This example displays daily COVID-19 cases for five Scandinavian countries throughout October 2020 on a logarithmic scale. The black-background chart uses colored lines for Sweden, Denmark, Norway, Finland, and Iceland. The visualization loads CSV data via `d3.csv`, builds scales with `scaleLinear` and `scaleLog`, and renders paths with the `d3.line` generator. SVG elements handle axes, labels, a title, and a legend, demonstrating D3 v7's data-joining and axis APIs.