RoomList2 -> RoomList

res/css/views/rooms/_RoomList.scss

@@ -0,0 +1,25 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+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_RoomList {
+    width: calc(100% - 16px); // 16px of artificial right-side margin (8px is overflowed from the sublists)
+
+    // Create a column-based flexbox for the sublists. That's pretty much all we have to
+    // worry about in this stylesheet.
+    display: flex;
+    flex-direction: column;
+    flex-wrap: nowrap; // let the column overflow
+}