diff --git a/frontend/lib/dom/comment.ts b/frontend/lib/dom/comment.ts
index 84c827c1..a690ce91 100644
--- a/frontend/lib/dom/comment.ts
+++ b/frontend/lib/dom/comment.ts
@@ -6,7 +6,7 @@ import iconInfoOutlineRounded from "iconify/info-outline-rounded";
 import { Comment } from "../types";
 import { getJWT, decodeJWT, logout, fetchGitHubMeta } from "../auth";
 import { apiEndpoint } from "../const";
-import { groupBy, dateTimeFormatter, isReallyMobile } from "../util";
+import { groupBy, dateTimeFormatter, isMobileLike } from "../util";
 
 let selectedOffset: HTMLElement | null = null;
 
@@ -124,7 +124,7 @@ export const selectOffsetParagraph = async ({
   }
 
   if (
-    (!isReallyMobile() && selectedOffset?.dataset.reviewHasComments) ||
+    (!isMobileLike() && selectedOffset?.dataset.reviewHasComments) ||
     forceOpenCommentsPanel
   ) {
     delete selectedOffset.dataset.reviewFocused;
diff --git a/frontend/lib/util.ts b/frontend/lib/util.ts
index 92d3dd5c..56c1382f 100644
--- a/frontend/lib/util.ts
+++ b/frontend/lib/util.ts
@@ -18,8 +18,6 @@ export const dateTimeFormatter = new Intl.DateTimeFormat("zh-CN", {
   timeStyle: "short",
 });
 
-export function isReallyMobile() {
-  return /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(
-    navigator.userAgent,
-  );
+export function isMobileLike() {
+  return window.innerWidth < 768;
 }