diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 52bfe757..67fccb6d 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -2638,7 +2638,7 @@ class calendar extends rcube_plugin
       && ($response['action'] == 'rsvp' || $response['action'] == 'import')
     ) {
       $calendars = $this->driver->list_calendars($mode);
-      $calendar_select = new html_select(array('name' => 'calendar', 'id' => 'itip-saveto', 'is_escaped' => true));
+      $calendar_select = new html_select(array('name' => 'calendar', 'id' => 'itip-saveto', 'is_escaped' => true, 'class' => 'form-control'));
       $calendar_select->add('--', '');
       $numcals = 0;
       foreach ($calendars as $calendar) {
@@ -2912,7 +2912,7 @@ class calendar extends rcube_plugin
             ) . '%before%' . $this->mail_agenda_event_row($event, 'current') . '%after%');
         }
 
-        $html .= html::div('calendar-invitebox',
+        $html .= html::div('calendar-invitebox invitebox boxinformation',
           $this->itip->mail_itip_inline_ui(
             $event,
             $ical_objects->method,
diff --git a/plugins/libkolab/skins/elastic/include/calendar.less b/plugins/libkolab/skins/elastic/include/calendar.less
index 2ea170fd..f4c6f9c5 100644
--- a/plugins/libkolab/skins/elastic/include/calendar.less
+++ b/plugins/libkolab/skins/elastic/include/calendar.less
@@ -50,3 +50,41 @@ fieldset.categories .input-group {
         }
     }
 }
+
+.calendar-invitebox {
+    & > i.icon:before {
+        content: @fa-var-calendar !important;
+    }
+}
+
+.calendar-agenda-preview {
+    display: none;
+    margin-top: .5rem;
+    border-top: 1px solid #ddd;
+
+    h3 {
+        margin-top: .5rem;
+    }
+
+    .event-row {
+        white-space: nowrap;
+        .overflow-ellipsis;
+
+        &.current {
+            color: #333;
+            font-weight: bold;
+        }
+
+        &.no-event {
+            color: @color-black-shade-text;
+            font-style: italic;
+        }
+    }
+
+    .event-title {
+        padding-left: .5rem;
+    }
+
+    .event-date {
+    }
+}
diff --git a/plugins/libkolab/skins/elastic/include/libcalendaring.less b/plugins/libkolab/skins/elastic/include/libcalendaring.less
new file mode 100644
index 00000000..826125b9
--- /dev/null
+++ b/plugins/libkolab/skins/elastic/include/libcalendaring.less
@@ -0,0 +1,146 @@
+/**
+ * Kolab core library
+ *
+ * This file contains Elastic skin styles for libcalendaring plugin.
+ *
+ * @author Aleksander Machniak <machniak@kolabsys.com>
+ *
+ * Copyright (C) 2012-2018, Kolab Systems AG <contact@kolabsys.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+.invitebox {
+    & > i.icon {
+        position: absolute;
+        top: 0;
+        padding-top: .5em;
+    }
+
+    & > span {
+        padding-left: 2.5em;
+    }
+
+    td {
+        padding: 2px;
+
+        &.ititle {
+            font-weight: bold;
+            padding-right: 0.5em;
+        }
+
+        &.label {
+            color: #666;
+            padding-right: 1em;
+        }
+
+        &.sensitivity {
+            font-weight: bold;
+        }
+
+        &.recurrence-id {
+            text-transform: uppercase;
+            font-style: italic;
+        }
+
+        &.date.modified {
+            font-weight: bold;
+            color: @color-error;
+        }
+
+        em {
+            font-weight: bold;
+        }
+    }
+
+    .itip-buttons {
+        display: flex;
+        flex-wrap: wrap;
+
+        input.button {
+            margin: 0 .25rem .25rem 0;
+        }
+    }
+
+    .rsvp-buttons {
+        width: 100%;
+    }
+
+    .itip-reply-controls {
+        margin-top: .25rem;
+
+        a {
+            margin-left: 1em;
+        }
+    }
+
+    .rsvp-status {
+        margin: .5rem 0;
+
+        &.hint {
+            color: #666;
+            font-style: italic;
+        }
+
+        &:before {
+            line-height: 1.1;
+            color: lighten(@color-black, 25%);
+        }
+
+        &.loading:before {
+            &:extend(.font-icon-class);
+            .animated-icon-class;
+            content: @fa-var-circle-notch;
+            line-height: 1;
+        }
+
+        &.declined:before {
+            &:extend(.font-icon-class);
+            content: @fa-var-ban;
+            color: @color-error;
+        }
+
+        &.tentative:before {
+            &:extend(.font-icon-class);
+            content: @fa-var-check-circle;
+            color: @color-warning;
+        }
+
+        &.accepted:before {
+            &:extend(.font-icon-class);
+            content: @fa-var-check-circle;
+            color: @color-success;
+        }
+
+        &.delegated:before {
+            &:extend(.font-icon-class);
+            content: @fa-var-share;
+        }
+
+        &.needs-action:before {
+            &:extend(.font-icon-class);
+            content: @fa-var-question-circle;
+        }
+    }
+
+    .folder-select {
+        white-space: nowrap;
+
+        select {
+            display: initial;
+            width: auto;
+        }
+    }
+}
+
diff --git a/plugins/libkolab/skins/elastic/include/tasklist.less b/plugins/libkolab/skins/elastic/include/tasklist.less
index efcc65ca..fed0749d 100644
--- a/plugins/libkolab/skins/elastic/include/tasklist.less
+++ b/plugins/libkolab/skins/elastic/include/tasklist.less
@@ -27,3 +27,9 @@
         content: @fa-var-tasks;
     }
 }
+
+.tasklist-invitebox {
+    & > i.icon:before {
+        content: @fa-var-tasks !important;
+    }
+}
diff --git a/plugins/libkolab/skins/elastic/libkolab.less b/plugins/libkolab/skins/elastic/libkolab.less
index e5d605d1..a7f4eb62 100644
--- a/plugins/libkolab/skins/elastic/libkolab.less
+++ b/plugins/libkolab/skins/elastic/libkolab.less
@@ -282,4 +282,5 @@ a.history {
 @import "include/kolab_files";
 @import "include/kolab_notes";
 @import "include/kolab_tags";
+@import "include/libcalendaring";
 @import "include/tasklist";
diff --git a/plugins/tasklist/tasklist.php b/plugins/tasklist/tasklist.php
index 47461d6b..62313d4a 100644
--- a/plugins/tasklist/tasklist.php
+++ b/plugins/tasklist/tasklist.php
@@ -1884,7 +1884,7 @@ class tasklist extends rcube_plugin
 
             // get prepared inline UI for this event object
             if ($ical_objects->method) {
-                $html .= html::div('tasklist-invitebox',
+                $html .= html::div('tasklist-invitebox invitebox boxinformation',
                     $this->itip->mail_itip_inline_ui(
                         $task,
                         $ical_objects->method,
@@ -2394,7 +2394,7 @@ class tasklist extends rcube_plugin
         // get a list of writeable lists to save new tasks to
         if ((!$existing || $is_shared) && $response['action'] == 'rsvp' || $response['action'] == 'import') {
             $lists  = $this->driver->get_lists($mode);
-            $select = new html_select(array('name' => 'tasklist', 'id' => 'itip-saveto', 'is_escaped' => true));
+            $select = new html_select(array('name' => 'tasklist', 'id' => 'itip-saveto', 'is_escaped' => true, 'class' => 'form-control'));
             $select->add('--', '');
 
             foreach ($lists as $list) {