Each nucleotide in the sequence is rendered as a column of four black-bordered squares, one per DNA base, whose fill opacity encodes its relative frequency at that position. The visualization highlights compositional patterns across the sequence, with darker squares indicating more abundant bases. Built with React components and D3’s `csv` loader, the data comes from a remote `nucleon.csv` file. The SVG rendering is handled through custom `Nucleon`, `Nucleotide`, and `Square` components, each drawing a fixed-size `rect` with an opacity value derived from the base’s proportion.