diff --git a/src/components/AppShell.jsx b/src/components/AppShell.jsx
index 82e1fe4..4236833 100644
--- a/src/components/AppShell.jsx
+++ b/src/components/AppShell.jsx
@@ -87,8 +87,8 @@ class AppSidebar extends PureComponent {
           disablePadding
           sx={{
             flexGrow: 1,
-            display: 'flex',
-            flexDirection: { xs: 'row', lg: 'column' },
+            display: { xs: 'flex', lg: 'block' },
+            flexDirection: 'row',
             alignItems: 'center',
             height: { xs: '100%', lg: 'auto' },
             overflowX: { xs: 'auto', lg: 'visible' },
@@ -104,6 +104,8 @@ class AppSidebar extends PureComponent {
               <ListItemButton
                 key={path}
                 type="button"
+                aria-label={label}
+                title={label}
                 selected={active}
                 onMouseDown={(e) => e.preventDefault()}
                 onClick={() => {
@@ -131,7 +133,7 @@ class AppSidebar extends PureComponent {
                   borderRadius: { xs: 1, lg: 0 },
                   width: { xs: 'auto', lg: '100%' },
                   height: { xs: '100%', lg: 'auto' },
-                  px: { xs: 1.25, sm: 1.5 },
+                  px: { xs: active ? 1.25 : 1, sm: active ? 1.5 : 1.25, md: 1.5 },
                   py: { xs: 0.75, sm: 1, lg: 1.25 },
                   borderLeft: { xs: 'none', lg: '3px solid transparent' },
                   borderBottom: { xs: '3px solid transparent', lg: 'none' },
@@ -141,7 +143,8 @@ class AppSidebar extends PureComponent {
                   '& .MuiListItemIcon-root': {
                     color: 'inherit',
                     minWidth: { xs: 'auto', lg: 36 },
-                    mr: { xs: 0.75, lg: 0 },
+                    mr: active ? { xs: 0.75, lg: 0 } : { xs: 0, md: 0.75, lg: 0 },
+                    justifyContent: 'center',
                   },
                   '&:hover': {
                     bgcolor: theme.nav.itemHover,
@@ -172,7 +175,10 @@ class AppSidebar extends PureComponent {
                     fontWeight: active ? 600 : 500,
                     noWrap: true,
                   }}
-                  sx={{ m: 0 }}
+                  sx={{
+                    m: { xs: 0, lg: 'initial' },
+                    display: active ? 'block' : { xs: 'none', md: 'block' },
+                  }}
                 />
               </ListItemButton>
             );
@@ -239,25 +245,34 @@ class AppSubNav extends PureComponent {
       <Box
         component="nav"
         aria-label="Unternavigation"
-        sx={{
-          width: { xs: 60, sm: 72, md: SUB_NAV_WIDTH },
+        sx={(theme) => ({
+          width: { xs: '100%', sm: 72, md: SUB_NAV_WIDTH },
           flexShrink: 0,
           display: 'flex',
-          flexDirection: 'column',
+          flexDirection: { xs: 'row', sm: 'column' },
           alignItems: 'center',
-          gap: 1.5,
+          gap: { xs: 1, sm: 1.5 },
           position: 'sticky',
           top: { xs: 52, sm: 56, lg: 0 },
+          zIndex: { xs: 1090, sm: 'auto' },
           alignSelf: 'flex-start',
           height: {
-            xs: 'calc(var(--df-vh, 100vh) - 52px)',
+            xs: 'auto',
             sm: 'calc(var(--df-vh, 100vh) - 56px)',
             lg: 'var(--df-vh, 100vh)',
           },
-          py: { xs: 2, lg: 4 },
-          ml: { xs: 1, sm: 2, lg: 3 },
-          mr: { xs: 1, sm: 1.5, lg: 2 },
-        }}
+          py: { xs: 0.75, sm: 2, lg: 4 },
+          px: { xs: 1.5, sm: 0 },
+          ml: { xs: 0, sm: 2, lg: 3 },
+          mr: { xs: 0, sm: 1.5, lg: 2 },
+          overflowX: { xs: 'auto', sm: 'visible' },
+          scrollbarWidth: 'none',
+          '&::-webkit-scrollbar': { display: 'none' },
+          bgcolor: { xs: theme.nav?.mainBackground || 'background.default', sm: 'transparent' },
+          borderBottom: { xs: '1px solid', sm: 'none' },
+          borderColor: { xs: 'divider', sm: 'transparent' },
+          boxSizing: 'border-box',
+        })}
       >
         {subNav.map(({ segment, label, title, help, icon: Icon }) => {
           const active = segment === activeSub;
@@ -266,6 +281,7 @@ class AppSubNav extends PureComponent {
             <ButtonBase
               key={segment || 'index'}
               type="button"
+              title={label}
               aria-label={label}
               aria-current={active ? 'page' : undefined}
               disableRipple
@@ -290,15 +306,17 @@ class AppSubNav extends PureComponent {
                 navigate(segment ? `${activeNav}/${segment}` : activeNav);
               }}
               sx={(theme) => ({
-                width: { xs: 60, sm: 72, md: SUB_NAV_WIDTH },
-                py: 1,
-                px: 0.5,
+                width: { xs: 'auto', sm: 72, md: SUB_NAV_WIDTH },
+                py: { xs: 0.5, sm: 1 },
+                px: { xs: active ? 1.25 : 0.75, sm: 0.5 },
                 borderRadius: 2,
                 display: 'flex',
-                flexDirection: 'column',
+                flexDirection: { xs: 'row', sm: 'column' },
                 alignItems: 'center',
                 justifyContent: 'center',
-                gap: 0.5,
+                gap: { xs: active ? 0.75 : 0, sm: 0.5 },
+                flexShrink: 0,
+                whiteSpace: 'nowrap',
                 color: active
                   ? theme.nav?.itemActiveAccent || NAV_ITEM_ACTIVE_ACCENT
                   : theme.palette.text.secondary,
@@ -314,18 +332,19 @@ class AppSubNav extends PureComponent {
               })}
             >
               <HelpBadge title={title || label} help={help} placement="right">
-                <Icon sx={{ fontSize: { xs: 24, sm: 28, md: 32 } }} />
+                <Icon sx={{ fontSize: { xs: 20, sm: 28, md: 32 } }} />
               </HelpBadge>
               {label ? (
                 <Typography
                   variant="caption"
                   noWrap
                   sx={{
-                    fontSize: { xs: '0.62rem', sm: '0.68rem' },
+                    fontSize: { xs: '0.75rem', sm: '0.68rem' },
                     fontWeight: 500,
                     lineHeight: 1.2,
                     textAlign: 'center',
                     maxWidth: '100%',
+                    display: active ? 'block' : { xs: 'none', sm: 'block' },
                   }}
                 >
                   {label}
@@ -358,7 +377,7 @@ export default function AppShell() {
       <Box
         sx={{
           display: 'flex',
-          flexDirection: 'row',
+          flexDirection: { xs: 'column', sm: 'row' },
           flexGrow: 1,
           minWidth: 0,
         }}
diff --git a/src/components/manifest/ManifestForm.jsx b/src/components/manifest/ManifestForm.jsx
index 7bb56bf..fb0c8b9 100644
--- a/src/components/manifest/ManifestForm.jsx
+++ b/src/components/manifest/ManifestForm.jsx
@@ -17,7 +17,7 @@ import artikelAutomat, { getArticle } from '../../automats/artikelAutomat';
 import entityAutomat from '../../automats/entityAutomat';
 import supplierAutomat from '../../automats/supplierAutomat';
 import companyAutomat, { selectCompanyTaxrate } from '../../automats/companyAutomat';
-import { netFromGross, getArticleGross } from '../../utils/price';
+import { netFromGross, grossFromNet, getArticleGross } from '../../utils/price';
 import {
   buildManifestBody,
   restoreAttachmentsFromApi,
@@ -421,10 +421,11 @@ class ManifestForm extends PureComponent {
 
         if (field === 'gross') {
           const taxVal = parseNum(line.tax ?? line.taxrate) ?? 0;
+          const rebateVal = parseNum(line.rebate) ?? 0;
           const grossNum = parseNum(value);
           let updatedNet = line.net;
           if (grossNum != null) {
-            const netNum = netFromGross(grossNum, taxVal);
+            const netNum = netFromGross(grossNum, taxVal, rebateVal);
             if (netNum != null) {
               updatedNet = String(netNum);
             }
@@ -441,11 +442,12 @@ class ManifestForm extends PureComponent {
 
         if (field === 'net' || field === 'netprice') {
           const taxVal = parseNum(line.tax ?? line.taxrate) ?? 0;
+          const rebateVal = parseNum(line.rebate) ?? 0;
           const netNum = parseNum(value);
           let updatedGross = line.gross;
           if (netNum != null) {
-            const grossNum = Math.round((netNum * (1 + taxVal / 100) + Number.EPSILON) * 100) / 100;
-            updatedGross = String(grossNum);
+            const grossNum = grossFromNet(netNum, taxVal, rebateVal);
+            updatedGross = grossNum != null ? String(grossNum) : '';
           } else if (value === '') {
             updatedGross = '';
           }
@@ -460,11 +462,12 @@ class ManifestForm extends PureComponent {
 
         if (field === 'tax' || field === 'taxrate') {
           const taxNum = parseNum(value) ?? 0;
+          const rebateVal = parseNum(line.rebate) ?? 0;
           const netNum = parseNum(line.net ?? line.netprice);
           let updatedGross = line.gross;
           if (netNum != null) {
-            const grossNum = Math.round((netNum * (1 + taxNum / 100) + Number.EPSILON) * 100) / 100;
-            updatedGross = String(grossNum);
+            const grossNum = grossFromNet(netNum, taxNum, rebateVal);
+            updatedGross = grossNum != null ? String(grossNum) : '';
           }
           return {
             ...line,
@@ -475,6 +478,22 @@ class ManifestForm extends PureComponent {
           };
         }
 
+        if (field === 'rebate') {
+          const rebateNum = parseNum(value) ?? 0;
+          const taxVal = parseNum(line.tax ?? line.taxrate) ?? 0;
+          const netNum = parseNum(line.net ?? line.netprice);
+          let updatedGross = line.gross;
+          if (netNum != null) {
+            const grossNum = grossFromNet(netNum, taxVal, rebateNum);
+            updatedGross = grossNum != null ? String(grossNum) : '';
+          }
+          return {
+            ...line,
+            rebate: value,
+            gross: updatedGross,
+          };
+        }
+
         return {
           ...line,
           [field]: value,
@@ -508,13 +527,15 @@ class ManifestForm extends PureComponent {
                   : '';
             const netNum = parseNum(netVal);
             const taxNum = parseNum(taxVal);
+            const rebateNum = parseNum(l.rebate) ?? 0;
             const artGross = getArticleGross(art, taxNum ?? 0);
             let grossVal = '';
-            if (artGross != null) {
+            if (artGross != null && rebateNum === 0) {
               grossVal = String(artGross);
             } else if (netNum != null) {
-              const g = Math.round((netNum * (1 + (taxNum ?? 0) / 100) + Number.EPSILON) * 100) / 100;
-              grossVal = String(g);
+              grossVal = String(grossFromNet(netNum, taxNum ?? 0, rebateNum));
+            } else if (artGross != null) {
+              grossVal = String(Math.round((artGross * (1 - rebateNum / 100) + Number.EPSILON) * 100) / 100);
             }
             const normTax = selectCompanyTaxrate() != null ? String(selectCompanyTaxrate()) : '19';
             const finalTax =
@@ -640,13 +661,15 @@ class ManifestForm extends PureComponent {
           : normTax;
     const netNum = parseNum(netVal);
     const taxNum = parseNum(taxVal);
+    const rebateNum = parseNum(targetLine.rebate) ?? 0;
     const artGross = getArticleGross(article, taxNum ?? 0);
     let grossVal = '';
-    if (artGross != null) {
+    if (artGross != null && rebateNum === 0) {
       grossVal = String(artGross);
     } else if (netNum != null) {
-      const g = Math.round((netNum * (1 + (taxNum ?? 0) / 100) + Number.EPSILON) * 100) / 100;
-      grossVal = String(g);
+      grossVal = String(grossFromNet(netNum, taxNum ?? 0, rebateNum));
+    } else if (artGross != null) {
+      grossVal = String(Math.round((artGross * (1 - rebateNum / 100) + Number.EPSILON) * 100) / 100);
     }
 
     this.setState((prev) => ({
diff --git a/src/components/manifest/ManifestFormLine.jsx b/src/components/manifest/ManifestFormLine.jsx
index 9277da7..57fee87 100644
--- a/src/components/manifest/ManifestFormLine.jsx
+++ b/src/components/manifest/ManifestFormLine.jsx
@@ -19,11 +19,13 @@ import SearchIcon from '@mui/icons-material/Search';
 import LinkOffOutlinedIcon from '@mui/icons-material/LinkOffOutlined';
 import { getFirstVal, parseNum, LINE_COLUMNS } from './manifestConfig';
 import ArticlePhoto from '../article/ArticlePhoto';
-import { formatPrice } from '../../utils/price';
+import { formatPrice, grossFromNet } from '../../utils/price';
 import { primaryPrice, priceBrutto } from '../../utils/articleDetail';
 import artikelAutomat, { createArticleSelector, getArticle } from '../../automats/artikelAutomat';
 import { artikelDetailPath } from '../article/articleRoute';
 import { BrandLabel } from '../brand';
+import { articleSupplierAutomat } from '../../automats/articleDetailAutomat';
+import { selectCompanyTaxrate } from '../../automats/companyAutomat';
 import {
   BORDER,
 } from '../../colors';
@@ -35,6 +37,7 @@ class ManifestFormLine extends PureComponent {
     this.state = {
       cachedArticle: sku ? getArticle(sku) : null,
       loadingArticle: false,
+      fallbackSuppliers: [],
     };
     this.handleRemove = this.handleRemove.bind(this);
     this.handleBlur = this.handleBlur.bind(this);
@@ -64,14 +67,18 @@ class ManifestFormLine extends PureComponent {
 
   componentWillUnmount() {
     this.unsubArticle?.();
+    this.unsubSupplier?.();
   }
 
   subscribeArticle(sku) {
     this.unsubArticle?.();
     this.unsubArticle = null;
+    this.unsubSupplier?.();
+    this.unsubSupplier = null;
+
     if (!sku) {
-      if (this.state.cachedArticle || this.state.loadingArticle) {
-        this.setState({ cachedArticle: null, loadingArticle: false });
+      if (this.state.cachedArticle || this.state.loadingArticle || this.state.fallbackSuppliers?.length) {
+        this.setState({ cachedArticle: null, loadingArticle: false, fallbackSuppliers: [] });
       }
       return;
     }
@@ -99,6 +106,15 @@ class ManifestFormLine extends PureComponent {
         ...(art ? { loadingArticle: false } : {}),
       };
     });
+
+    // Fallback: subscribe to articleSupplierAutomat if cachedArticle doesn't have suppliers
+    if (!current?.suppliers?.length) {
+      const supKey = articleSupplierAutomat.key(sku);
+      this.unsubSupplier = supKey.subscribe(this, (item) => ({
+        fallbackSuppliers: Array.isArray(item?.data) ? item.data : [],
+      }));
+      void articleSupplierAutomat.load(sku).catch(() => {});
+    }
   }
 
   handleRemove() {
@@ -235,8 +251,9 @@ class ManifestFormLine extends PureComponent {
       } else if (id === 'gross') {
         const netNum = parseNum(line.netprice ?? line.net);
         const taxNum = parseNum(line.taxrate ?? line.tax) ?? 0;
+        const rebateNum = parseNum(line.rebate) ?? 0;
         if (netNum != null) {
-          val = String(Math.round((netNum * (1 + taxNum / 100) + Number.EPSILON) * 100) / 100);
+          val = String(grossFromNet(netNum, taxNum, rebateNum));
         }
       }
     }
@@ -375,6 +392,41 @@ class ManifestFormLine extends PureComponent {
           : null)
         : null;
 
+      const suppliers =
+        Array.isArray(cachedArticle.suppliers) && cachedArticle.suppliers.length > 0
+          ? cachedArticle.suppliers
+          : (this.state.fallbackSuppliers ?? []);
+
+      const topSupplier =
+        suppliers.find((s) => s.sort === 0) ??
+        (suppliers.length > 0
+          ? [...suppliers].sort((a, b) => (Number(a.sort) || 0) - (Number(b.sort) || 0))[0]
+          : null);
+
+      const ekNetto =
+        topSupplier?.price?.net != null
+          ? Number(topSupplier.price.net)
+          : topSupplier?.netPrice != null
+            ? Number(topSupplier.netPrice)
+            : topSupplier?.net != null
+              ? Number(topSupplier.net)
+              : null;
+
+      const ekTaxRate =
+        topSupplier?.price?.taxRate != null
+          ? Number(topSupplier.price.taxRate)
+          : topSupplier?.taxRate != null
+            ? Number(topSupplier.taxRate)
+            : parseNum(this.props.line?.taxrate ?? this.props.line?.tax) ?? selectCompanyTaxrate() ?? 19;
+
+      const ekBrutto =
+        ekNetto != null
+          ? Math.round((ekNetto * (1 + Number(ekTaxRate) / 100) + Number.EPSILON) * 100) / 100
+          : null;
+
+      const hasPriceInfo =
+        vkNetto != null || vkBrutto != null || ekNetto != null || ekBrutto != null || kind === 'quote';
+
       return (
         <Box
           sx={{
@@ -480,8 +532,8 @@ class ManifestFormLine extends PureComponent {
             </Typography>
           )}
 
-          {/* VK Netto & VK Brutto: omit end on 2nd line for order */}
-          {!isOrder && (vkNetto != null || vkBrutto != null) && (
+          {/* EK Netto, EK Brutto, VK Netto, VK Brutto */}
+          {!isOrder && hasPriceInfo && (
             <Box
               sx={{
                 display: 'flex',
@@ -491,6 +543,47 @@ class ManifestFormLine extends PureComponent {
                 whiteSpace: 'nowrap',
               }}
             >
+              {/* EK Netto */}
+              <Tooltip
+                title={
+                  topSupplier?.supplierName
+                    ? `Lieferant: ${topSupplier.supplierName}${topSupplier.sku ? ` (Lief.-Art.-Nr.: ${topSupplier.sku})` : ''} (Sort: ${topSupplier.sort ?? 0})`
+                    : 'Kein Lieferant mit EK-Preis hinterlegt'
+                }
+              >
+                <Typography
+                  variant="caption"
+                  fontWeight={600}
+                  sx={{
+                    color: ekNetto != null ? 'text.secondary' : 'text.disabled',
+                    fontSize: '0.72rem',
+                  }}
+                >
+                  EK Netto: {ekNetto != null ? formatPrice(ekNetto) : '—'}
+                </Typography>
+              </Tooltip>
+
+              {/* EK Brutto */}
+              <Tooltip
+                title={
+                  topSupplier?.supplierName
+                    ? `Lieferant: ${topSupplier.supplierName} (inkl. ${ekTaxRate}% MwSt.)`
+                    : 'Kein Lieferant mit EK-Preis hinterlegt'
+                }
+              >
+                <Typography
+                  variant="caption"
+                  fontWeight={600}
+                  sx={{
+                    color: ekBrutto != null ? 'text.secondary' : 'text.disabled',
+                    fontSize: '0.72rem',
+                  }}
+                >
+                  EK Brutto: {ekBrutto != null ? formatPrice(ekBrutto) : '—'}
+                </Typography>
+              </Tooltip>
+
+              {/* VK Netto */}
               {vkNetto != null && (
                 <Typography
                   variant="caption"
@@ -500,6 +593,8 @@ class ManifestFormLine extends PureComponent {
                   VK Netto: {formatPrice(vkNetto)}
                 </Typography>
               )}
+
+              {/* VK Brutto */}
               {vkBrutto != null && (
                 <Typography
                   variant="caption"
diff --git a/src/components/manifest/manifestConfig.js b/src/components/manifest/manifestConfig.js
index 92d326f..6ac648e 100644
--- a/src/components/manifest/manifestConfig.js
+++ b/src/components/manifest/manifestConfig.js
@@ -107,12 +107,13 @@ export function lineFromApi(row) {
   const taxVal = row.taxrate != null ? String(row.taxrate) : row.tax != null ? String(row.tax) : '';
   const netNum = parseNum(netVal);
   const taxNum = parseNum(taxVal);
+  const rebateNum = parseNum(row.rebate) ?? 0;
   let grossVal = '';
   if (row.gross != null && row.gross !== '') {
     grossVal = String(row.gross);
   } else if (netNum != null) {
     const rate = taxNum ?? 0;
-    const g = Math.round((netNum * (1 + rate / 100) + Number.EPSILON) * 100) / 100;
+    const g = Math.round((netNum * (1 + rate / 100) * (1 - rebateNum / 100) + Number.EPSILON) * 100) / 100;
     grossVal = String(g);
   }
   return {
@@ -175,10 +176,10 @@ export function buildLines(lines, { requireAtLeastOne }) {
     const tax = parseNum(rawTax);
     const rawGross = getFirstVal(line.gross);
     const gross = parseNum(rawGross);
-    if (net == null && gross != null && tax != null) {
-      net = netFromGross(gross, tax);
-    }
     const rebate = parseNum(getFirstVal(line.rebate));
+    if (net == null && gross != null && tax != null) {
+      net = netFromGross(gross, tax, rebate ?? 0);
+    }
     const rawPu = getFirstVal(line.pu, line.vpe);
     const pu = parseNum(rawPu);
     const blank = !sku && !name && net == null && gross == null;
diff --git a/src/utils/price.js b/src/utils/price.js
index 66da678..de2b263 100644
--- a/src/utils/price.js
+++ b/src/utils/price.js
@@ -45,12 +45,26 @@ export function parsePriceInput(value) {
 }
 
 /** Convert gross (brutto) → net for PUT /prices. Rounded to 4 decimal places. */
-export function netFromGross(gross, taxRate) {
+export function netFromGross(gross, taxRate, rebate = 0) {
   if (gross == null || taxRate == null) return null;
   if (!Number.isFinite(gross) || !Number.isFinite(taxRate) || taxRate < 0) return null;
-  const factor = 1 + taxRate / 100;
-  if (factor <= 0) return null;
-  return Math.round((gross / factor) * 10000) / 10000;
+  const taxFactor = 1 + taxRate / 100;
+  if (taxFactor <= 0) return null;
+  const r = Number.isFinite(rebate) ? rebate : 0;
+  const rebateFactor = 1 - r / 100;
+  if (rebateFactor <= 0) return 0;
+  return Math.round((gross / (taxFactor * rebateFactor)) * 10000) / 10000;
+}
+
+/** Convert net → gross taking taxRate and optional rebate into account. Rounded to 2 decimal places. */
+export function grossFromNet(net, taxRate = 0, rebate = 0) {
+  if (net == null) return null;
+  const netNum = Number(net);
+  if (!Number.isFinite(netNum)) return null;
+  const taxNum = Number(taxRate) || 0;
+  const rebateNum = Number(rebate) || 0;
+  const factor = (1 + taxNum / 100) * (1 - rebateNum / 100);
+  return Math.round((netNum * factor + Number.EPSILON) * 100) / 100;
 }
 
 /**