diff --git a/app/modules/project/templates/project/inbox.html b/app/modules/project/templates/project/inbox.html
index 2e71266..81acc30 100644
--- a/app/modules/project/templates/project/inbox.html
+++ b/app/modules/project/templates/project/inbox.html
@@ -45,5 +45,5 @@
   {% endif %}
 </div>
 
-<script src="/static/project.js?v=20260916j" defer></script>
+<script src="/static/project.js?v=20260916k" defer></script>
 {% endblock %}
diff --git a/app/modules/project/templates/project/index.html b/app/modules/project/templates/project/index.html
index 30360e9..7d6203e 100644
--- a/app/modules/project/templates/project/index.html
+++ b/app/modules/project/templates/project/index.html
@@ -376,5 +376,5 @@
 <script>
   window.PJ_COLORS = {{ ["#4573d2","#37a3a3","#62a420","#e8a33d","#e8384f","#aa62e3","#f06a6a","#5a6772"] | tojson }};
 </script>
-<script src="/static/project.js?v=20260916j" defer></script>
+<script src="/static/project.js?v=20260916k" defer></script>
 {% endblock %}
diff --git a/app/modules/project/templates/project/project.html b/app/modules/project/templates/project/project.html
index a4b77ea..87b0deb 100644
--- a/app/modules/project/templates/project/project.html
+++ b/app/modules/project/templates/project/project.html
@@ -379,5 +379,5 @@
 </script>
 
 <script src="/static/vendor/vis-timeline/vis-timeline-graph2d.min.js"></script>
-<script src="/static/project.js?v=20260916j" defer></script>
+<script src="/static/project.js?v=20260916k" defer></script>
 {% endblock %}
diff --git a/app/static/project.js b/app/static/project.js
index bcd1a53..b786432 100644
--- a/app/static/project.js
+++ b/app/static/project.js
@@ -2079,15 +2079,34 @@
       }
     }
 
+    // 삽입 전 원본 크기를 확인해, 설명란보다 넓으면 90%로 줄여서 넣는다
+    // (그대로 넣으면 크기조절 핸들이 설명란 밖으로 삐져나간다).
+    function naturalImageSize(file) {
+      return new Promise(function (resolve) {
+        const url = URL.createObjectURL(file);
+        const img = new Image();
+        img.onload = function () { URL.revokeObjectURL(url); resolve({ width: img.naturalWidth }); };
+        img.onerror = function () { URL.revokeObjectURL(url); resolve(null); };
+        img.src = url;
+      });
+    }
+
     async function insertImageFile(file) {
       if (!taskId) { alert("먼저 저장한 뒤 이미지를 추가할 수 있습니다."); return; }
       const fd = new FormData();
       fd.append("file", file);
       try {
-        const res = await fetch("/project/api/tasks/" + taskId + "/attachments", { method: "POST", body: fd });
+        const results = await Promise.all([
+          naturalImageSize(file),
+          fetch("/project/api/tasks/" + taskId + "/attachments", { method: "POST", body: fd }),
+        ]);
+        const dims = results[0], res = results[1];
         if (!res.ok) { let m = res.statusText; try { m = (await res.json()).detail; } catch (_) {} throw new Error(m); }
         const data = await res.json();
-        insertHtmlAtCursor('<img src="/project/api/attachments/' + data.attachment.id + '/inline" alt="">');
+        const boxW = box.clientWidth || 0;
+        const widthAttr = (dims && dims.width && boxW && dims.width > boxW)
+          ? ' width="' + Math.round(boxW * 0.9) + '"' : "";
+        insertHtmlAtCursor('<img src="/project/api/attachments/' + data.attachment.id + '/inline" alt=""' + widthAttr + '>');
       } catch (e) { alert("이미지 업로드 실패: " + e.message); }
     }