~anthropic/claude-sonnet-latest → B (70:30)

Side B makes a substantive engineering improvement: it removes unnecessary Rc<RefCell<>> indirection in favor of direct HashMap ownership, adds Send+Sync bounds, and caches the graph in a OnceLock instead of rebuilding it on every parse call, improving both performance and correctness. Side A is purely additive CSS styling with no logic changes, useful but lower-impact and more superficial than B's architectural fix to the parser's core data structures.