diff --git a/frontend/app.js b/frontend/app.js
index 3227e9c..2b6292c 100644
--- a/frontend/app.js
+++ b/frontend/app.js
@@ -19,6 +19,9 @@ let _gtinMappingPendingRefresh = false;
 let _gtinMappingPendingVariantId = null;
 let _gtinMappingPendingRestore = null;  // { drugId, variantId, packId } — auto-select after reload
 let _gtinMappingWaitingForNewDrug = null; // Set of drug IDs before add-drug; resolved on first loadDrugs
+let _highlightedBatchLot = null;   // lot number to highlight after a main-screen scan
+let _highlightedVariantId = null;  // variant the highlighted batch belongs to
+let _highlightClearTimer = null;   // timer to auto-remove the highlight
 
 /** Build a human-readable pack label from pack fields, e.g. "Box of 28" */
 function packLabel(packOrUnitName, packSize) {
@@ -521,6 +524,9 @@ function setupEventListeners() {
             closeModal(e.target);
         }
     });
+
+    // Main-screen barcode scan
+    document.addEventListener('keydown', _onMainScreenKeydown);
 }
 
 // Load drugs from API
@@ -863,11 +869,22 @@ function populateDispensePackSelect(variant) {
     });
 
     if (packCount) packCount.value = '';
+
+    // Auto-select the first available pack
+    if (activePacks.length > 0) {
+        packSelect.value = String(activePacks[0].id);
+    }
+
     if (packPreview) {
         packPreview.textContent = activePacks.length > 0
             ? `Select a pack and whole-number count (${variant.unit} base unit).`
             : `No active packs for this variant.`;
     }
+
+    // Update preview to reflect the auto-selected pack
+    if (activePacks.length > 0) {
+        updateDispenseQuantityFromPack();
+    }
 }
 
 function updateDispenseModeUi() {
@@ -999,13 +1016,16 @@ function renderVariantInventoryDetails(variant, batches) {
             const stocktakeLabel = hasPackState
                 ? `${formatDisplayNumber(batch.current_full_pack_count)} full ${escapeHtml(packLabel(batch.received_pack_unit_name, batch.received_pack_size_snapshot))} + ${formatDisplayNumber(batch.current_loose_base_units)} ${escapeHtml(variant.unit)} loose`
                 : `${formatDisplayNumber(batch.quantity)} ${escapeHtml(variant.unit)}`;
-            const batchCardStyles = expired
-                ? 'padding: 8px; background: #fff1f2; border: 1px solid #f3a6ad; border-radius: 5px; font-size: 0.9em;'
-                : 'padding: 8px; background: #ffffff; border: 1px solid #d8e2ea; border-radius: 5px; font-size: 0.9em;';
+            const isHighlighted = _highlightedBatchLot === batch.batch_number && _highlightedVariantId === variant.id;
+            const batchCardStyles = isHighlighted
+                ? 'padding: 8px; background: #fef9c3; border: 2px solid #f59e0b; border-radius: 5px; font-size: 0.9em;'
+                : expired
+                    ? 'padding: 8px; background: #fff1f2; border: 1px solid #f3a6ad; border-radius: 5px; font-size: 0.9em;'
+                    : 'padding: 8px; background: #ffffff; border: 1px solid #d8e2ea; border-radius: 5px; font-size: 0.9em;';
             const expiryStyles = expired ? 'color: #b91c1c; font-weight: 700;' : 'color: #4b5563;';
 
             return `
-                <div style="${batchCardStyles}">
+                <div style="${batchCardStyles}" data-batch-number="${escapeHtml(batch.batch_number)}" data-variant-id="${variant.id}">
                     <div style="display: flex; justify-content: space-between; gap: 8px; flex-wrap: wrap;">
                         <div style="display: flex; align-items: center; gap: 8px; flex-wrap: wrap;">
                             <strong>${escapeHtml(batch.batch_number)}</strong>
@@ -3341,6 +3361,68 @@ let _preScanFocusedValue = null;  // its value before any scan chars were typed
 const SCAN_MAX_GAP_MS = 50;
 const SCAN_MIN_LENGTH = 20;
 
+// Separate buffer for main-screen scan (does not interfere with delivery modal)
+let _mainScanBuffer = [];
+let _mainScanBufferTimer = null;
+let _mainPreScanFocusedInput = null;
+let _mainPreScanFocusedValue = null;
+
+function _onMainScreenKeydown(e) {
+    // Only act when no modal is open
+    if (document.querySelector('.modal.show')) return;
+
+    const now = Date.now();
+
+    if (e.key === 'Enter') {
+        const raw = _mainScanBuffer.map(x => x.char).join('');
+        _mainScanBuffer = [];
+        if (_mainScanBufferTimer) { clearTimeout(_mainScanBufferTimer); _mainScanBufferTimer = null; }
+
+        if (raw.length >= SCAN_MIN_LENGTH) {
+            e.preventDefault();
+            if (_mainPreScanFocusedInput) {
+                _mainPreScanFocusedInput.value = _mainPreScanFocusedValue || '';
+            }
+            _mainPreScanFocusedInput = null;
+            _mainPreScanFocusedValue = null;
+            handleMainScreenBarcodeScan(raw);
+        }
+        return;
+    }
+
+    if (e.key.length === 1) {
+        const gap = _mainScanBuffer.length > 0 ? now - _mainScanBuffer[_mainScanBuffer.length - 1].time : 0;
+
+        if (_mainScanBuffer.length > 0 && gap > SCAN_MAX_GAP_MS) {
+            _mainScanBuffer = [];
+            _mainPreScanFocusedInput = null;
+            _mainPreScanFocusedValue = null;
+        }
+
+        if (_mainScanBuffer.length === 0) {
+            const active = document.activeElement;
+            if (active && (active.tagName === 'INPUT' || active.tagName === 'TEXTAREA')) {
+                _mainPreScanFocusedInput = active;
+                _mainPreScanFocusedValue = active.value;
+            } else {
+                _mainPreScanFocusedInput = null;
+                _mainPreScanFocusedValue = null;
+            }
+        } else {
+            e.preventDefault();
+        }
+
+        _mainScanBuffer.push({ char: e.key, time: now });
+
+        if (_mainScanBufferTimer) clearTimeout(_mainScanBufferTimer);
+        _mainScanBufferTimer = setTimeout(() => {
+            _mainScanBuffer = [];
+            _mainPreScanFocusedInput = null;
+            _mainPreScanFocusedValue = null;
+        }, 500);
+    }
+}
+
 function _onDeliveryModalKeydown(e) {
     // Only act when the receive delivery modal is open
     if (!document.getElementById('receiveDeliveryModal')?.classList.contains('show')) return;
@@ -3412,6 +3494,82 @@ function _onDeliveryModalKeydown(e) {
     }
 }
 
+async function handleMainScreenBarcodeScan(raw) {
+    const parsed = parseGS1(raw);
+    if (!parsed) {
+        showToast('Barcode not recognised as a GS1 code', 'warning');
+        return;
+    }
+
+    const { gtin, lot } = parsed;
+
+    let mapping = null;
+    try {
+        const resp = await apiCall(`/gtin/${encodeURIComponent(gtin)}`);
+        if (resp.ok) {
+            mapping = await resp.json();
+        } else if (resp.status !== 404) {
+            throw new Error(`Server error ${resp.status}`);
+        }
+    } catch (err) {
+        showToast('Failed to look up barcode: ' + err.message, 'error');
+        return;
+    }
+
+    if (!mapping) {
+        showToast('Unknown barcode — scan it in a delivery first to map it to a drug', 'warning');
+        return;
+    }
+
+    const drugId = mapping.drug_id;
+    const variantId = mapping.drug_variant_id;
+
+    // Expand drug + variant
+    expandedDrugs.add(drugId);
+    expandedVariants.add(variantId);
+
+    // Ensure detail + batch data are loaded
+    await ensureDrugDetailLoaded(drugId);
+    if (!loadedVariantBatches.has(variantId)) {
+        try {
+            const resp = await apiCall(`/variants/${variantId}/batches`);
+            if (resp.ok) loadedVariantBatches.set(variantId, await resp.json());
+        } catch (_) { /* non-fatal */ }
+    }
+
+    // Set highlight
+    if (_highlightClearTimer) { clearTimeout(_highlightClearTimer); _highlightClearTimer = null; }
+    _highlightedBatchLot = lot;
+    _highlightedVariantId = variantId;
+
+    renderDrugs();
+
+    requestAnimationFrame(() => scrollToHighlightedBatch());
+
+    // Auto-clear highlight after 5 seconds
+    _highlightClearTimer = setTimeout(() => {
+        _highlightedBatchLot = null;
+        _highlightedVariantId = null;
+        _highlightClearTimer = null;
+        renderDrugs();
+    }, 5000);
+
+    // Confirm to user
+    const batches = loadedVariantBatches.get(variantId) || [];
+    const found = batches.some(b => b.batch_number === lot);
+    if (found) {
+        showToast(`${mapping.drug_name} ${mapping.variant_strength} — lot ${lot}`, 'success');
+    } else {
+        showToast(`${mapping.drug_name} ${mapping.variant_strength} — lot ${lot} (no active stock)`, 'warning');
+    }
+}
+
+function scrollToHighlightedBatch() {
+    if (!_highlightedBatchLot || _highlightedVariantId == null) return;
+    const el = document.querySelector(`[data-batch-number="${CSS.escape(_highlightedBatchLot)}"][data-variant-id="${_highlightedVariantId}"]`);
+    if (el) el.scrollIntoView({ behavior: 'smooth', block: 'center' });
+}
+
 async function handleBarcodeScan(raw) {
     const parsed = parseGS1(raw);
     if (!parsed) {