"thisIsOk" }}';          // e.g. "Operational"
						}

						// Full tooltip: dateStr + localized severity
						bar.setAttribute('data-label', ds.dateStr + ' — ' + labelText);

						// Assign color by worstSeverity
						if (ds.worstSeverity === 'down') {
							bar.style.backgroundColor = themeDownColor;
						} else if (ds.worstSeverity === 'disrupted') {
							bar.style.backgroundColor = themeDisruptedColor;
						} else {
							bar.style.backgroundColor = themeOkColor;
						}

						histogramDiv