diff --git a/frontend/src/components/RuntimePresentation.tsx b/frontend/src/components/RuntimePresentation.tsx
index 9bfe60a..d1ae29f 100644
--- a/frontend/src/components/RuntimePresentation.tsx
+++ b/frontend/src/components/RuntimePresentation.tsx
@@ -460,16 +460,20 @@ export default function RuntimePresentation({
       element.type === 'navigation_prev'
     ) {
       if (element.iconUrl) {
+        // Use img tag with flexible sizing - auto for dimensions not provided
+        const imgStyle: React.CSSProperties = {
+          width: element.width || 'auto',
+          height: element.height || 'auto',
+          objectFit: 'contain',
+        };
+        // eslint-disable-next-line @next/next/no-img-element
         return (
-          <div className='relative w-full h-full min-w-[40px] min-h-[40px]'>
-            <Image
-              src={resolveAssetPlaybackUrl(element.iconUrl)}
-              alt='Navigation'
-              fill
-              className='object-contain'
-              unoptimized
-            />
-          </div>
+          <img
+            src={resolveAssetPlaybackUrl(element.iconUrl)}
+            alt='Navigation'
+            style={imgStyle}
+            draggable={false}
+          />
         );
       }
       return (
diff --git a/frontend/src/lib/elementStyles.ts b/frontend/src/lib/elementStyles.ts
index eed57fa..d07b2c4 100644
--- a/frontend/src/lib/elementStyles.ts
+++ b/frontend/src/lib/elementStyles.ts
@@ -70,10 +70,13 @@ export const ELEMENT_STYLE_PROPS = [
 const NUMERIC_PROPS = ['opacity', 'zIndex'] as const;
 
 /**
- * Get trimmed CSS value from unknown input
+ * Get trimmed CSS value from unknown input.
+ * Returns empty string for null/undefined, but preserves '0' for explicit zero values.
  */
 const getTrimmedValue = (value: unknown): string => {
   if (value === null || value === undefined) return '';
+  // Preserve 0 as '0' - explicit zero should be applied
+  if (value === 0) return '0';
   return String(value).trim();
 };
 
diff --git a/frontend/src/pages/constructor.tsx b/frontend/src/pages/constructor.tsx
index 19212e9..5cf5a57 100644
--- a/frontend/src/pages/constructor.tsx
+++ b/frontend/src/pages/constructor.tsx
@@ -32,7 +32,7 @@ import { logger } from '../lib/logger';
 import { resolveAssetPlaybackUrl } from '../lib/assetUrl';
 import { parseJsonObject } from '../lib/parseJson';
 import { waitForPageImages } from '../lib/imagePreDecode';
-import { buildElementStyle } from '../lib/elementStyles';
+import { buildElementStyle, ELEMENT_STYLE_PROPS } from '../lib/elementStyles';
 import type { PreloadPageLink, PreloadElement } from '../types/preload';
 import type {
   CanvasElementType,
@@ -418,6 +418,23 @@ const mergeElementWithDefaults = (
     yPercent: element.yPercent ?? defaults.yPercent ?? 50,
   };
 
+  // For style properties, use defaults if element has empty/null/undefined value
+  // This ensures DB defaults are applied when element has no explicit value
+  const elementRecord = element as unknown as Record<string, unknown>;
+  const defaultsRecord = defaults as unknown as Record<string, unknown>;
+  const mergedRecord = merged as unknown as Record<string, unknown>;
+  ELEMENT_STYLE_PROPS.forEach((prop) => {
+    const elementValue = elementRecord[prop];
+    const defaultValue = defaultsRecord[prop];
+    const elementIsEmpty =
+      elementValue === '' || elementValue === undefined || elementValue === null;
+    const defaultHasValue =
+      defaultValue !== undefined && defaultValue !== null && defaultValue !== '';
+    if (elementIsEmpty && defaultHasValue) {
+      mergedRecord[prop] = defaultValue;
+    }
+  });
+
   merged.xPercent = clamp(Number(merged.xPercent ?? element.xPercent), 0, 100);
   merged.yPercent = clamp(Number(merged.yPercent ?? element.yPercent), 0, 100);
   merged.appearDelaySec = normalizeAppearDelaySec(merged.appearDelaySec);
@@ -2089,17 +2106,20 @@ const ConstructorPage = ({ mode = 'constructor' }: ConstructorPageProps) => {
       const fallbackNavLabel = getNavigationButtonLabel(element.type);
       const navigationLabel = element.navLabel?.trim() || fallbackNavLabel;
       if (element.iconUrl) {
+        // Use img tag with flexible sizing - auto for dimensions not provided
+        const imgStyle: React.CSSProperties = {
+          width: element.width || 'auto',
+          height: element.height || 'auto',
+          objectFit: 'contain',
+        };
+        // eslint-disable-next-line @next/next/no-img-element
         return (
-          <div className='relative min-w-[60px] min-h-[60px] w-full h-full'>
-            <NextImage
-              src={resolveAssetPlaybackUrl(element.iconUrl)}
-              alt='Navigation icon'
-              fill
-              sizes='100vw'
-              className='object-contain'
-              draggable={false}
-            />
-          </div>
+          <img
+            src={resolveAssetPlaybackUrl(element.iconUrl)}
+            alt='Navigation icon'
+            style={imgStyle}
+            draggable={false}
+          />
         );
       }