LineChart changelog

Retain a 4 CSS px floor for the shared HoverPanel dot-to-name and name-to-value gaps in LTR and RTL. Preserve the default 4px / 8px gaps, larger tokens, chart geometry, and center annotations.

Localized the built-in root accessible name and data-cell group name through the shared locale protocol. Explicit aria-label values retain priority; business names and numeric formatting remain unchanged.

2026-09-21: Unified the usage guide, source property table, and Site / AI reading entry points. Documentation only; component behavior is unchanged.

Multi-series appearance now computes one linear timeline per frame. Raw HoverPanel pointer events no longer read layout synchronously; coordinate conversion is combined by render frame. Public API, paths, markers, duration, visuals, and interaction semantics are unchanged.

Added showBaseLayer=false to enable same-color outlines at their final size on demand. Real graphics and entrance motion retain their behavior.
adaptiveContrast is enabled by default; explicit disabling and child-chart overrides remain available.

adaptiveContrast now uses shared adaptive black-and-white contrast. Toggle defaults, colored foregrounds, hit testing, and node-state semantics remain; the chart-private experimental implementation was removed.

HoverPanel now defaults to pointer positioning and follows the mouse. Area hover still defaults to cell; explicit placement / hoverMode settings take precedence.

Top value labels no longer enlarge the safety area. They remain 4px above nodes and may overflow the plot area’s top edge; default color is Black/100%.

Automatic domain upper bound now uses the actual maximum data value, so the highest nice tick no longer exceeds it. Only content determines the top safety area.

The top is now a content-aware safety area computed from the Y axis, hover label, line width, and marker radius. Automatic nice-domain selection was tightened as well.

Removed extra top and bottom whitespace from the Cartesian plot area; only the 24px needed by X-axis labels remains at the bottom.

Y-axis width now adapts to the actual rendered width of the widest visible label, with a fixed 12px gap to the plot area.

Markers now have two circular layers: an 8×8 Black/100% circle underneath and a 4×4 White/100% circle above, without a node shadow.
Marker hover / focus gained inverted colors and a 0.5px Black/100% round-capped vertical line behind the node.

Added shared Chart colorMode: sequence, monochromeFade, and monochrome.
Added primary color plus separate monochromeColor / mutedMonochromeColor entries. All three color modes support per-series custom colors through series[i].color and colors[i].

Removed internal example data defaults; series and xLabels now default to [].
LC-01 and LC-09 examples now pass monthly data explicitly. LC-09 became a full coordinate chart showing rounded line corners in a realistic chart.
The X axis supports cell and edge point-position models. In edge, the first and last data points and guides align with both plot-area edges, while end label boxes may shift inward to remain fully visible. Long labels thin only their text; all data points and interactions keep their original indices.
Retained only rounded-corner polylines and removed the curve API. cornerRadius=0 produces straight lines.
Y-axis ticks are generated as nice ticks from data. The default color sequence returned to ChartSpec, and default line width changed to 1px.
Consolidated Area API to area: boolean, using a gradient from the current line color to 0% opacity. Default marker size changed to 12px; individual points cannot override color.

Added shared Chart entrance-motion API, scrolling timeline, controlled progress, and replay() / resetAppearance() / reverseAppearance() methods.
Added a complete base layer and transparent marker hit circles, bringing layers and interactions closer to ChartSpec.
Added cornerRadius for mostly straight segments with local rounded turns. It later became the sole line-shape API.

Initial release with multiple series, solid / dashed lines, X and Y axes, horizontal grid, and customizable markers.
Supports series[].area, combining Area fill with solid or dashed lines.