diff --git a/src/routes/op.ts b/src/routes/op.ts
index 43af09d..1a02257 100644
--- a/src/routes/op.ts
+++ b/src/routes/op.ts
@@ -197,6 +197,11 @@ opRouter.get(
         res.status(404).send('폴더를 찾을 수 없습니다.')
         return
       }
+      // 영상은 2단계(서브) 폴더에만 둔다. 1단계 폴더는 컨테이너 전용.
+      if (folder.parentId === null) {
+        res.status(400).send('영상은 하위 폴더에서만 추가할 수 있습니다.')
+        return
+      }
       const videoId = typeof req.query.id === 'string' ? req.query.id : null
       const video = videoId ? getVideo(videoId) : null
       res.render('op/editor', {
@@ -239,6 +244,7 @@ opRouter.post(
     try {
       const folder = getFolderByPath(collectFolderSegments(req.params))
       if (!folder) throw new Error('폴더를 찾을 수 없습니다.')
+      if (folder.parentId === null) throw new Error('영상은 하위 폴더에서만 추가할 수 있습니다.')
       const file = req.file
       if (!file) throw new Error('파일이 없습니다.')
       const title = pickStr(req.body?.title).trim() || file.originalname
@@ -284,6 +290,7 @@ opRouter.post(
     try {
       const folder = getFolderByPath(collectFolderSegments(req.params))
       if (!folder) throw new Error('폴더를 찾을 수 없습니다.')
+      if (folder.parentId === null) throw new Error('영상은 하위 폴더에서만 추가할 수 있습니다.')
       const url = pickStr(req.body.url).trim()
       const title = pickStr(req.body.title).trim() || undefined
       if (!url) throw new Error('URL 을 입력해 주세요.')
diff --git a/views/folder.ejs b/views/folder.ejs
index 89d160b..a5b7b54 100644
--- a/views/folder.ejs
+++ b/views/folder.ejs
@@ -28,32 +28,34 @@
       <h1>📁 <%= breadcrumb.join(' / ') %></h1>
     </section>
 
-    <% if (subFolders && subFolders.length > 0) { %>
+    <% if (!isSubFolder) { %>
       <section class="folderGrid">
-        <% subFolders.forEach(function (sf) { %>
+        <% if (!subFolders || subFolders.length === 0) { %>
+          <p class="muted">아직 하위 폴더가 없습니다.</p>
+        <% } %>
+        <% (subFolders || []).forEach(function (sf) { %>
           <a class="folderCard" href="/folder/<%= folderPathEnc %>/<%= encodeURIComponent(sf.name) %>">
             <span class="folderIcon">📁</span>
             <span class="folderName"><%= sf.name %></span>
           </a>
         <% }) %>
       </section>
-    <% } %>
-
-    <section class="videoGrid">
-      <% if (videos.length === 0 && (!subFolders || subFolders.length === 0)) { %>
-        <p class="muted">이 폴더에 영상이 없습니다.</p>
-      <% } %>
-      <% videos.forEach(function (v) { %>
-        <%
-          var shareUrl = '/video/' + folderPathEnc + '/' + encodeURIComponent(v.id)
+    <% } else { %>
+      <section class="videoGrid">
+        <% if (videos.length === 0) { %>
+          <p class="muted">이 폴더에 영상이 없습니다.</p>
+        <% } %>
+        <% videos.forEach(function (v) {
+             var shareUrl = '/video/' + folderPathEnc + '/' + encodeURIComponent(v.id)
         %>
-        <a class="videoCard" href="<%= shareUrl %>"
-           data-video-id="<%= v.id %>" data-share-url="<%= shareUrl %>">
-          <div class="videoThumb">▶</div>
-          <div class="videoTitle"><%= v.title %></div>
-        </a>
-      <% }) %>
-    </section>
+          <a class="videoCard" href="<%= shareUrl %>"
+             data-video-id="<%= v.id %>" data-share-url="<%= shareUrl %>">
+            <div class="videoThumb">▶</div>
+            <div class="videoTitle"><%= v.title %></div>
+          </a>
+        <% }) %>
+      </section>
+    <% } %>
   </main>
 
   <div class="ctxMenu" id="ctxMenu" hidden>
diff --git a/views/op/folder.ejs b/views/op/folder.ejs
index 2cc328c..562a483 100644
--- a/views/op/folder.ejs
+++ b/views/op/folder.ejs
@@ -25,18 +25,20 @@
       </div>
       <div class="dashboardActions">
         <% if (!isSubFolder) { %>
-          <button type="button" class="secondaryButton" id="addSubFolderBtn">하위 폴더 추가</button>
-        <% } %>
-        <a class="primaryButton" href="<%= editorHref %>">영상 추가</a>
-        <% if (isSubFolder) { %>
+          <button type="button" class="primaryButton" id="addSubFolderBtn">하위 폴더 추가</button>
+        <% } else { %>
+          <a class="primaryButton" href="<%= editorHref %>">영상 추가</a>
           <a class="primaryButton" href="<%= playlistHref %>">플레이리스트 추가</a>
         <% } %>
       </div>
     </section>
 
-    <% if (!isSubFolder && subFolders && subFolders.length > 0) { %>
+    <% if (!isSubFolder) { %>
       <section class="folderGrid" id="subFolderGrid">
-        <% subFolders.forEach(function (sf) { %>
+        <% if (!subFolders || subFolders.length === 0) { %>
+          <p class="muted">아직 하위 폴더가 없습니다. 우측 상단에서 하위 폴더를 추가하세요. (영상은 하위 폴더 안에서만 추가할 수 있습니다.)</p>
+        <% } %>
+        <% (subFolders || []).forEach(function (sf) { %>
           <div class="folderCard adminFolder" data-folder-id="<%= sf.id %>" data-name="<%= sf.name %>">
             <a class="folderCardLink" href="/op/folder/<%= folderPathEnc %>/<%= encodeURIComponent(sf.name) %>">
               <span class="folderIcon">📁</span>
@@ -45,28 +47,28 @@
           </div>
         <% }) %>
       </section>
+    <% } else { %>
+      <section class="videoGrid" id="videoGrid">
+        <% if (videos.length === 0) { %>
+          <p class="muted">이 폴더에 영상이 없습니다. 우측 상단에서 영상을 추가하세요.</p>
+        <% } %>
+        <% videos.forEach(function (v) {
+             var shareUrl = '/video/' + folderPathEnc + '/' + encodeURIComponent(v.id)
+        %>
+          <div class="videoCard adminVideo"
+               data-id="<%= v.id %>"
+               data-video-id="<%= v.id %>"
+               data-title="<%= v.title %>"
+               data-share-url="<%= shareUrl %>">
+            <div class="videoThumb">▶</div>
+            <div class="videoTitle"><%= v.title %></div>
+            <% if (v.sourceType === 'youtube') { %>
+              <div class="muted">YouTube</div>
+            <% } %>
+          </div>
+        <% }) %>
+      </section>
     <% } %>
-
-    <section class="videoGrid" id="videoGrid">
-      <% if (videos.length === 0 && (isSubFolder || !subFolders || subFolders.length === 0)) { %>
-        <p class="muted">이 폴더에 영상이 없습니다. 우측 상단에서 영상을 추가하세요.</p>
-      <% } %>
-      <% videos.forEach(function (v) {
-           var shareUrl = '/video/' + folderPathEnc + '/' + encodeURIComponent(v.id)
-      %>
-        <div class="videoCard adminVideo"
-             data-id="<%= v.id %>"
-             data-video-id="<%= v.id %>"
-             data-title="<%= v.title %>"
-             data-share-url="<%= shareUrl %>">
-          <div class="videoThumb">▶</div>
-          <div class="videoTitle"><%= v.title %></div>
-          <% if (v.sourceType === 'youtube') { %>
-            <div class="muted">YouTube</div>
-          <% } %>
-        </div>
-      <% }) %>
-    </section>
   </main>
 
   <div class="ctxMenu" id="ctxMenu" hidden>
@@ -90,19 +92,21 @@
     </div>
   </div>
 
-  <div class="modalOverlay" id="addSubFolderModal" hidden>
-    <div class="modalCard">
-      <h2>하위 폴더 추가</h2>
-      <label>
-        <span>폴더 이름</span>
-        <input type="text" id="addSubFolderInput" autofocus />
-      </label>
-      <div class="modalActions">
-        <button type="button" class="secondaryButton" id="addSubFolderCancel">취소</button>
-        <button type="button" class="primaryButton" id="addSubFolderConfirm">생성</button>
+  <% if (!isSubFolder) { %>
+    <div class="modalOverlay" id="addSubFolderModal" hidden>
+      <div class="modalCard">
+        <h2>하위 폴더 추가</h2>
+        <label>
+          <span>폴더 이름</span>
+          <input type="text" id="addSubFolderInput" autofocus />
+        </label>
+        <div class="modalActions">
+          <button type="button" class="secondaryButton" id="addSubFolderCancel">취소</button>
+          <button type="button" class="primaryButton" id="addSubFolderConfirm">생성</button>
+        </div>
       </div>
     </div>
-  </div>
+  <% } %>
 
   <script>
     window.__OP__ = {