Shapes with SVG and CSS
This example draws a smiley face using SVG shapes to demonstrate D3's arc generator and selection methods alongside CSS styling. A yellow circle forms the head, with black circles for eyes and rectangles for eyebrows, while an arc creates the mouth. The right eyebrow animates via chained D3 transitions, moving down then back up over four seconds. The code uses d3.arc for the mouth path and d3.select with attribute setters for shape properties.