diff --git a/apps/ely-show/src/slideshow/start.rs b/apps/ely-show/src/slideshow/start.rs
index 30af92f..311f5ae 100644
--- a/apps/ely-show/src/slideshow/start.rs
+++ b/apps/ely-show/src/slideshow/start.rs
@@ -82,7 +82,7 @@ fn copy(
 
 fn options(display: &Rc<dyn PlatformDisplay>) -> WindowOptions {
     WindowOptions {
-        window_bounds: Some(WindowBounds::Fullscreen(display.bounds())),
+        window_bounds: Some(WindowBounds::Windowed(display.bounds())),
         display_id: Some(display.id()),
         titlebar: None,
         focus: true,
@@ -102,6 +102,8 @@ pub fn show_window(
     Ok(match presenter {
         true => cx
             .open_window(options(display), |window, cx| {
+                // Hides the menu bar and Dock over the show.
+                window.toggle_simple_fullscreen();
                 let view = cx.new(|cx| Presenter::new(show, cx));
                 window.focus(&view.read(cx).focus.clone(), cx);
                 view
@@ -109,6 +111,7 @@ pub fn show_window(
             .into(),
         false => cx
             .open_window(options(display), |window, cx| {
+                window.toggle_simple_fullscreen();
                 let view = cx.new(|cx| Audience::new(show, cx));
                 window.focus(&view.read(cx).focus.clone(), cx);
                 view
diff --git a/tasks/TASKS.md b/tasks/TASKS.md
index fb7536f..9acde4b 100644
--- a/tasks/TASKS.md
+++ b/tasks/TASKS.md
@@ -197,3 +197,4 @@
 - [ ] R2.17 ElyPDF（用户报）：编辑文字时报“这种字体画不出‘V’”，而所改文字里没有 V；改字对应的文字块须与面板所示一致
 - [x] R2.18 官网（用户定）：下载一律指向 GitHub 的 v0.1.x 发布页，不直接链 DMG — R1 截图文案死代码（连同 screen() 与截图一并删去）；R2 PASS；已上线
 - [ ] R2.19 发布 0.1.1：版本号、打包、GitHub Release、官网指向新发布页
+- [ ] R2.20 ElyShow：放映图层一次回复超过 64 MB 帧上限（大屏上 4 张以上图层的幻灯片报 “layers pass 67107840 bytes”，放映起不来）