diff --git a/app/modules/project/templates/project/inbox.html b/app/modules/project/templates/project/inbox.html
index 9498440..6cd617b 100644
--- a/app/modules/project/templates/project/inbox.html
+++ b/app/modules/project/templates/project/inbox.html
@@ -1,7 +1,7 @@
 {% extends "erp_base.html" %}
 
 {% block head_extra %}
-<link rel="stylesheet" href="/static/project.css?v=20260916p" />
+<link rel="stylesheet" href="/static/project.css?v=20260916q" />
 <link rel="stylesheet" href="/static/vendor/material-symbols/material-symbols.css" />
 {% endblock %}
 
diff --git a/app/modules/project/templates/project/index.html b/app/modules/project/templates/project/index.html
index b37f4fa..96a8029 100644
--- a/app/modules/project/templates/project/index.html
+++ b/app/modules/project/templates/project/index.html
@@ -1,7 +1,7 @@
 {% extends "erp_base.html" %}
 
 {% block head_extra %}
-<link rel="stylesheet" href="/static/project.css?v=20260916p" />
+<link rel="stylesheet" href="/static/project.css?v=20260916q" />
 <link rel="stylesheet" href="/static/vendor/material-symbols/material-symbols.css" />
 {% endblock %}
 
diff --git a/app/modules/project/templates/project/project.html b/app/modules/project/templates/project/project.html
index 3c05214..67e17e0 100644
--- a/app/modules/project/templates/project/project.html
+++ b/app/modules/project/templates/project/project.html
@@ -1,7 +1,7 @@
 {% extends "erp_base.html" %}
 
 {% block head_extra %}
-<link rel="stylesheet" href="/static/project.css?v=20260916p" />
+<link rel="stylesheet" href="/static/project.css?v=20260916q" />
 <!-- 구글 머티리얼 심볼(담당자 아이콘 등) — self-host -->
 <link rel="stylesheet" href="/static/vendor/material-symbols/material-symbols.css" />
 <!-- 타임라인 vis-timeline — self-host -->
diff --git a/app/static/project.css b/app/static/project.css
index b62dfee..1a0dafd 100644
--- a/app/static/project.css
+++ b/app/static/project.css
@@ -170,8 +170,14 @@
    스크롤바 때문(호버해야만 잠깐 보이는 스타일). 여기 자체 스크롤 패널들은
    막대가 항상 보이도록 커스텀 스크롤바를 그린다(윈도우 설정과 무관하게
    고정 표시). */
-.pj-home-side, .pj-home-main, .pj-project-mytasks, .pj-side, .pj-board {
-  scrollbar-width: thin; scrollbar-color: #b9bcc4 #f1f2f4;
+/* 주의: Chromium(크롬/엣지) 121+ 는 scrollbar-width/scrollbar-color 가 지정돼
+   있으면 ::-webkit-scrollbar 커스텀 스타일을 통째로 무시하고 OS 오버레이
+   (자동숨김) 스크롤바로 돌아간다 — 그래서 표준 속성은 ::-webkit-scrollbar 를
+   지원하지 않는 브라우저(Firefox)에만 준다. */
+@supports not selector(::-webkit-scrollbar) {
+  .pj-home-side, .pj-home-main, .pj-project-mytasks, .pj-side, .pj-board {
+    scrollbar-width: thin; scrollbar-color: #b9bcc4 #f1f2f4;
+  }
 }
 .pj-home-side::-webkit-scrollbar, .pj-home-main::-webkit-scrollbar, .pj-project-mytasks::-webkit-scrollbar,
 .pj-side::-webkit-scrollbar, .pj-board::-webkit-scrollbar { width: 9px; height: 9px; }