diff --git a/public/css/icinga/widgets.less b/public/css/icinga/widgets.less
index eb7338879..6ac5cefba 100644
--- a/public/css/icinga/widgets.less
+++ b/public/css/icinga/widgets.less
@@ -1,5 +1,46 @@
 /*! Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
 
+table.historycolorgrid {
+  font-size: 1.5em;
+}
+
+table.historycolorgrid th {
+  width: 1em;
+  height: 1em;
+  margin: 0.5em;
+  font-size: 0.55em;
+  font-weight: normal;
+}
+
+table.historycolorgrid td {
+  width: 1em;
+  height: 1em;
+  margin: 1em;
+}
+
+table.historycolorgrid td:hover {
+  opacity: 0.5;
+}
+
+table.historycolorgrid td.weekday {
+  font-size: 0.55em;
+  font-weight: normal;
+  width: 2.5em;
+  opacity: 1.0;
+}
+
+table.historycolorgrid a, table.historycolorgrid span {
+  margin: 0;
+  text-decoration: none;
+  display: block;
+  width: 1em;
+  height: 1em;
+}
+
+table.historycolorgrid a:hover {
+  text-decoration: none;
+}
+
 table.multiselect tr[href] td {
   user-select: none;
   -webkit-user-select: none;