diff --git a/apps/web/src/reader/readerRuntime.test.ts b/apps/web/src/reader/readerRuntime.test.ts
index ee9fb8e..d331867 100644
--- a/apps/web/src/reader/readerRuntime.test.ts
+++ b/apps/web/src/reader/readerRuntime.test.ts
@@ -222,11 +222,12 @@ describe("reader runtime helpers", () => {
     expect(verticalBranch).not.toContain('hidden={!imageSizes[item.page]}');
   });
 
-  it("keeps unloaded CBZ vertical pages visually covered by a page-sized fallback", () => {
+  it("keeps unloaded PDF and CBZ vertical pages visually covered by a page-sized fallback", () => {
     const styles = readFileSync(new URL("../styles/app.css", import.meta.url), "utf8");
 
+    expect(styles).toContain(".pdf-page-frame-vertical > canvas,\n.pdf-page-frame-vertical > .reader-fallback");
     expect(styles).toContain(".comic-page-frame-vertical > img,\n.comic-page-frame-vertical > .reader-fallback");
-    expect(styles).toContain(".comic-page-frame-vertical > .reader-fallback {\n  width: 100%;");
+    expect(styles).toContain(".pdf-page-frame-vertical > .reader-fallback,\n.comic-page-frame-vertical > .reader-fallback {\n  width: 100%;");
     expect(styles).toContain("min-height: inherit");
     expect(styles).toContain("background: #f7f0df");
   });
diff --git a/apps/web/src/styles/app.css b/apps/web/src/styles/app.css
index 7e28046..4f6abbb 100644
--- a/apps/web/src/styles/app.css
+++ b/apps/web/src/styles/app.css
@@ -1114,11 +1114,14 @@ main.app-main-reader .reader-page {
   padding: 0 12px;
 }
 
+.pdf-page-frame-vertical > canvas,
+.pdf-page-frame-vertical > .reader-fallback,
 .comic-page-frame-vertical > img,
 .comic-page-frame-vertical > .reader-fallback {
   grid-area: 1 / 1;
 }
 
+.pdf-page-frame-vertical > .reader-fallback,
 .comic-page-frame-vertical > .reader-fallback {
   width: 100%;
   min-height: inherit;