How can we create the tooltip in that way? If your guess was: before or: after pseudo-elements, you are correct. Those are tooltips! Even thought it can seem intimidating to start creating your first ...

data-tooltip: classTooltip: Tooltip class prefix: tooltip-component: style: Custom CSS styles, this will replace the default one '' styleAdditional: Additional CSS styles '' privateClasses: Make all ...

Another way to add tooltips to your d3.js line chart is to use the d3-tip library, which allows you to create and style tooltips with HTML and CSS.