diff --git a/klausur-service/backend/grid_editor_api.py b/klausur-service/backend/grid_editor_api.py
index 6cbfe5f..697f7d4 100644
--- a/klausur-service/backend/grid_editor_api.py
+++ b/klausur-service/backend/grid_editor_api.py
@@ -309,8 +309,16 @@ def _build_zone_grid(
     zone_index: int,
     img_w: int,
     img_h: int,
+    global_columns: Optional[List[Dict]] = None,
 ) -> Dict[str, Any]:
-    """Build columns, rows, cells for a single zone from its words."""
+    """Build columns, rows, cells for a single zone from its words.
+
+    Args:
+        global_columns: If provided, use these pre-computed column boundaries
+            instead of detecting columns per zone.  Used for content zones so
+            that all content zones (above/between/below boxes) share the same
+            column structure.  Box zones always detect columns independently.
+    """
     if not zone_words:
         return {
             "columns": [],
@@ -321,8 +329,8 @@ def _build_zone_grid(
 
     # Cluster rows first (needed for column alignment analysis)
     rows = _cluster_rows(zone_words)
-    # Cluster columns by left-edge alignment
-    columns = _cluster_columns_by_alignment(zone_words, zone_w, rows)
+    # Use global columns if provided, otherwise detect per zone
+    columns = global_columns if global_columns else _cluster_columns_by_alignment(zone_words, zone_w, rows)
 
     if not columns or not rows:
         return {
@@ -476,13 +484,40 @@ async def build_grid(session_id: str):
                     content_x, content_y, content_w, content_h, boxes
                 )
 
+                # --- Global column detection across ALL content zones ---
+                # Content zones share the same table structure (the table
+                # spans the full page, boxes are overlaid on top).  Detect
+                # columns once from all content-zone words so that narrow
+                # columns (page refs, markers) visible in only one zone
+                # are applied consistently everywhere.
+                all_content_words: List[Dict] = []
+                for pz in page_zones:
+                    if pz.zone_type == "content":
+                        all_content_words.extend(
+                            _words_in_zone(all_words, pz.y, pz.height, pz.x, pz.width)
+                        )
+
+                global_columns = None
+                if all_content_words:
+                    global_rows = _cluster_rows(all_content_words)
+                    global_columns = _cluster_columns_by_alignment(
+                        all_content_words, content_w, global_rows,
+                    )
+                    logger.info(
+                        "build-grid session %s: global columns from %d content words → %d columns",
+                        session_id, len(all_content_words), len(global_columns),
+                    )
+
                 for pz in page_zones:
                     zone_words = _words_in_zone(
                         all_words, pz.y, pz.height, pz.x, pz.width
                     )
+                    # Content zones use global columns; box zones detect independently
+                    cols_override = global_columns if pz.zone_type == "content" else None
                     grid = _build_zone_grid(
                         zone_words, pz.x, pz.y, pz.width, pz.height,
                         pz.index, img_w, img_h,
+                        global_columns=cols_override,
                     )
 
                     zone_entry: Dict[str, Any] = {