Add basic styling

src/App.module.css

@@ -0,0 +1,111 @@
+/*
+Copyright 2021 New Vector 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.
+*/
+
+.page {
+  margin: 0 auto;
+  max-width: 960px;
+  display: flex;
+  flex-direction: column;
+}
+
+.page input {
+  padding: 8px 4px;
+  font-size: 16px;
+  border-radius: 4px;
+  border: 1px solid #888;
+}
+
+.page input, .page button {
+  display: block;
+  margin-top: 16px;
+}
+
+.room {
+  position: fixed;
+  display: flex;
+  flex-direction: column;
+  width: 100vw;
+  height: 100vh;
+  overflow: hidden;
+}
+
+.header {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  height: 64px;
+
+}
+
+.joinRoom {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+}
+
+.joinRoom ul {
+  margin-top: 0;
+  padding-left: 0;
+}
+
+.joinRoom button {
+  border: none;
+  background: green;
+  color: white;
+  font-size: 16px;
+  font-weight: bold;
+  padding: 8px 16px;
+  border-radius: 4px;
+  cursor: pointer;
+}
+
+.joinRoom button:hover, .joinRoom button:active {
+  background: darkgreen;
+}
+
+.centerMessage {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+}
+
+.centerMessage p {
+  display: block;
+}
+
+.roomContainer {
+  display: flex;
+  flex: 1;
+}
+
+.participant {
+  display: flex;
+  position: relative;
+  flex: 1;
+}
+
+.participant video {
+  width: 100%;
+  height: 100%;
+}
+
+.participantLabel {
+  position: absolute;
+  bottom: 0;
+  right: 0;
+  padding: 8px 16px;
+  background: rgba(0, 0, 0, 0.2);
+}