This visualization shows the proportion of smartphone app usage across six age groups, with each horizontal bar segmented into five categories: Social Media, Games, Productivity, Streaming, and Others. A stacked bar chart uses a diverging color palette to distinguish app types, and a legend identifies each category. The chart is rendered as SVG using D3 v7, employing `d3.stack()` for data transformation, `d3.scaleBand()` for the categorical y-axis, and `d3.scaleLinear()` for the percentage x-axis. Data is loaded from a local CSV file (`phones.csv`).