simple scatterplot
This example shows a simple scatterplot of seven data points, each defined by x and y coordinates on a fixed 960-by-500 SVG canvas. The visualization uses D3 v4 to create the SVG container and relies on the `d3.select` and `attr` methods to set its dimensions. The data is hardcoded as an array of JavaScript objects, and while the code preps the SVG, it does not yet plot any circles or axes, leaving the points unrendered. The body is styled with zero margins to make the chart full-width.