Test-Barchart
A bar chart displays the ten most populous countries, with population values plotted horizontally and country names along the vertical axis. The chart uses `d3.csv` to load population data from `data.csv`, converting the strings to numbers before rendering. `d3.scaleLinear` maps the population domain to pixel width, while `d3.scaleBand` positions the categorical country labels. SVG `rect` elements are drawn with heights set by the band’s `bandwidth()`, and axis ticks are generated via `d3.axisLeft` and `d3.axisBottom`, with custom tick formatting using `d3.format`. The background is styled yellow via inline SVG styling.