diff --git a/pos/static/css/pos-ui.css b/pos/static/css/pos-ui.css
index 32f6652..0bf19ea 100644
--- a/pos/static/css/pos-ui.css
+++ b/pos/static/css/pos-ui.css
@@ -819,3 +819,43 @@ input:disabled, select:disabled, textarea:disabled {
   background: var(--color-surface-1, #1a1a1a);
   border-bottom: 2px solid var(--color-primary, #F5A623);
 }
+
+/* Enhanced depth layers for both themes */
+[data-theme="modern"] {
+  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
+  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
+  --shadow-lg: 0 8px 24px rgba(0,0,0,0.5);
+  --shadow-xl: 0 16px 48px rgba(0,0,0,0.6);
+}
+[data-theme="industrial"] {
+  --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
+  --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
+  --shadow-lg: 0 8px 24px rgba(0,0,0,0.6);
+  --shadow-xl: 0 16px 48px rgba(0,0,0,0.7);
+}
+
+/* Smooth theme transition (only on properties that don't cause flash) */
+.card, .glass-card, .btn, .icon-btn, .kpi-card, .alert-card, .meli-card {
+  transition: background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
+}
+
+/* Improved text rendering in dark */
+body {
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+/* Focus visible for accessibility */
+*:focus-visible {
+  outline: 2px solid var(--color-primary, #F5A623);
+  outline-offset: 2px;
+}
+
+/* Reduced motion preference */
+@media (prefers-reduced-motion: reduce) {
+  *, *::before, *::after {
+    animation-duration: 0.01ms !important;
+    animation-iteration-count: 1 !important;
+    transition-duration: 0.01ms !important;
+  }
+}
diff --git a/pos/static/js/customers.js b/pos/static/js/customers.js
index 34caada..ec22861 100644
--- a/pos/static/js/customers.js
+++ b/pos/static/js/customers.js
@@ -94,6 +94,8 @@ const Customers = (() => {
         }
     }
 
+    var selectedCustomers = new Set();
+
     function renderCustomerRow(c) {
         const tier = tierMap[c.price_tier] || 'Mostrador';
         const tClass = tierClass[c.price_tier] || 'mostrador';
@@ -104,7 +106,9 @@ const Customers = (() => {
         const creditClass = usedPct >= 80 ? 'none' : usedPct >= 60 ? 'low' : '';
         const num = String(c.id).padStart(5, '0');
         const selClass = (currentCustomer && currentCustomer.id === c.id) ? 'selected' : '';
-        return '<tr class="' + selClass + '" onclick="Customers.selectCustomer(' + c.id + ')">' +
+        const isChecked = selectedCustomers.has(c.id) ? 'checked' : '';
+        return '<tr class="' + selClass + '">' +
+            '<td onclick="event.stopPropagation();"><input type="checkbox" ' + isChecked + ' onchange="Customers.toggleCustomerSelection(' + c.id + ')"></td>' +
             '<td class="cell-num">' + num + '</td>' +
             '<td>' +
                 '<div class="cell-name">' + (c.name || '') + '</div>' +
@@ -801,6 +805,41 @@ const Customers = (() => {
         showPaymentModal, closePayment, recordPayment,
     };
 
+    // Bulk selection
+    publicApi.toggleCustomerSelection = function(id) {
+        if (selectedCustomers.has(id)) selectedCustomers.delete(id);
+        else selectedCustomers.add(id);
+        updateBulkToolbar();
+    };
+    publicApi.toggleSelectAll = function() {
+        var cb = document.getElementById('selectAllCustomers');
+        var allChecked = cb.checked;
+        if (customersVS && customersVS.data) {
+            customersVS.data.forEach(function(c) {
+                if (allChecked) selectedCustomers.add(c.id);
+                else selectedCustomers.delete(c.id);
+            });
+            customersVS.refresh();
+        }
+        updateBulkToolbar();
+    };
+    function updateBulkToolbar() {
+        var container = document.getElementById('customersBulkToolbar');
+        if (!container) return;
+        var count = selectedCustomers.size;
+        if (count === 0) { container.innerHTML = ''; return; }
+        container.innerHTML = renderBulkToolbar(count,
+            '<button class="btn btn--primary btn--sm" onclick="Customers.featureProximamente(\'Exportar seleccionados\')">📥 Exportar</button>' +
+            '<button class="btn btn--ghost btn--sm" onclick="Customers.clearSelection()">Limpiar</button>'
+        );
+    }
+    publicApi.clearSelection = function() {
+        selectedCustomers.clear();
+        document.getElementById('selectAllCustomers').checked = false;
+        if (customersVS) customersVS.refresh();
+        updateBulkToolbar();
+    };
+
     // Expose globally for inline HTML onclick handlers
     window.Customers = publicApi;
     return publicApi;
diff --git a/pos/static/js/inventory.js b/pos/static/js/inventory.js
index 847e569..e898132 100644
--- a/pos/static/js/inventory.js
+++ b/pos/static/js/inventory.js
@@ -1314,6 +1314,15 @@
             html += '<span id="imgUploadStatus" style="display:block;margin-top:4px;font-size:var(--text-caption);color:var(--color-text-muted);"></span>';
             html += '</div>';
 
+            // Action buttons
+            html += '<div style="display:flex;gap:8px;justify-content:center;margin-bottom:16px;padding-bottom:16px;border-bottom:1px solid var(--color-border);">';
+            html += '<button class="btn btn--ghost btn--sm" onclick="showProductTimeline(' + data.id + ')">📅 Timeline</button>';
+            if (data.image_url) {
+                html += '<button class="btn btn--ghost btn--sm" onclick="showImageCompare(\'' + esc(data.image_url) + '\')">🖼️ Comparar</button>';
+            }
+            html += '<button class="btn btn--ghost btn--sm" onclick="viewHistory(' + data.id + ')">📜 Historial</button>';
+            html += '</div>';
+
             // Product info header
             html += '<div style="display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:16px;padding-bottom:16px;border-bottom:1px solid var(--color-border);">';
             html += '<div><span style="font-size:var(--text-caption);color:var(--color-text-muted);text-transform:uppercase;display:block;">ID Inventario</span><strong style="font-family:var(--font-mono);">' + data.id + '</strong></div>';
@@ -1535,9 +1544,76 @@
     window.autoMatchCompat = autoMatchCompat;
     window.removeCompat = removeCompat;
 
+    // ─── Product Timeline ──────────────────────────────────────────
+    window.showProductTimeline = function(itemId) {
+        var modal = document.getElementById('productTimelineModal');
+        var body = document.getElementById('productTimelineBody');
+        body.innerHTML = '<div style="padding:20px;"><div class="skeleton skeleton--text"></div><div class="skeleton skeleton--text-sm"></div></div>';
+        modal.classList.add('is-open');
+
+        apiFetch(API + '/items/' + itemId + '/history').then(function(data) {
+            var history = (data && data.data) ? data.data : [];
+            var html = '<div class="timeline">';
+            html += '<div class="timeline__item"><div class="timeline__dot timeline__dot--green"></div><div class="timeline__content"><div class="timeline__date">Producto creado</div><div class="timeline__title">Registro inicial en inventario</div></div></div>';
+            history.forEach(function(h) {
+                var color = h.quantity > 0 ? 'timeline__dot--green' : (h.quantity < 0 ? 'timeline__dot--red' : 'timeline__dot--blue');
+                var title = (h.type || 'Movimiento') + ' · ' + (h.quantity > 0 ? '+' : '') + h.quantity + ' unidades';
+                html += '<div class="timeline__item"><div class="timeline__dot ' + color + '"></div><div class="timeline__content">' +
+                    '<div class="timeline__date">' + esc(h.date) + ' · ' + esc(h.employee) + '</div>' +
+                    '<div class="timeline__title">' + esc(title) + '</div>' +
+                    (h.notes ? '<div class="timeline__desc">' + esc(h.notes) + '</div>' : '') +
+                    '</div></div>';
+            });
+            html += '</div>';
+            body.innerHTML = html;
+        });
+    };
+
+    // ─── Image Comparator ──────────────────────────────────────────
+    window.showImageCompare = function(imageUrl) {
+        var modal = document.getElementById('imageCompareModal');
+        document.getElementById('imgCompareNew').src = imageUrl + '?t=' + Date.now();
+        document.getElementById('imgCompareOld').src = imageUrl + '?t=' + (Date.now() - 1);
+        modal.classList.add('is-open');
+        setTimeout(function() { if (typeof initImageComparator === 'function') initImageComparator('#imgCompareContainer'); }, 100);
+    };
+
+    // ─── Infinite Scroll ───────────────────────────────────────────
+    var _infiniteScrollInstance = null;
+    function setupInfiniteScroll() {
+        if (_infiniteScrollInstance) _infiniteScrollInstance.disconnect();
+        var sentinel = document.createElement('div');
+        sentinel.id = 'inventoryScrollSentinel';
+        sentinel.style.cssText = 'height:1px;';
+        var wrapper = document.querySelector('.table-wrapper');
+        if (wrapper) wrapper.appendChild(sentinel);
+        _infiniteScrollInstance = new InfiniteScroll({
+            sentinelParent: wrapper,
+            onLoad: function(done) {
+                if (!currentSearch && currentPage < (window._inventoryTotalPages || 999)) {
+                    loadItems(currentPage + 1);
+                }
+                if (done) done();
+            }
+        });
+    }
+
+    // ─── Saved Filters ─────────────────────────────────────────────
+    function renderSavedFilters() {
+        var container = document.getElementById('savedFiltersContainer');
+        if (!container) return;
+        SavedFilters.renderChips('savedFiltersContainer', function(filters) {
+            if (filters.search) {
+                var el = document.getElementById('productSearch');
+                if (el) { el.value = filters.search; loadItems(1, filters.search); }
+            }
+        });
+    }
+
     // =====================================================================
     //  INIT — load stock on page load
     // =====================================================================
 
     loadItems(1);
+    renderSavedFilters();
 })();
diff --git a/pos/templates/customers.html b/pos/templates/customers.html
index a0a6a92..c3e1c03 100644
--- a/pos/templates/customers.html
+++ b/pos/templates/customers.html
@@ -306,9 +306,11 @@
 
           <!-- Table -->
           <div class="table-wrap themed-scrollbar">
+            <div id="customersBulkToolbar"></div>
             <table class="customers-table" id="customersTable">
               <thead>
                 <tr>
+                  <th><input type="checkbox" id="selectAllCustomers" onclick="Customers.toggleSelectAll()"></th>
                   <th>#</th>
                   <th>Nombre</th>
                   <th class="hide-mobile">RFC</th>
diff --git a/pos/templates/inventory.html b/pos/templates/inventory.html
index ffaf1bf..2e1dd67 100644
--- a/pos/templates/inventory.html
+++ b/pos/templates/inventory.html
@@ -280,6 +280,7 @@
              =================================================================== -->
         <div class="tab-panel is-active" id="panel-stock" role="tabpanel">
 
+          <div id="savedFiltersContainer" style="margin-bottom:var(--space-2);"></div>
           <div class="toolbar">
             <div class="search-box">
               <svg viewBox="0 0 24 24" stroke-linecap="round"><circle cx="11" cy="11" r="8"/><line x1="21" y1="21" x2="16.65" y2="16.65"/></svg>