.appendChild(bar);
					}
				})
				.catch(err => {
					// Handle different types of errors appropriately
					if (err.message && err.message.startsWith('HTTP 404')) {
						// This shouldn't happen since we handle 404s above, but just in case
						console.warn('Histogram: 404 for', systemName, '- treating as continuous uptime');
						histogramDiv.textContent = ''; // Clear "Loading..."
						
						// Build histogram with all OK status (continuous uptime)
						var now = new Date();
						for (var i = 