diff --git a/app/src/asset/index.ts b/app/src/asset/index.ts
index 7448c0f1f..7ca8d9541 100644
--- a/app/src/asset/index.ts
+++ b/app/src/asset/index.ts
@@ -163,7 +163,7 @@ export class Asset extends Model {
             <span id="findMsg" class="b3-button b3-button--small b3-button--cancel"></span>
         </div>  <!-- findbar -->
         <div id="secondaryToolbar" class="secondaryToolbar fn__hidden doorHangerRight b3-menu">
-          <div id="secondaryToolbarButtonContainer">
+          <div id="secondaryToolbarButtonContainer" class="b3-menu__items">
             <button id="pdfLight" class="secondaryToolbarButton b3-menu__item toggled">
               <svg class="b3-menu__icon"><use xlink:href="#iconLight"></use></svg> 
               <span class="b3-menu__label">${window.siyuan.languages.themeLight}</span>
diff --git a/app/src/assets/scss/pdf/_pdf.scss b/app/src/assets/scss/pdf/_pdf.scss
index 0a2931781..e1638fb29 100644
--- a/app/src/assets/scss/pdf/_pdf.scss
+++ b/app/src/assets/scss/pdf/_pdf.scss
@@ -337,7 +337,10 @@
   top: 36px;
   overflow: auto;
   -webkit-overflow-scrolling: touch;
-  max-height: 60vh;
+
+  .b3-menu__items {
+    max-height: 60vh;
+  }
 }
 
 #secondaryToolbarButtonContainer.hiddenScrollModeButtons > .scrollModeButtons,