Interface AreaStyle

A resolved area style: an outline stroke plus a graded fill. color/width stroke the value line on top; fill is the gradient base colour, opaque (scaled by fillOpacity, 0–1) at the line and grading to transparent at the baseline. fill must be a CSS hex (#rgb / #rrggbb) so the transparent stop can be derived; other formats fall back to a flat fill.

interface AreaStyle {
    color: string;
    fill: string;
    fillOpacity: number;
    width: number;
}