kb: style warning notice on old revisions

welco/kb/templates/kb/page_version.html

@@ -9,6 +9,7 @@
 
 {% block content %}
 
+<div class="old-version warning-notice">
 <p>
 {% trans 'Warning: this is an old version of this page.' %}
 </p>
@@ -17,6 +18,7 @@
   {% csrf_token %}
   <button>{% trans 'Revert to this version' %}</button>
 </form>
+</div>
 
 {{block.super}}
 

welco/static/css/style.css

@@ -534,3 +534,31 @@ div.counter a.button {
 div.useful-links {
 	margin-top: 2em;
 }
+
+div.warning-notice {
+	background: #F9DEDE;
+	margin: 1em 0;
+	padding: 1em;
+	padding-left: 4em;
+	position: relative;
+	position: relative;
+}
+
+div.warning-notice p {
+	margin: 0.5ex 0;
+}
+
+div.warning-notice::before {
+	content: "\f06a";
+	font-family: FontAwesome;
+	font-size: 2em;
+	position: absolute;
+	left: 1ex;
+	top: 0.5ex;
+}
+
+div.old-version.warning-notice form {
+	position: absolute;
+	right: 1ex;
+	top: 1ex;
+}