diff --git a/src/App.vue b/src/App.vue
index 3ba256c..86148fe 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -1,25 +1,29 @@
 <template>
   <n-config-provider>
-    <n-split direction="horizontal" :resize-trigger-size="8" v-model:size="editorStore.split">
-      <template #1>
-        <editor v-model:content="editorStore.content" v-model:selection="editorStore.selection"
-          v-model:scroll="editorStore.scroll" :icons="iconStore.icons" :size="editorStore.size" />
-      </template>
-      <template #2>
-        <scroller v-model:scroll="editorStore.scroll">
-          <BSMap :content="editorStore.content" :size="editorStore.size" />
-        </scroller>
-      </template>
-      <template #resize-trigger>
-        <div :class="$style.resizer">
-        </div>
-      </template>
-    </n-split>
+    <div :class="$style.container" :style="{ '--menu-bar-height': '34px' }">
+      <app-menu :class="$style.menu" :items="menuItems" />
+      <n-split :class="$style.main" direction="horizontal" :resize-trigger-size="8" v-model:size="editorStore.split">
+        <template #1>
+          <editor v-model:content="editorStore.content" v-model:selection="editorStore.selection"
+            v-model:scroll="editorStore.scroll" :icons="iconStore.icons" :size="editorStore.size" />
+        </template>
+        <template #2>
+          <scroller v-model:scroll="editorStore.scroll">
+            <BSMap :content="editorStore.content" :size="editorStore.size" />
+          </scroller>
+        </template>
+        <template #resize-trigger>
+          <div :class="$style.resizer" />
+        </template>
+      </n-split>
+    </div>
   </n-config-provider>
 </template>
 
 <script lang="ts" setup>
+import { h } from 'vue';
 import {
+  type DropdownOption,
   NConfigProvider,
   NSplit,
 } from 'naive-ui';
@@ -27,12 +31,67 @@ import {
 import { useEditorStore } from '@/stores/editor';
 import { useIconStore } from '@/stores/icon';
 
+import useDomEvented from '@/composables/useDomEvented';
+
+import AppMenu from './components/AppMenu.vue';
 import Scroller from './components/Scroller.vue';
 import BSMap from './components/BSMap.vue';
 import Editor from './components/Editor.vue';
 
+import SizeSetter from './components/AppMenu/SizeSetter.vue';
+
 const editorStore = useEditorStore();
 const iconStore = useIconStore();
+
+const isFullscreen = useDomEvented(document, 'fullscreenchange', () => !!document.fullscreenElement);
+
+const menuItems: DropdownOption[] = [
+  {
+    label: 'View',
+    key: 'view',
+    children: [
+      {
+        key: 'icon-size',
+        type: 'render',
+        render: () => h(SizeSetter),
+      },
+      { type: 'divider' },
+      {
+        label: () => isFullscreen.value ? 'Leave fullscreen' : 'Enter fullscreen',
+        key: 'fullscreen',
+        props: {
+          onClick: () => {
+            if (isFullscreen.value) {
+              document.exitFullscreen();
+            } else {
+              document.documentElement.requestFullscreen();
+            }
+          },
+        },
+      },
+    ],
+  },
+  {
+    label: 'Help',
+    key: 'help',
+    children: [
+      {
+        label: () => h('a', {
+          href: 'https://github.com/xingrz/rdt-editor/issues/new',
+          target: '_blank',
+        }, 'Feedback'),
+        key: 'feedback',
+      },
+      {
+        label: () => h('a', {
+          href: 'https://github.com/xingrz/rdt-editor',
+          target: '_blank',
+        }, 'About RDT Editor'),
+        key: 'about',
+      },
+    ],
+  },
+];
 </script>
 
 <style lang="scss" module>
@@ -43,6 +102,20 @@ const iconStore = useIconStore();
   overscroll-behavior: none;
 }
 
+.container {
+  display: flex;
+  flex-direction: column;
+  height: 100vh;
+}
+
+.menu {
+  height: var(--menu-bar-height);
+}
+
+.main {
+  height: calc(100vh - var(--menu-bar-height));
+}
+
 .resizer {
   height: 100%;
   background: #cccccc;
diff --git a/src/components/AppMenu.vue b/src/components/AppMenu.vue
new file mode 100644
index 0000000..6da4d1a
--- /dev/null
+++ b/src/components/AppMenu.vue
@@ -0,0 +1,75 @@
+<template>
+  <div :class="$style.menuBar">
+    <n-dropdown v-for="item in props.items" :key="item.key" :class="$style.dropdown" :options="item.children"
+      placement="bottom-start" :show="showingItem == item.key" @select="handleSelect"
+      @clickoutside="handleClickOutside">
+      <n-button quaternary :ref="(el) => bindMenuButton(item.key as string, el as ComponentPublicInstance | null)"
+        @mouseenter="(e) => handleMouseEnter(e, item.key as string)" @click="(e) => handleClick(e, item.key as string)">
+        {{ item.label }}
+      </n-button>
+    </n-dropdown>
+  </div>
+</template>
+
+<script lang="ts" setup>
+import { defineProps, ref, type ComponentPublicInstance } from 'vue';
+import {
+  type DropdownOption,
+  NButton,
+  NDropdown,
+} from 'naive-ui';
+
+const props = defineProps<{
+  items: DropdownOption[];
+}>();
+
+const showingItem = ref<string | null>(null);
+const menuButtons: Record<string, HTMLElement> = {};
+
+function bindMenuButton(key: string, el: ComponentPublicInstance | null): void {
+  if (el) {
+    menuButtons[key] = el.$el;
+  } else {
+    delete menuButtons[key];
+  }
+}
+
+function handleClick(_e: MouseEvent, key: string): void {
+  if (showingItem.value == null) {
+    showingItem.value = key;
+  } else {
+    showingItem.value = null;
+  }
+}
+
+function handleMouseEnter(_e: MouseEvent, key: string): void {
+  if (showingItem.value != null) {
+    menuButtons[showingItem.value]?.blur();
+    showingItem.value = key;
+    menuButtons[showingItem.value]?.focus();
+  }
+}
+
+function handleSelect(): void {
+  showingItem.value = null;
+}
+
+function handleClickOutside(e: MouseEvent): void {
+  if (showingItem.value && menuButtons[showingItem.value]?.contains(e.target as Node)) {
+    return;
+  }
+  showingItem.value = null;
+}
+</script>
+
+<style lang="scss" module>
+.menuBar {
+  display: flex;
+  border-bottom: 1px solid #ddd;
+  box-sizing: border-box;
+}
+
+.dropdown {
+  min-width: 200px;
+}
+</style>
diff --git a/src/components/AppMenu/SizeSetter.vue b/src/components/AppMenu/SizeSetter.vue
new file mode 100644
index 0000000..1ef0fe6
--- /dev/null
+++ b/src/components/AppMenu/SizeSetter.vue
@@ -0,0 +1,27 @@
+<template>
+  <div :class="$style.setter">
+    <span>Icon size</span>
+    <n-slider v-model:value="editorStore.size" :min="20" :max="60" />
+  </div>
+</template>
+
+<script lang="ts" setup>
+import {
+  NSlider,
+} from 'naive-ui';
+
+import { useEditorStore } from '@/stores/editor';
+
+const editorStore = useEditorStore();
+</script>
+
+<style lang="scss" module>
+.setter {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  width: 200px;
+  padding: 8px var(--n-option-prefix-width);
+  font-size: var(--n-font-size);
+}
+</style>
diff --git a/src/components/Editor.vue b/src/components/Editor.vue
index fa613a9..4ea0b12 100644
--- a/src/components/Editor.vue
+++ b/src/components/Editor.vue
@@ -1,7 +1,7 @@
 <template>
   <div ref="holder" :style="{
     width: `100%`,
-    height: `100vh`,
+    height: `100%`,
     lineHeight: `${size}px`,
   }" />
 </template>
diff --git a/src/components/Scroller.vue b/src/components/Scroller.vue
index 133f3ce..13aff29 100644
--- a/src/components/Scroller.vue
+++ b/src/components/Scroller.vue
@@ -33,7 +33,7 @@ function onScroll(): void {
 
 <style lang="scss" module>
 .scroller {
-  height: 100vh;
+  height: 100%;
   overflow-y: scroll;
   overflow-x: hidden;
   background: #f9f9f9;
diff --git a/src/composables/useDomEvented.ts b/src/composables/useDomEvented.ts
new file mode 100644
index 0000000..2af94c2
--- /dev/null
+++ b/src/composables/useDomEvented.ts
@@ -0,0 +1,19 @@
+import { type UnwrapRef, onBeforeUnmount, onMounted, ref } from 'vue';
+
+export default function useDomEvented<T>(target: EventTarget, type: string, getter: () => T) {
+  const value = ref<T>(getter());
+
+  const listener = () => {
+    value.value = getter() as UnwrapRef<T>;
+  };
+
+  onMounted(() => {
+    target.addEventListener(type, listener);
+  });
+
+  onBeforeUnmount(() => {
+    target.removeEventListener(type, listener);
+  });
+
+  return value;
+}