It's called an "Integration Manager" (singular)

Fixes https://github.com/vector-im/riot-web/issues/11256

This was finally annoying me enough to fix it.

res/css/views/settings/_IntegrationManager.scss

@@ -0,0 +1,44 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_IntegrationManager .mx_Dialog {
+    width: 60%;
+    height: 70%;
+    overflow: hidden;
+    padding: 0px;
+    max-width: initial;
+    max-height: initial;
+}
+
+.mx_IntegrationManager iframe {
+    background-color: #fff;
+    border: 0px;
+    width: 100%;
+    height: 100%;
+}
+
+.mx_IntegrationManager_loading h3 {
+    text-align: center;
+}
+
+.mx_IntegrationManager_error {
+    text-align: center;
+    padding-top: 20px;
+}
+
+.mx_IntegrationManager_error h3 {
+    color: $warning-color;
+}