prepare messagePage layout

src/View/ChatPages/messagePage.css

@@ -0,0 +1,18 @@
+/* layout */
+#chat-page #main #message-page .content {
+    padding: 0px;
+
+    overflow: hidden;
+
+    display: grid;
+    grid-template-rows: 1fr var(--control-height);
+}
+
+#message-page #message-container {
+    overflow: auto;
+}
+
+/* composer */
+#message-page #composer {
+    border-top: 1px solid var(--border);
+}

src/View/ChatPages/messagePage.tsx

@@ -1,13 +1,19 @@
+import "./messagePage.css";
+
 import * as React from "bloatless-react";
 
 import ChatViewModel from "../../ViewModel/chatViewModel";
 
 export function MessagePage(chatViewModel: ChatViewModel) {
   return (
-    <div>
+    <div id="message-page">
       <div class="toolbar">
         <span subscribe:innerText={chatViewModel.primaryChannel}></span>
       </div>
+      <div class="content">
+        <div id="message-container"></div>
+        <div id="composer"></div>
+      </div>
     </div>
   );
 }