diff --git a/frontend/index.html b/frontend/index.html
index c67be98..b233c2b 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -1174,7 +1174,7 @@
     </div>
 
     <!-- Scripts -->
-    <script src="/static/js/main.js?v=20260130-2222"></script>
+    <script src="/static/js/main.js?v=4.0"></script>
     <script src="/static/js/trial-periods.js?v=1.3"></script>
     <script src="/static/js/trial-periods-page.js?v=1.6"></script>
 </body>
diff --git a/frontend/js/main.js b/frontend/js/main.js
index 25c01fa..41341f2 100644
--- a/frontend/js/main.js
+++ b/frontend/js/main.js
@@ -61,7 +61,7 @@ function canDelete() {
 }
 
 document.addEventListener("DOMContentLoaded", function () {
-  console.log("CRM System Main JS v3.5 Loaded - " + new Date().toLocaleString());
+  console.log("CRM System Main JS v4.0 Loaded - " + new Date().toLocaleString());
   // 登录守卫
   const token = localStorage.getItem("crmToken");
   if (!token && !window.location.pathname.endsWith("login.html")) {
@@ -3240,76 +3240,56 @@ document.addEventListener("DOMContentLoaded", function () {
       if (!this.files.length) return;
 
       const files = Array.from(this.files);
-      const newBase64Images = [];
+      if (files.length === 0) return;
 
-      for (const file of files) {
-        // 验证是否为图片
-        if (!file.type.startsWith("image/")) {
+      const formData = new FormData();
+      files.forEach(file => {
+        if (file.type.startsWith("image/")) {
+          formData.append("screenshots", file);
+        } else {
           console.warn(`File is not an image: ${file.name}`);
-          continue;
         }
+      });
 
-        // Helper to convert file to base64 with retry
-        const fileToBase64 = async (f, attempt = 1) => {
-          try {
-            return await new Promise((resolve, reject) => {
-              const reader = new FileReader();
-              reader.onload = () => resolve(reader.result);
-              reader.onerror = () => reject(reader.error || new Error("FileReader error"));
-              reader.onabort = () => reject(new Error("File read aborted"));
-              reader.readAsDataURL(f);
-            });
-          } catch (err) {
-            if (attempt < 3 && err.name === "NotReadableError") {
-              console.warn(`Retrying ${f.name} read due to NotReadableError (attempt ${attempt})...`);
-              await new Promise(r => setTimeout(r, 200 * attempt));
-              return fileToBase64(f, attempt + 1);
-            }
-            throw err;
-          }
-        };
-
-        try {
-          console.log(`[v3.5] Processing ${file.name} (${file.size} bytes)...`);
-          const base64 = await fileToBase64(file);
-          newBase64Images.push(base64);
-          console.log(`Successfully converted ${file.name}`);
-        } catch (error) {
-          console.error(`Primary method failed for ${file.name}:`, error);
-
-          // Fallback: arrayBuffer
-          try {
-            console.log(`Trying arrayBuffer fallback for ${file.name}...`);
-            const buffer = await file.arrayBuffer();
-            const bytes = new Uint8Array(buffer);
-            let binary = "";
-            const chunkSize = 8192;
-            for (let i = 0; i < bytes.length; i += chunkSize) {
-              const chunk = bytes.slice(i, i + chunkSize);
-              binary += String.fromCharCode.apply(null, chunk);
-            }
-            const b64 = `data:${file.type};base64,${btoa(binary)}`;
-            newBase64Images.push(b64);
-            console.log(`Fallback successful for ${file.name}`);
-          } catch (fallbackError) {
-            console.error(`Both methods failed for ${file.name}:`, fallbackError);
-            alert(`无法读取文件 "${file.name}"。\n这种情况通常是浏览器或系统文件锁定导致的。\n\n建议尝试：\n1. 刷新页面后再试\n2. 使用浏览器的“无痕模式”\n3. 确认文件没有被其他软件打开`);
-          }
-        }
+      if (formData.getAll("screenshots").length === 0) {
+        alert("请选择有效的图片文件");
+        return;
       }
 
-      if (type === "create") {
-        createUploadedScreenshots = [
-          ...createUploadedScreenshots,
-          ...newBase64Images,
-        ];
-        renderScreenshotPreviews("create", createUploadedScreenshots);
-      } else {
-        editUploadedScreenshots = [
-          ...editUploadedScreenshots,
-          ...newBase64Images,
-        ];
-        renderScreenshotPreviews("edit", editUploadedScreenshots);
+      try {
+        console.log(`[v4.0] Uploading ${files.length} files to server...`);
+        const response = await authenticatedFetch("/api/upload", {
+          method: "POST",
+          body: formData,
+          // Note: When sending FormData, the browser automatically sets the correct Content-Type with boundary
+        });
+
+        if (response.ok) {
+          const result = await response.json();
+          const newBase64Images = result.filePaths || [];
+          console.log(`Successfully uploaded ${newBase64Images.length} images`);
+
+          if (type === "create") {
+            createUploadedScreenshots = [
+              ...createUploadedScreenshots,
+              ...newBase64Images,
+            ];
+            renderScreenshotPreviews("create", createUploadedScreenshots);
+          } else {
+            editUploadedScreenshots = [
+              ...editUploadedScreenshots,
+              ...newBase64Images,
+            ];
+            renderScreenshotPreviews("edit", editUploadedScreenshots);
+          }
+        } else {
+          const errorText = await response.text();
+          console.error("Upload failed:", errorText);
+          alert("图片上传失败，请稍后重试。");
+        }
+      } catch (error) {
+        console.error("Error during upload:", error);
+        alert("上传过程出错，可能是浏览器权限问题或网络连接中断。");
       }
 
       // 清除 input，以便再次选择同一张图片