le.error('Fetch error:', error);
                if (error.message.includes('HTTP 403')) throw new Error('API rate limit exceeded.');
                if (error.message.includes('HTTP 404')) throw new Error('Repository or README not found.');
                if (!navigator.onLine) throw new Error('No internet connection detected.');
                throw new Error(`Failed to fetch content: ${error.message}`);
            }
        }

        // --- Content Rendering ---
        function renderMarkdown(conten