style the button

src/platform/web/ui/css/themes/element/timeline.css

@@ -85,6 +85,11 @@ limitations under the License.
     justify-self: right;
     margin-top: -12px;
     margin-right: 4px;
+    /* button visuals */
+    border: #ccc 1px solid;
+    height: 24px;
+    background-color: #fff;
+    border-radius: 4px;
 }
 
 .Timeline_messageTime {

src/platform/web/ui/session/room/timeline/common.js

@@ -30,6 +30,6 @@ export function renderMessage(t, vm, body) {
         t.if(vm => !vm.isContinuation, t => t.div({className: `Timeline_messageSender usercolor${vm.avatarColorNumber}`}, vm.displayName)),
         body,
         // should be after body as it is overlayed on top
-        t.button({className: "Timeline_messageOptions"}, "⋮"),
+        t.button({className: "Timeline_messageOptions"}, "⋯"),
     ]);
 }