diff --git a/frontend/src/adapters/gateways/EChartsOptionBuilder/index.ts b/frontend/src/adapters/gateways/EChartsOptionBuilder/index.ts
index de65f20..35b6992 100644
--- a/frontend/src/adapters/gateways/EChartsOptionBuilder/index.ts
+++ b/frontend/src/adapters/gateways/EChartsOptionBuilder/index.ts
@@ -23,8 +23,13 @@ const DEFAULT_STYLE: StyleConfig = {
   animation: { enabled: true, duration: 500, easing: 'ease-out' },
 };
 
-function ensureStyle(style: any): StyleConfig {
+function ensureStyle(style: any): StyleConfig & Record<string, any> {
   if (!style || typeof style !== 'object') return DEFAULT_STYLE;
+  const known = new Set(['title','colors','legend','xAxis','yAxis','dataLabel','background','border','animation']);
+  const custom: Record<string, any> = {};
+  for (const key of Object.keys(style)) {
+    if (!known.has(key)) custom[key] = style[key];
+  }
   return {
     title: { ...DEFAULT_STYLE.title, ...(style.title ?? {}) },
     colors: (Array.isArray(style.colors) && style.colors.length > 0) ? style.colors : DEFAULT_STYLE.colors,
@@ -35,6 +40,7 @@ function ensureStyle(style: any): StyleConfig {
     background: { ...DEFAULT_STYLE.background, ...(style.background ?? {}) },
     border: { ...DEFAULT_STYLE.border, ...(style.border ?? {}) },
     animation: { ...DEFAULT_STYLE.animation, ...(style.animation ?? {}) },
+    ...custom,
   };
 }