This example shows a scatter plot of iris flower measurements, encoding sepal length against petal length and using different symbols to distinguish species via a shape legend. It loads data from a remote CSV file and parses it with `d3.csvParse`. The visualization uses D3 v7 features including `d3.scaleLinear`, `d3.scaleOrdinal`, `d3.symbol`, and `d3.axisLeft`/`d3.axisBottom` to render axes and marks, with a custom legend built from modular ES6 functions.