wagtail/wagtailadmin/templates/wagtailadmin/base.html

@@ -6,7 +6,7 @@
         <div class="inner">
             <a href="{% url 'wagtailadmin_home' %}" class="logo" title="Wagtail v.{% wagtail_version %}">
                 {% block branding_logo %}
-                    <img src="{% static 'wagtailadmin/images/wagtail-logo.svg' %}" alt="Wagtail" width="80" />
+                    <img class="wagtail-logo" src="{% static 'wagtailadmin/images/wagtail-logo.svg' %}" alt="Wagtail" width="80" />
                 {% endblock %}
                 <span>{% trans "Dashboard" %}</span>
             </a>