       section.className = 'line-controls';

        // Controls column
        const controlsColumn = document.createElement('div');
        controlsColumn.className = 'controls-column';

        // Active checkbox with instrument name
        const activeLabel = document.createElement('label');
        const activeCheckbox = document.createElement('input');
        activeCheckbox.type = 'checkbox';
        activeCheckbox.id = `${lineType.id}-active`;
        activeCheckbox.checked = lineType.checked;
    