diff --git a/api/dropbox-sync.js b/api/dropbox-sync.js
index 5963244..bff3157 100644
--- a/api/dropbox-sync.js
+++ b/api/dropbox-sync.js
@@ -10,6 +10,86 @@ function setCors(req, res) {
   applyCors(req, res, 'POST, OPTIONS');
 }
 
+const COLUMN_PATTERNS = {
+  CLASSIFICATION: ['classification'],
+  LONG_DE: ['long', 'description', 'german'],
+  LONG_EN: ['long', 'description', 'english'],
+  SHORT_DE: ['short', 'description', 'german'],
+  SHORT_EN: ['short', 'description', 'english'],
+  DETAILS_DE: ['details', 'german'],
+  DETAILS_EN: ['details', 'english'],
+  INNER_L: ['inner', 'l'],
+  INNER_W: ['inner', 'w'],
+  INNER_H: ['inner', 'h'],
+  OUTER_L: ['outer', 'l'],
+  OUTER_W: ['outer', 'w'],
+  OUTER_H: ['outer', 'h'],
+  UNITS_OUTER: ['units', 'outer'],
+  MOQ: ['moq'],
+  VERIFIED_DIMS: ['verified', 'dims'],
+  VALIDATED_CHECK: ['validated', 'check'],
+  VALIDATED_NOTE: ['validated', 'note'],
+  PRODUCT_TYPE: ['product', 'type'],
+  ITEM_TO_LOGISTIC: ['item', 'logistic'],
+  CPNP_NO: ['cpnp'],
+};
+
+function resolveEditableColumns(headers) {
+  if (!headers || !Array.isArray(headers)) {
+    // Fallback default editable column indices
+    return new Set([
+      9, 10, 11, 28, 33, 43, 44, 45, 48, 49, 50, 64, 65, 66, 67,
+      100, 101, 102, 103, 104, 107,
+      18, 19, 20, 21, 22, 23, 24, 25, 26, 27
+    ]);
+  }
+
+  const h = headers.map(val => String(val || '').toLowerCase());
+  const resolved = {};
+
+  Object.entries(COLUMN_PATTERNS).forEach(([key, patterns]) => {
+    const idx = h.findIndex(headerText =>
+      patterns.every(p => headerText.includes(p.toLowerCase()))
+    );
+    if (idx >= 0) {
+      resolved[key] = idx;
+    }
+  });
+
+  const editableColumns = new Set([
+    resolved.CLASSIFICATION,
+    resolved.LONG_DE,
+    resolved.LONG_EN,
+    resolved.SHORT_DE,
+    resolved.SHORT_EN,
+    resolved.DETAILS_DE,
+    resolved.DETAILS_EN,
+    resolved.INNER_L,
+    resolved.INNER_W,
+    resolved.INNER_H,
+    resolved.OUTER_L,
+    resolved.OUTER_W,
+    resolved.OUTER_H,
+    resolved.UNITS_OUTER,
+    resolved.MOQ,
+    resolved.VERIFIED_DIMS,
+    resolved.VALIDATED_CHECK,
+    resolved.VALIDATED_NOTE,
+    resolved.PRODUCT_TYPE,
+    resolved.ITEM_TO_LOGISTIC,
+    resolved.CPNP_NO
+  ].filter(val => val !== undefined));
+
+  headers.forEach((header, i) => {
+    const headerText = String(header || '').toLowerCase();
+    if (headerText.includes('srp') || headerText.includes('uvp') || headerText.includes('price')) {
+      editableColumns.add(i);
+    }
+  });
+
+  return editableColumns;
+}
+
 export default async function handler(req, res) {
   setCors(req, res);
 
@@ -27,37 +107,68 @@ export default async function handler(req, res) {
       return res.status(405).json({ error: 'Method not allowed' });
     }
 
-    const { rows } = req.body;
+    const { rows, headers } = req.body;
 
     if (!rows || !Array.isArray(rows)) {
       return res.status(400).json({ error: 'Missing rows data' });
     }
 
     const articleNoIdx = 0;
-    // Fetch IDs of ALL products that have manual edits so we don't overwrite them
+    // Fetch data and status of ALL products so we can merge non-editable columns for manually edited ones
     const { data: existingProducts } = await supabase
       .from('products')
-      .select('product_id, status');
+      .select('product_id, data, status');
 
-    // Protect ALL products that are not 'excel' status (i.e. they have manual edits or special status)
-    const manuallyEditedIds = new Set(
-      (existingProducts || [])
-        .filter(p => p.status && p.status !== 'excel')
-        .map(p => p.product_id)
-    );
-
-    // Also protect any product that has history entries — they were edited at some point.
-    // If their status was accidentally reset to 'excel', this restores protection.
+    // Protect any product that has history entries
     const { data: historyProducts } = await supabase
       .from('products_history')
       .select('product_id');
-    (historyProducts || []).forEach(h => manuallyEditedIds.add(h.product_id));
+    const historyIds = new Set((historyProducts || []).map(h => h.product_id));
 
+    const manuallyEditedProducts = new Map();
+    (existingProducts || []).forEach(p => {
+      const isProtected = (p.status && p.status !== 'excel') || historyIds.has(p.product_id);
+      if (isProtected) {
+        manuallyEditedProducts.set(p.product_id, p);
+      }
+    });
+
+    const editableColumns = resolveEditableColumns(headers);
     const productsToUpsert = [];
+
     for (const row of rows) {
       const productId = String(row[articleNoIdx]);
-      // Only add if: new product OR existing but NOT manually edited
-      if (productId && productId.trim() !== '' && !manuallyEditedIds.has(productId)) {
+      if (!productId || productId.trim() === '') continue;
+
+      const manuallyEdited = manuallyEditedProducts.get(productId);
+
+      if (manuallyEdited) {
+        const dbRowData = manuallyEdited.data;
+        if (dbRowData && Array.isArray(dbRowData)) {
+          const mergedData = [...dbRowData];
+          while (mergedData.length < row.length) {
+            mergedData.push(null);
+          }
+          let hasChange = false;
+          for (let i = 0; i < row.length; i++) {
+            if (i >= 100) continue; // Protect virtual columns
+            if (editableColumns.has(i)) continue; // Protect editable columns
+            if (mergedData[i] !== row[i]) {
+              mergedData[i] = row[i];
+              hasChange = true;
+            }
+          }
+          if (hasChange) {
+            productsToUpsert.push({
+              product_id: productId,
+              data: mergedData,
+              status: manuallyEdited.status || 'edited',
+              updated_at: new Date().toISOString()
+            });
+          }
+        }
+      } else {
+        // Normal excel sync
         productsToUpsert.push({
           product_id: productId,
           data: row,
@@ -67,16 +178,20 @@ export default async function handler(req, res) {
       }
     }
 
-    console.log('Upserting', productsToUpsert.length, 'new/updated products to Supabase...');
+    console.log('Upserting/updating', productsToUpsert.length, 'products in Supabase...');
 
-    // We can now use a normal upsert because we filtered out the manual edits
-    const { error } = await supabase
-      .from('products')
-      .upsert(productsToUpsert, { onConflict: 'product_id' });
+    // Chunk upsert updates to avoid payload sizes or API limits
+    const CHUNK_SIZE = 100;
+    for (let i = 0; i < productsToUpsert.length; i += CHUNK_SIZE) {
+      const chunk = productsToUpsert.slice(i, i + CHUNK_SIZE);
+      const { error } = await supabase
+        .from('products')
+        .upsert(chunk, { onConflict: 'product_id' });
 
-    if (error) {
-      console.error('Supabase upsert error:', error);
-      return res.status(500).json({ error: error.message, detail: 'Failed to upsert products' });
+      if (error) {
+        console.error('Supabase upsert error in chunk:', error);
+        return res.status(500).json({ error: error.message, detail: 'Failed to upsert products chunk' });
+      }
     }
 
     return res.json({
diff --git a/data (3).xlsx b/data (3).xlsx
index 06f5dec..9f31dae 100644
Binary files a/data (3).xlsx and b/data (3).xlsx differ
diff --git a/src/App.tsx b/src/App.tsx
index d504cd4..5ecd87e 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -295,7 +295,7 @@ export default function App() {
           const syncRes = await fetch('/api/dropbox-sync', {
             method: 'POST',
             headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({ rows, fileMeta })
+            body: JSON.stringify({ rows, headers, fileMeta })
           });
           
           if (syncRes.ok) {