diff --git a/modules/shared/auth/ui/home.php b/modules/shared/auth/ui/home.php
index 75f6fb5..f4325e1 100644
--- a/modules/shared/auth/ui/home.php
+++ b/modules/shared/auth/ui/home.php
@@ -87,6 +87,20 @@ function auth_market_status_signal_class(string $status): string
     ][$status] ?? '';
 }
 
+function auth_large_table_default_width(int $columnCount): string
+{
+    return rtrim(rtrim(number_format(100 / max(1, $columnCount), 4, '.', ''), '0'), '.') . '%';
+}
+
+function auth_large_table_resize_handle(string $label, int $columnIndex, int $columnCount): string
+{
+    if ($columnIndex >= $columnCount - 1) {
+        return '';
+    }
+
+    return '<span class="sg-large-table__resize-handle" role="separator" tabindex="0" aria-orientation="vertical" aria-label="Breite von ' . auth_escape_html($label) . ' anpassen" data-large-table-resize-handle="' . $columnIndex . '"></span>';
+}
+
 function auth_render_markets_large_table(array $marketTable): string
 {
     $rows = $marketTable['rows'] ?? $marketTable;
@@ -107,14 +121,14 @@ function auth_render_markets_large_table(array $marketTable): string
     $html = [];
     $html[] = '<section class="sg-card-list-page" aria-label="Marktdurchführungen">';
     $html[] = '<article class="sg-card" data-component="basic-card"><div class="sg-card-segment sg-card-segment--body sg-card-segment--gray" data-component-part="card-body"><div class="sg-component-row sg-basic-card__actions"><button class="sg-interaction-element sg-button sg-button--active" type="button" aria-haspopup="dialog" aria-expanded="false" data-component="button" data-component-state="active" data-market-occurrence-create>Neue Marktdurchführung</button></div></div></article>';
-    $html[] = '<article class="sg-card sg-large-table sg-large-table--markets" data-component="large-table" data-markets-large-table="true" data-markets-search="' . auth_escape_html($search) . '" data-markets-sort-column="' . auth_escape_html($sortColumn) . '" data-markets-sort-direction="' . auth_escape_html($sortDirection) . '" data-markets-limit="' . $limit . '" data-markets-page-size="' . $pageSize . '" role="table" aria-label="Marktdurchführungen">';
+    $html[] = '<article class="sg-card sg-large-table sg-large-table--markets" data-component="large-table" data-column-resize="true" data-column-resize-key="market-occurrences" data-column-min-width="8rem" data-markets-large-table="true" data-markets-search="' . auth_escape_html($search) . '" data-markets-sort-column="' . auth_escape_html($sortColumn) . '" data-markets-sort-direction="' . auth_escape_html($sortDirection) . '" data-markets-limit="' . $limit . '" data-markets-page-size="' . $pageSize . '" role="table" aria-label="Marktdurchführungen">';
     $html[] = '<div class="sg-card-segment sg-card-segment--header sg-card-segment--darkblue sg-large-table__title-segment" data-component-part="large-table-header">';
     $html[] = '<div class="sg-strong">Marktdurchführungen</div>';
     $html[] = '<span class="sg-search-field-row" data-component="search-field">';
     $html[] = '<span class="sg-input-single-line-wrap" data-has-value="' . ($search !== '' ? 'true' : 'false') . '" data-component="single-line-input" data-component-state="' . ($search !== '' ? 'active' : 'inactive-selectable') . '">';
     $html[] = '<input class="sg-interaction-element sg-input-single-line sg-search-field-input sg-input-single-line--inactive-selectable sg-form-inactive-selectable" type="text" placeholder="Suche" aria-label="Marktdurchführungen durchsuchen" value="' . auth_escape_html($search) . '" data-markets-search-input>';
     $html[] = '<button class="sg-input-clear-button" type="button" aria-label="Eingabe löschen" data-markets-search-clear>×</button>';
-    $html[] = '</span></span></div>';
+    $html[] = '</span></span></div><button class="sg-large-table__reset-widths" type="button" data-large-table-reset-widths>Standardbreiten</button>';
     $html[] = '<div class="sg-card-segment sg-card-segment--body sg-card-segment--white sg-large-table__row sg-large-table__row--header" role="row" data-component-part="large-table-header-row">';
     $headerIndex = 0;
     foreach ($sortColumns as $column => $label) {
@@ -123,10 +137,10 @@ function auth_render_markets_large_table(array $marketTable): string
         $iconDirection = $isActive ? strtolower($sortDirection) : 'ascending';
         $targetDirection = $isActive ? ($sortDirection === 'ASC' ? 'DESC' : 'ASC') : ($column === 'earliest_date' ? 'ASC' : 'ASC');
         $ariaLabel = $isActive ? $label . ' ' . ($sortDirection === 'ASC' ? 'aufsteigend sortiert' : 'absteigend sortiert') : $label . ' sortieren';
-        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader" aria-sort="' . $headerDirection . '" data-sort-key="' . $headerIndex . '"><button class="sg-large-table__sort-button" type="button" aria-label="' . auth_escape_html($ariaLabel) . '" data-markets-sort-button="true" data-markets-sort-column="' . auth_escape_html($column) . '" data-markets-sort-direction="' . auth_escape_html($targetDirection) . '"><span class="sg-large-table__sort-label">' . auth_escape_html($label) . '</span><span class="sg-large-table__sort-icon" aria-hidden="true" data-direction="' . auth_escape_html($iconDirection) . '"></span></button></div>';
+        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader" aria-sort="' . $headerDirection . '" data-sort-key="' . $headerIndex . '" data-default-width="' . auth_large_table_default_width(6) . '"><button class="sg-large-table__sort-button" type="button" aria-label="' . auth_escape_html($ariaLabel) . '" data-markets-sort-button="true" data-markets-sort-column="' . auth_escape_html($column) . '" data-markets-sort-direction="' . auth_escape_html($targetDirection) . '"><span class="sg-large-table__sort-label">' . auth_escape_html($label) . '</span><span class="sg-large-table__sort-icon" aria-hidden="true" data-direction="' . auth_escape_html($iconDirection) . '"></span></button>' . auth_large_table_resize_handle($label, $headerIndex, 6) . '</div>';
         $headerIndex++;
     }
-    $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader">Verkaufte Produkte</div>';
+    $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader" data-default-width="' . auth_large_table_default_width(6) . '"><span class="sg-large-table__sort-label">Verkaufte Produkte</span></div>';
     $html[] = '</div>';
 
     foreach ($rows as $index => $row) {
@@ -183,11 +197,12 @@ function auth_render_market_definitions_content(array $marketTable): string
     $html = [];
     $html[] = '<div data-market-definitions-content="true" data-market-definitions-csrf-token="' . auth_escape_html(auth_csrf_token()) . '"><section class="sg-card-list-page" aria-label="Märkte">';
     $html[] = '<article class="sg-card" data-component="basic-card"><div class="sg-card-segment sg-card-segment--body sg-card-segment--gray" data-component-part="card-body"><div class="sg-component-row sg-basic-card__actions"><button class="sg-interaction-element sg-button sg-button--active" type="button" aria-haspopup="dialog" aria-expanded="false" data-component="button" data-market-definition-create>Neuer Markt</button></div></div></article>';
-    $html[] = '<article class="sg-card sg-large-table sg-large-table--markets" data-component="large-table" data-market-definitions-table="true" role="table" aria-label="Märkte">';
-    $html[] = '<div class="sg-card-segment sg-card-segment--header sg-card-segment--darkblue sg-large-table__title-segment" data-component-part="large-table-header"><div class="sg-strong">Märkte</div></div>';
+    $html[] = '<article class="sg-card sg-large-table sg-large-table--markets" data-component="large-table" data-column-resize="true" data-column-resize-key="market-definitions" data-column-min-width="8rem" data-market-definitions-table="true" role="table" aria-label="Märkte">';
+    $html[] = '<div class="sg-card-segment sg-card-segment--header sg-card-segment--darkblue sg-large-table__title-segment" data-component-part="large-table-header"><div class="sg-strong">Märkte</div><button class="sg-large-table__reset-widths" type="button" data-large-table-reset-widths>Standardbreiten</button></div>';
     $html[] = '<div class="sg-card-segment sg-card-segment--body sg-card-segment--white sg-large-table__row sg-large-table__row--header" role="row" data-component-part="large-table-header-row">';
-    foreach (['Markt', 'Kategorie', 'Veranstalter', 'Website', 'Durchführungen', 'Status'] as $label) {
-        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader">' . auth_escape_html($label) . '</div>';
+    $definitionColumns = ['Markt', 'Kategorie', 'Veranstalter', 'Website', 'Durchführungen', 'Status'];
+    foreach ($definitionColumns as $index => $label) {
+        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader" data-default-width="' . auth_large_table_default_width(count($definitionColumns)) . '"><span class="sg-large-table__sort-label">' . auth_escape_html($label) . '</span>' . auth_large_table_resize_handle($label, $index, count($definitionColumns)) . '</div>';
     }
     $html[] = '</div>';
     foreach ($rows as $index => $row) {
@@ -244,7 +259,7 @@ function auth_render_bestellungen_large_table(array $bestellungenTable): string
 
     $html = [];
     $html[] = '<section class="sg-card-list-page" aria-label="Bestellungen">';
-    $html[] = '<article class="sg-card sg-large-table sg-large-table--bestellungen" style="margin-top: var(--spacing-large);" data-component="large-table" data-bestellungen-large-table="true" data-bestellungen-search="' . auth_escape_html($search) . '" data-bestellungen-sort-column="' . auth_escape_html($sortColumn) . '" data-bestellungen-sort-direction="' . auth_escape_html($sortDirection) . '" data-bestellungen-limit="' . $limit . '" data-bestellungen-page-size="' . $pageSize . '" role="table" aria-label="Bestellungen">';
+    $html[] = '<article class="sg-card sg-large-table sg-large-table--bestellungen" style="margin-top: var(--spacing-large);" data-component="large-table" data-column-resize="true" data-column-resize-key="orders" data-column-min-width="8rem" data-bestellungen-large-table="true" data-bestellungen-search="' . auth_escape_html($search) . '" data-bestellungen-sort-column="' . auth_escape_html($sortColumn) . '" data-bestellungen-sort-direction="' . auth_escape_html($sortDirection) . '" data-bestellungen-limit="' . $limit . '" data-bestellungen-page-size="' . $pageSize . '" role="table" aria-label="Bestellungen">';
     $html[] = '<div class="sg-card-segment sg-card-segment--header sg-card-segment--darkblue sg-large-table__title-segment" data-component-part="large-table-header">';
     $html[] = '<div class="sg-strong">Bestellungen</div>';
     $html[] = '<span class="sg-search-field-row" data-component="search-field">';
@@ -253,6 +268,7 @@ function auth_render_bestellungen_large_table(array $bestellungenTable): string
     $html[] = '<button class="sg-input-clear-button" type="button" aria-label="Eingabe löschen" data-bestellungen-search-clear>×</button>';
     $html[] = '</span>';
     $html[] = '</span>';
+    $html[] = '<button class="sg-large-table__reset-widths" type="button" data-large-table-reset-widths>Standardbreiten</button>';
     $html[] = '</div>';
     $html[] = '<div class="sg-card-segment sg-card-segment--body sg-card-segment--white sg-large-table__row sg-large-table__row--header" role="row" data-component-part="large-table-header-row">';
 
@@ -269,11 +285,11 @@ function auth_render_bestellungen_large_table(array $bestellungenTable): string
             : ($column === 'order_date' ? 'DESC' : 'ASC');
 
         $amountHeaderClass = $column === 'total_amount' ? ' sg-large-table__cell--amount' : '';
-        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header' . $amountHeaderClass . '" role="columnheader" aria-sort="' . $headerDirection . '" data-sort-key="' . $headerIndex . '">';
+        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header' . $amountHeaderClass . '" role="columnheader" aria-sort="' . $headerDirection . '" data-sort-key="' . $headerIndex . '" data-default-width="' . auth_large_table_default_width(4) . '">';
         $html[] = '<button class="sg-large-table__sort-button" type="button" aria-label="' . auth_escape_html($ariaLabel) . '" data-bestellungen-sort-button="true" data-bestellungen-sort-column="' . auth_escape_html($column) . '" data-bestellungen-sort-direction="' . auth_escape_html($targetDirection) . '">';
         $html[] = '<span class="sg-large-table__sort-label">' . auth_escape_html($label) . '</span>';
         $html[] = '<span class="sg-large-table__sort-icon" aria-hidden="true" data-direction="' . auth_escape_html($iconDirection) . '"></span>';
-        $html[] = '</button>';
+        $html[] = '</button>' . auth_large_table_resize_handle($label, $headerIndex, 4);
         $html[] = '</div>';
         $headerIndex++;
     }
@@ -388,11 +404,11 @@ function auth_render_lager_table(string $title, array $rows, array $columns, str
         return ['text' => $text, 'warning' => $warning, 'mhdWarning' => $mhdWarning];
     };
     $html = [];
-    $html[] = '<article class="sg-card sg-large-table sg-large-table--lager" data-component="large-table" data-lager-table="true" data-lager-table-key="' . auth_escape_html($tableKey) . '" role="table" aria-label="' . auth_escape_html($title) . '">';
-    $html[] = '<div class="sg-card-segment sg-card-segment--header sg-card-segment--darkblue sg-large-table__title-segment" data-component-part="large-table-header"><div class="sg-strong">' . auth_escape_html($title) . '</div></div>';
+    $html[] = '<article class="sg-card sg-large-table sg-large-table--lager" data-component="large-table" data-column-resize="true" data-column-resize-key="lager-' . auth_escape_html($tableKey) . '" data-column-min-width="8rem" data-lager-table="true" data-lager-table-key="' . auth_escape_html($tableKey) . '" role="table" aria-label="' . auth_escape_html($title) . '">';
+    $html[] = '<div class="sg-card-segment sg-card-segment--header sg-card-segment--darkblue sg-large-table__title-segment" data-component-part="large-table-header"><div class="sg-strong">' . auth_escape_html($title) . '</div><button class="sg-large-table__reset-widths" type="button" data-large-table-reset-widths>Standardbreiten</button></div>';
     $html[] = '<div class="sg-card-segment sg-card-segment--body sg-card-segment--white sg-large-table__row sg-large-table__row--header" role="row" data-component-part="large-table-header-row">';
-    foreach ($columns as $label) {
-        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader"><span class="sg-large-table__sort-label">' . auth_escape_html($label) . '</span></div>';
+    foreach ($columns as $index => $label) {
+        $html[] = '<div class="sg-large-table__cell sg-large-table__cell--header" role="columnheader" data-default-width="' . auth_large_table_default_width(count($columns)) . '"><span class="sg-large-table__sort-label">' . auth_escape_html($label) . '</span>' . auth_large_table_resize_handle($label, $index, count($columns)) . '</div>';
     }
     $html[] = '</div>';
 
@@ -932,10 +948,13 @@ function render_auth_home_page(array $user, array $otcProducts = [], array $otcM
     echo '<script src="/scripts/help-icon-overlays.js"></script>';
     echo '<script src="/scripts/shared-editable-action-card.js?v=20260920-2"></script>';
     echo '<script src="/scripts/shared-mobile-detail.js?v=20260925-1"></script>';
+    echo '<script src="/scripts/large-table-column-resize.js?v=' . filemtime(__DIR__ . '/../../../../public/scripts/large-table-column-resize.js') . '"></script>';
     echo '<script>';
     echo 'const portalModuleNavigation = ' . $moduleNavigation . ';';
     echo 'const portalModuleContentCards = ' . $moduleContentCards . ';';
     echo 'const portalModuleHeadings = ' . $moduleHeadings . ';';
+    echo "const portalContentBody = document.querySelector('[data-left-navigation-content-body]');";
+    echo "if (portalContentBody && window.sgInitLargeTableColumnResize) { const portalLargeTableResizeObserver = new MutationObserver(() => window.sgInitLargeTableColumnResize({ root: portalContentBody })); portalLargeTableResizeObserver.observe(portalContentBody, { childList: true, subtree: true }); window.sgInitLargeTableColumnResize({ root: portalContentBody }); }";
     echo "const renderMainHeading = (moduleName) => {";
     echo "  const heading = document.querySelector('[data-main-heading]');";
     echo "  if (heading && portalModuleHeadings[moduleName]) { heading.textContent = portalModuleHeadings[moduleName]; }";
@@ -1179,7 +1198,7 @@ function render_auth_home_page(array $user, array $otcProducts = [], array $otcM
     echo "  const replaceFragment = (html) => { const doc = new DOMParser().parseFromString(html, 'text/html'); const fragment = doc.querySelector('[data-markets-content]'); if (!fragment) { return false; } contentRoot.innerHTML = fragment.outerHTML; return Boolean(getTable()); };";
     echo "  const loadFragment = async (params) => { if (searchTimer) { window.clearTimeout(searchTimer); searchTimer = null; } const input = getSearchInput(); const wasFocused = input ? document.activeElement === input : false; const response = await fetch(buildUrl({ ...params, market_fragment: '1' }).toString(), { credentials: 'same-origin', headers: { 'X-Requested-With': 'XMLHttpRequest' } }); if (!response.ok) { return; } const replaced = replaceFragment(await response.text()); if (!replaced) { return; } window.history.replaceState({}, '', buildUrl(params)); bindTable(); if (wasFocused) { const nextInput = getSearchInput(); nextInput?.focus({ preventScroll: true }); if (nextInput) { nextInput.setSelectionRange(nextInput.value.length, nextInput.value.length); } } };";
     echo "  const syncSearchState = () => { const input = getSearchInput(); const wrap = input?.closest('[data-component=\'single-line-input\']'); if (!input || !wrap) { return; } const hasValue = input.value.trim() !== ''; wrap.setAttribute('data-has-value', String(hasValue)); wrap.dataset.componentState = hasValue ? 'active' : 'inactive-selectable'; };";
-    echo "  const bindTable = () => { const table = getTable(); if (!table) { return; } const input = getSearchInput(); const clearButton = table.querySelector('[data-markets-search-clear]'); if (input && input.dataset.marketsBound !== 'true') { input.dataset.marketsBound = 'true'; input.addEventListener('input', () => { syncSearchState(); if (searchTimer) { window.clearTimeout(searchTimer); } searchTimer = window.setTimeout(() => { void loadFragment({ market_search: getSearchValue(), market_sort: getSortColumn(), market_dir: getSortDirection(), market_limit: getPageSize() }); }, 500); }); } if (clearButton && clearButton.dataset.marketsBound !== 'true') { clearButton.dataset.marketsBound = 'true'; clearButton.addEventListener('click', () => { const currentInput = getSearchInput(); if (currentInput) { currentInput.value = ''; } syncSearchState(); void loadFragment({ market_search: '', market_sort: getSortColumn(), market_dir: getSortDirection(), market_limit: getPageSize() }); }); } syncSearchState(); };";
+    echo "  const bindTable = () => { const table = getTable(); if (!table) { return; } if (window.sgInitLargeTableColumnResize) { window.sgInitLargeTableColumnResize({ root: contentRoot }); } const input = getSearchInput(); const clearButton = table.querySelector('[data-markets-search-clear]'); if (input && input.dataset.marketsBound !== 'true') { input.dataset.marketsBound = 'true'; input.addEventListener('input', () => { syncSearchState(); if (searchTimer) { window.clearTimeout(searchTimer); } searchTimer = window.setTimeout(() => { void loadFragment({ market_search: getSearchValue(), market_sort: getSortColumn(), market_dir: getSortDirection(), market_limit: getPageSize() }); }, 500); }); } if (clearButton && clearButton.dataset.marketsBound !== 'true') { clearButton.dataset.marketsBound = 'true'; clearButton.addEventListener('click', () => { const currentInput = getSearchInput(); if (currentInput) { currentInput.value = ''; } syncSearchState(); void loadFragment({ market_search: '', market_sort: getSortColumn(), market_dir: getSortDirection(), market_limit: getPageSize() }); }); } syncSearchState(); };";
     echo "  let marketMobileDetailHost = null; let marketOpeningMobileDetail = false; let marketDetailOpen = false;";
     echo "  const marketMobileDetail = window.SharedMobileDetail?.create({ contentRoot, bodyClass: 'sg-market-mobile-detail-open', hostClass: 'sg-market-mobile-detail-host', hostDataAttribute: 'data-market-mobile-detail-host', drawerDataAttribute: 'data-market-mobile-drawer', backMarkup: '<div class=\"sg-navigation-card-layout sg-mobile-detail-back-card\"><div class=\"sg-navigation-card-block\"><article class=\"sg-card\" data-component=\"card\" data-pattern=\"navigation-card\"><div class=\"sg-card-segment sg-card-segment--body\"><div class=\"sg-navigation-card-center\"><button class=\"sg-interaction-element sg-hyperlink\" type=\"button\" data-market-detail-back>zurück</button></div></div></article></div></div>', historyKey: 'marketView' });";
     echo "  const getMarketDrawer = () => document.querySelector('[data-market-mobile-drawer]') || contentRoot.querySelector('[data-market-drawer]');";
diff --git a/public/assets/styles.portal.css b/public/assets/styles.portal.css
index 44f28d0..0264cf7 100644
--- a/public/assets/styles.portal.css
+++ b/public/assets/styles.portal.css
@@ -303,7 +303,7 @@ body.sg-lager-mobile-detail-open > :not([data-lager-mobile-detail-host]) {
   }
 
   .sg-large-table--bestellungen .sg-large-table__row {
-    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1.35fr) fit-content(12.5ch);
+    grid-template-columns: var(--large-table-grid-template-columns, minmax(0, 1.15fr) minmax(0, 1.35fr) fit-content(12.5ch));
   }
 
   .sg-large-table--bestellungen .sg-large-table__row > :nth-child(2) {
@@ -316,7 +316,7 @@ body.sg-lager-mobile-detail-open > :not([data-lager-mobile-detail-host]) {
 }
 
 .sg-large-table--bestellungen .sg-large-table__row {
-  grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr) minmax(0, 1.35fr) fit-content(12.5ch);
+  grid-template-columns: var(--large-table-grid-template-columns, minmax(0, 1.2fr) minmax(0, 1fr) minmax(0, 1.35fr) fit-content(12.5ch));
 }
 
 .sg-large-table--bestellungen .sg-large-table__cell--amount {
@@ -339,15 +339,15 @@ body.sg-lager-mobile-detail-open > :not([data-lager-mobile-detail-host]) {
 }
 
 .sg-large-table--lager .sg-large-table__row {
-  grid-template-columns: repeat(2, minmax(0, 1fr));
+  grid-template-columns: var(--large-table-grid-template-columns, repeat(2, minmax(0, 1fr)));
 }
 
 .sg-large-table--markets .sg-large-table__row {
-  grid-template-columns: repeat(6, minmax(0, 1fr));
+  grid-template-columns: var(--large-table-grid-template-columns, repeat(6, minmax(0, 1fr)));
 }
 
 .sg-large-table--lager[data-lager-table-key="products"] .sg-large-table__row {
-  grid-template-columns: 30% repeat(4, minmax(0, 1fr));
+  grid-template-columns: var(--large-table-grid-template-columns, 30% repeat(4, minmax(0, 1fr)));
 }
 
 .sg-large-table--lager[data-lager-table-key="products"] .sg-large-table__cell:last-child {