diff --git a/frontend-modern/src/components/shared/Sparkline.tsx b/frontend-modern/src/components/shared/Sparkline.tsx
index a4531af..3dd7b1d 100644
--- a/frontend-modern/src/components/shared/Sparkline.tsx
+++ b/frontend-modern/src/components/shared/Sparkline.tsx
@@ -255,10 +255,10 @@ export const Sparkline: Component<SparklineProps> = (props) => {
   };
 
   return (
-    <div class="relative inline-block">
+    <div class="relative block w-full">
       <canvas
         ref={canvasRef}
-        class="inline-block cursor-crosshair"
+        class="block cursor-crosshair"
         style={{
           width: `${width()}px`,
           height: `${height()}px`,
diff --git a/frontend-modern/src/stores/metricsHistory.ts b/frontend-modern/src/stores/metricsHistory.ts
index 95afefc..60f17ce 100644
--- a/frontend-modern/src/stores/metricsHistory.ts
+++ b/frontend-modern/src/stores/metricsHistory.ts
@@ -112,10 +112,19 @@ function saveToLocalStorage(): void {
 function loadFromLocalStorage(): void {
   try {
     const stored = localStorage.getItem(STORAGE_KEY);
-    if (!stored) return;
+    if (!stored) {
+      logger.debug('[MetricsHistory] No stored data found');
+      return;
+    }
 
     const payload = JSON.parse(stored);
 
+    if (!payload || typeof payload !== 'object') {
+      logger.warn('[MetricsHistory] Invalid payload format, clearing');
+      localStorage.removeItem(STORAGE_KEY);
+      return;
+    }
+
     // Check version and age
     if (payload.version !== STORAGE_VERSION) {
       logger.warn('[MetricsHistory] Storage version mismatch, clearing');