diff --git a/assets/styles.css b/assets/styles.css
index f2b9260..c651f5c 100644
--- a/assets/styles.css
+++ b/assets/styles.css
@@ -290,8 +290,8 @@ button { cursor: pointer; }
 .toast.show { opacity: 1; transform: translateY(0); }
 .mobile-menu { display: none; }
 
-/* EG-BIM Q&A list layout */
-.qa-list-page { max-width: 100%; overflow-x: hidden; background: #fff; }
+/* EG-BIM support page layout */
+.qa-list-page, .egbim-page { max-width: 100%; overflow-x: hidden; background: #fff; }
 .qa-list-page .site-header { position: absolute; top: 0; right: 0; left: 0; z-index: 10; height: 88px; border-bottom: 0; background: transparent; color: #fff; }
 .qa-list-page .header-inner { max-width: none; padding: 0 48px; }
 .qa-list-page .brand { color: #fff; font-size: 29px; letter-spacing: -.04em; }
@@ -305,18 +305,18 @@ button { cursor: pointer; }
 .qa-list-page .login-link [data-auth-name] { display: none; }
 .qa-list-page .user-icon { border-color: #fff; }
 .qa-list-page .user-icon::after { border-color: #fff; }
-.qa-list-page .page-hero { position: relative; display: block; min-height: 482px; height: 482px; overflow: hidden; background: radial-gradient(circle at 53% 47%, rgba(17, 129, 178, .68) 0, rgba(17, 129, 178, .2) 20%, transparent 42%), radial-gradient(circle at 13% 35%, rgba(11, 92, 133, .58) 0, transparent 28%), radial-gradient(circle at 88% 18%, rgba(23, 76, 113, .35) 0, transparent 30%), linear-gradient(115deg, #061c2a 0%, #06121c 52%, #030509 100%); }
-.qa-list-page .page-hero::before { position: absolute; inset: 0; content: ''; opacity: .22; background-image: radial-gradient(circle, rgba(255,255,255,.75) 0 2px, transparent 3px), linear-gradient(28deg, transparent 48%, rgba(137,211,239,.45) 49%, transparent 50%), linear-gradient(151deg, transparent 48%, rgba(137,211,239,.3) 49%, transparent 50%); background-position: 8% 30%, 0 0, 0 0; background-size: 170px 135px, 240px 190px, 310px 230px; }
-.qa-list-page .hero-inner { position: relative; z-index: 1; padding: 190px 24px 0; text-align: center; }
-.qa-list-page .hero-kicker { display: none; }
-.qa-list-page .page-hero h1 { margin: 0 0 4px; color: #fff; font-size: 70px; font-weight: 700; letter-spacing: -.07em; }
-.qa-list-page .page-hero p { color: #fff; font-size: 20px; font-weight: 500; }
-.qa-list-page .sub-nav { position: absolute; right: 0; bottom: 0; left: 0; z-index: 2; background: rgba(0, 10, 17, .84); }
-.qa-list-page .sub-nav-inner { width: 100%; max-width: none; }
-.qa-list-page .sub-nav a { flex: 1 1 50%; padding: 18px 12px; color: #fff; font-size: 16px; font-weight: 700; }
-.qa-list-page .sub-nav a[aria-current='page'] { background: rgba(0, 121, 116, .5); color: #ffc400; }
-.qa-list-page .sub-nav a.disabled-tab { cursor: default; }
-.qa-list-page .sub-nav a.disabled-tab:hover { background: transparent; color: #fff; }
+.qa-list-page .page-hero, .egbim-page .page-hero { position: relative; display: block; min-height: 482px; height: 482px; overflow: hidden; background: radial-gradient(circle at 53% 47%, rgba(17, 129, 178, .68) 0, rgba(17, 129, 178, .2) 20%, transparent 42%), radial-gradient(circle at 13% 35%, rgba(11, 92, 133, .58) 0, transparent 28%), radial-gradient(circle at 88% 18%, rgba(23, 76, 113, .35) 0, transparent 30%), linear-gradient(115deg, #061c2a 0%, #06121c 52%, #030509 100%); }
+.qa-list-page .page-hero::before, .egbim-page .page-hero::before { position: absolute; inset: 0; content: ''; opacity: .22; background-image: radial-gradient(circle, rgba(255,255,255,.75) 0 2px, transparent 3px), linear-gradient(28deg, transparent 48%, rgba(137,211,239,.45) 49%, transparent 50%), linear-gradient(151deg, transparent 48%, rgba(137,211,239,.3) 49%, transparent 50%); background-position: 8% 30%, 0 0, 0 0; background-size: 170px 135px, 240px 190px, 310px 230px; }
+.qa-list-page .hero-inner, .egbim-page .hero-inner { position: relative; z-index: 1; padding: 190px 24px 0; text-align: center; }
+.qa-list-page .hero-kicker, .egbim-page .hero-kicker { display: none; }
+.qa-list-page .page-hero h1, .egbim-page .page-hero h1 { margin: 0 0 4px; color: #fff; font-size: 70px; font-weight: 700; letter-spacing: -.07em; }
+.qa-list-page .page-hero p, .egbim-page .page-hero p { color: #fff; font-size: 20px; font-weight: 500; }
+.qa-list-page .sub-nav, .egbim-page .sub-nav { position: absolute; right: 0; bottom: 0; left: 0; z-index: 2; background: rgba(0, 10, 17, .84); }
+.qa-list-page .sub-nav-inner, .egbim-page .sub-nav-inner { width: 100%; max-width: none; }
+.qa-list-page .sub-nav a, .egbim-page .sub-nav a { flex: 1 1 50%; padding: 18px 12px; color: #fff; font-size: 16px; font-weight: 700; }
+.qa-list-page .sub-nav a[aria-current='page'], .egbim-page .sub-nav a[aria-current='page'] { background: rgba(0, 121, 116, .5); color: #ffc400; }
+.qa-list-page .sub-nav a.disabled-tab, .egbim-page .sub-nav a.disabled-tab { cursor: default; }
+.qa-list-page .sub-nav a.disabled-tab:hover, .egbim-page .sub-nav a.disabled-tab:hover { background: transparent; color: #fff; }
 .qa-list-page .page-shell { max-width: none; padding: 51px 10px 62px; }
 .qa-list-heading { margin: 0 0 40px; text-align: center; }
 .qa-list-heading h1 { margin: 0; font-size: 30px; line-height: 1.35; letter-spacing: -.06em; }
@@ -358,12 +358,12 @@ button { cursor: pointer; }
   .qa-list-page .brand { font-size: 21px; }
   .qa-list-page .brand-mark { width: 29px; height: 22px; font-size: 23px; }
   .qa-list-page .header-tools { gap: 12px; }
-  .qa-list-page .page-hero { min-height: 390px; height: 390px; }
-  .qa-list-page .hero-inner { padding-top: 145px; }
-  .qa-list-page .page-hero h1 { font-size: 52px; }
-  .qa-list-page .page-hero p { font-size: 16px; }
-  .qa-list-page .sub-nav-inner { max-width: none; }
-  .qa-list-page .sub-nav a { padding: 14px 10px; font-size: 14px; }
+  .qa-list-page .page-hero, .egbim-page .page-hero { min-height: 390px; height: 390px; }
+  .qa-list-page .hero-inner, .egbim-page .hero-inner { padding-top: 145px; }
+  .qa-list-page .page-hero h1, .egbim-page .page-hero h1 { font-size: 52px; }
+  .qa-list-page .page-hero p, .egbim-page .page-hero p { font-size: 16px; }
+  .qa-list-page .sub-nav-inner, .egbim-page .sub-nav-inner { max-width: none; }
+  .qa-list-page .sub-nav a, .egbim-page .sub-nav a { padding: 14px 10px; font-size: 14px; }
   .qa-list-page .page-shell { padding: 39px 14px 55px; }
   .qa-list-heading { margin-bottom: 28px; }
   .qa-list-heading h1 { font-size: 26px; }
diff --git a/egbim/detail.html b/egbim/detail.html
index 38dd2f2..44f5df3 100644
--- a/egbim/detail.html
+++ b/egbim/detail.html
@@ -1,8 +1,8 @@
 <!doctype html>
 <html lang="ko">
-<head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><title>문의 상세 | EG-BIM Q&amp;A</title><link rel="stylesheet" href="../assets/styles.css"></head>
+<head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><title>문의 상세 | EG-BIM Q&amp;A</title><link rel="stylesheet" href="../assets/styles.css?v=20260921-4"></head>
 <body>
-  <main><section class="page-hero"><div class="hero-inner"><span class="hero-kicker">EG-BIM SUPPORT</span><h1>Q&amp;A</h1><p>EG-BIM 관련 문의하기</p></div></section>
+  <main class="egbim-page"><section class="page-hero"><div class="hero-inner"><span class="hero-kicker">EG-BIM SUPPORT</span><h1>Q&amp;A</h1><p>EG-BIM 관련 문의하기</p></div><nav class="sub-nav" aria-label="EG-BIM 지원 메뉴"><div class="sub-nav-inner"><a href="index.html" aria-current="page">문의하기(Q&amp;A)</a><a href="#" aria-disabled="true" class="disabled-tab">원격지원</a></div></nav></section>
     <section class="page-shell" id="detail"><div class="section-heading"><div><h2>문의 상세</h2><p>문의 내용과 답변을 확인할 수 있습니다.</p></div><a class="button button-primary" href="write.html">문의 등록</a></div><article class="detail-card"><div class="detail-head"><div class="detail-title-line"><h2><span class="category" data-detail-category>문의</span> <span data-detail-title>문의 제목</span></h2><span class="status review" data-detail-status>문의접수</span></div><div class="detail-meta"><span data-detail-date>2026-09-17</span><span data-detail-author>작성자</span><span data-detail-company>회사</span><span data-detail-department>부서</span><span data-detail-secret hidden>🔒 비밀글</span></div></div><div class="detail-body" data-detail-content></div><div class="attachments"><h3>첨부파일</h3><span class="help-text">첨부된 파일이 없습니다.</span></div><div class="detail-actions"><a class="button button-outline" href="index.html">목록</a><a class="button button-outline" href="write.html">문의 등록</a></div></article><section class="comment-box"><h3>답변 <span id="commentCount">0</span></h3><div id="comments"></div></section><div class="form-footer"><button class="button button-outline" id="backButton" type="button">목록으로</button></div></section>
   </main><script src="config.js?v=20260921-3"></script><script src="app.js?v=20260921-3"></script>
 </body></html>
diff --git a/egbim/write.html b/egbim/write.html
index 56c248f..e45ec4d 100644
--- a/egbim/write.html
+++ b/egbim/write.html
@@ -1,8 +1,8 @@
 <!doctype html>
 <html lang="ko">
-<head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><title>문의 등록 | EG-BIM Q&amp;A</title><link rel="stylesheet" href="../assets/styles.css"></head>
+<head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><title>문의 등록 | EG-BIM Q&amp;A</title><link rel="stylesheet" href="../assets/styles.css?v=20260921-4"></head>
 <body>
-  <main><section class="page-hero"><div class="hero-inner"><span class="hero-kicker">EG-BIM SUPPORT</span><h1>Q&amp;A</h1><p>EG-BIM 관련 문의하기</p></div></section>
+  <main class="egbim-page"><section class="page-hero"><div class="hero-inner"><span class="hero-kicker">EG-BIM SUPPORT</span><h1>Q&amp;A</h1><p>EG-BIM 관련 문의하기</p></div><nav class="sub-nav" aria-label="EG-BIM 지원 메뉴"><div class="sub-nav-inner"><a href="index.html" aria-current="page">문의하기(Q&amp;A)</a><a href="#" aria-disabled="true" class="disabled-tab">원격지원</a></div></nav></section>
     <section class="page-shell"><div class="section-heading"><div><h2>문의 등록</h2><p>로그인한 사용자 정보로 문의가 등록됩니다.</p></div></div><div class="form-notice" data-auth-state>로그인 상태를 확인하고 있습니다.</div><div class="form-error" id="formError" role="alert"></div><form id="qaForm" novalidate><div class="form-card" id="writeFields"><div class="form-row"><label class="form-label" for="category">구분 <span class="required">*</span></label><div class="form-control"><select class="select" id="category" required><option value="">선택해주세요</option><option>오류문의</option><option>개선문의</option><option>일반문의</option></select></div></div><div class="form-row"><label class="form-label" for="title">제목 <span class="required">*</span></label><div class="form-control"><input class="input" id="title" type="text" maxlength="100" placeholder="문의 제목을 입력해주세요" required></div></div><div class="form-row"><span class="form-label">공개 설정</span><div class="form-control"><label class="check"><input id="secret" type="checkbox"> 비밀글로 등록</label></div></div><div class="form-row"><label class="form-label" for="content">내용 <span class="required">*</span></label><div class="form-control column"><textarea class="textarea" id="content" placeholder="문의 내용을 작성해주세요" required></textarea><span class="help-text">개인정보, 비밀번호, 인증번호 등 민감한 정보는 입력하지 마세요.</span></div></div><div class="form-row"><label class="form-label" for="attachment">첨부파일</label><div class="form-control column"><input class="file-input" id="attachment" type="file" multiple><span class="help-text">파일은 presigned URL을 통해 qa_cdn 버킷에 저장됩니다. 파일당 최대 30MB</span></div></div></div><div class="form-footer"><a class="button button-outline" href="index.html">취소</a><button class="button button-primary" id="submitButton" type="submit">문의 등록</button></div></form></section>
   </main><div id="toast" class="toast" role="status" aria-live="polite"></div><script src="config.js?v=20260921-3"></script><script src="app.js?v=20260921-3"></script>
 </body></html>