Center PDF title and improve code/list formatting

- Centered note title in PDF exports for better visual balance
- Increased inline code font size from 0.9em to 1.1em for better readability
- Removed paragraph margins inside list items to fix spacing issues

src/index.css

@@ -116,7 +116,7 @@ code {
   padding: 0.125rem 0.25rem;
   border-radius: 0.25rem;
   font-family: 'Courier New', monospace;
-  font-size: 0.9em;
+  font-size: 1.1em;
   color: #1f2937;
 }
 
@@ -169,6 +169,10 @@ code {
   color: #111827;
 }
 
+.ProseMirror li p {
+  margin: 0;
+}
+
 .dark .ProseMirror li {
   color: #f3f4f6;
 }