diff --git a/server/server.js b/server/server.js
index b95c07d..ffe2d8c 100644
--- a/server/server.js
+++ b/server/server.js
@@ -649,6 +649,64 @@ async function downloadImage(url, targetPath) {
   }
 }
 
+function guessPrimaryVideo(rootFolder) {
+  const safe = sanitizeRelative(rootFolder);
+  if (!safe) return null;
+
+  const baseDir = path.join(DOWNLOAD_DIR, safe);
+  if (!fs.existsSync(baseDir)) return null;
+
+  let bestRelPath = null;
+  let bestSize = 0;
+
+  const stack = [""];
+  while (stack.length) {
+    const currentRel = stack.pop();
+    const currentDir = path.join(baseDir, currentRel);
+    let dirEntries = [];
+    try {
+      dirEntries = fs.readdirSync(currentDir, { withFileTypes: true });
+    } catch (err) {
+      console.warn(`⚠️ Klasör okunamadı (${currentDir}): ${err.message}`);
+      continue;
+    }
+
+    for (const entry of dirEntries) {
+      const name = entry.name;
+      if (name.startsWith(".")) continue;
+      if (name === INFO_FILENAME) continue;
+
+      const relPath = path.join(currentRel, name);
+      const absPath = path.join(currentDir, name);
+
+      if (entry.isDirectory()) {
+        stack.push(relPath);
+        continue;
+      }
+
+      if (!entry.isFile()) continue;
+
+      const ext = path.extname(name).toLowerCase();
+      if (!VIDEO_EXTS.includes(ext)) continue;
+
+      let size = 0;
+      try {
+        size = fs.statSync(absPath).size;
+      } catch (err) {
+        console.warn(`⚠️ Dosya boyutu alınamadı (${absPath}): ${err.message}`);
+        continue;
+      }
+
+      if (size >= bestSize) {
+        bestSize = size;
+        bestRelPath = relPath;
+      }
+    }
+  }
+
+  return bestRelPath ? bestRelPath.replace(/\\/g, "/") : null;
+}
+
 async function ensureMovieData(
   rootFolder,
   displayName,