diff --git a/x-pack/plugins/observability/public/pages/alerts/index.tsx b/x-pack/plugins/observability/public/pages/alerts/index.tsx
index fb23856dcd5a3..51d5f52bfea87 100644
--- a/x-pack/plugins/observability/public/pages/alerts/index.tsx
+++ b/x-pack/plugins/observability/public/pages/alerts/index.tsx
@@ -27,6 +27,7 @@ import { AlertsTableTGrid } from './alerts_table_t_grid';
 import { StatusFilter } from './status_filter';
 import { useFetcher } from '../../hooks/use_fetcher';
 import { callObservabilityApi } from '../../services/call_observability_api';
+import './styles.scss';
 
 export interface TopAlert {
   fields: ParsedTechnicalFields;
diff --git a/x-pack/plugins/observability/public/pages/alerts/styles.scss b/x-pack/plugins/observability/public/pages/alerts/styles.scss
new file mode 100644
index 0000000000000..cee2ea31a0ea8
--- /dev/null
+++ b/x-pack/plugins/observability/public/pages/alerts/styles.scss
@@ -0,0 +1,12 @@
+$fullscreenFlyoutTop: 72px;
+.kbnBody.euiBody--headerIsFixed.euiDataGrid__restrictBody {
+  .euiOverlayMask--belowHeader {
+    top: $fullscreenFlyoutTop;
+  }
+
+  .euiFlyout,
+  .euiCollapsibleNav {
+    top: $fullscreenFlyoutTop;
+    height: calc(100% - #{$fullscreenFlyoutTop});
+  }
+}