## Summary
Implements `area-basic` for **matplotlib** library.

**Parent Issue:** #201
**Sub-Issue:** #209
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/matplotlib/fill_between/area-basic/default.py`

## Details
- Uses `ax.fill_between()` for the filled area with semi-transparent
Python Blue color (#306998)
- Includes solid line on top for better edge visibility
- Monthly sales data from the spec with proper categorical x-axis labels
- Y-axis starts at 0 for proper area representation
- Follows KISS style: simple sequential script without functions
- Font sizes and styling per default-style-guide.md

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **pygal** library.

**Parent Issue:** #201
**Sub-Issue:** #229
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/pygal/line/area-basic/default.py`

## Changes
- Rewrote implementation to follow KISS style guidelines (no functions,
sequential code)
- Uses 4800x2700 dimensions per style guide
- Applied Python Blue color (#306998) from the style palette
- Configured proper font sizes for high-resolution output
- Uses the spec example data (monthly sales)

## Visual Quality
- Title: Present and clear
- Axis Labels: Both X and Y axes properly labeled
- Legend: Present at bottom
- Fill: Area properly filled with transparency
- Dimensions: 4800x2700 px (16:9 aspect ratio)

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **plotnine** library.

**Parent Issue:** #201
**Sub-Issue:** #224
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/plotnine/area/area-basic/default.py`

## Changes
- Simplified to KISS style (no functions, classes, or type hints)
- Uses spec example data (monthly sales)
- Python Blue color palette (#306998)
- Output: 4800x2700px at 300dpi

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **letsplot** library.

**Parent Issue:** #201
**Sub-Issue:** #240
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/letsplot/area/area-basic/default.py`

## Details
- Uses `geom_area()` with Python Blue (#306998) fill color
- Implements proper month labeling via `scale_x_continuous()` with
custom breaks and labels
- Follows the 4800 × 2700 px image size requirement (using ggsize
1600x900 with scale=3)
- Uses `theme_minimal()` with customized font sizes for readability

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **plotly** library.

**Parent Issue:** #201
**Sub-Issue:** #211
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/plotly/scatter/area-basic/default.py`

## Changes
- Simple KISS-style implementation using `go.Scatter` with
`fill='tozeroy'`
- Uses Python Blue (#306998) from the default style guide
- Outputs 4800x2700px image (1600x900 @ scale 3)
- Clean layout with axis labels, title, and subtle grid

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **highcharts** library.

**Parent Issue:** #201
**Sub-Issue:** #234
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/highcharts/area/area-basic/default.py`

## Features
- Basic area chart with filled region between line and x-axis
- Supports both numeric and categorical x-axis values
- Configurable fill opacity and line width
- Grid lines with subtle styling (dotted, low opacity)
- Proper axis labels and title
- Data markers on data points
- PNG export via Selenium screenshot

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **altair** library.

**Parent Issue:** #201
**Sub-Issue:** #219
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/altair/area/area-basic/default.py`

## Details
- Uses `mark_area()` with 0.5 opacity and Python Blue color (#306998)
- Overlays `mark_line()` for visible line on top of area
- Configures axis with subtle grid (opacity 0.3)
- 1600x900 base size with 3x scale factor for 4800x2700 output
- Font sizes: title 20pt, axis labels 20pt, tick labels 16pt

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **highcharts** library.

**Parent Issue:** #201
**Sub-Issue:** #339
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/highcharts/area/area-basic/default.py`

## Changes
- Simple sequential script following KISS principle (no functions,
classes, or type hints)
- Uses Python Blue (#306998) as primary color per style guide
- 4800x2700 px output per style guide
- Inline Highcharts JS for reliable headless Chrome rendering
- Proper `container="container"` specification for chart rendering
- Subtle grid with 10% opacity
- Appropriate font sizes for the large canvas (48px title, 40px axis
titles, 32px labels)

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **pygal** library.

**Parent Issue:** #201
**Sub-Issue:** #337
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/pygal/area/area-basic/default.py`

## Details
- Uses `pygal.Line` with `fill=True` to create area chart effect
- Custom style with project color palette (#306998 Python Blue)
- Output: 4800×2700 px PNG (per style guide)
- Configured with:
- Appropriate font sizes for high-res output (title: 60pt, labels: 48pt)
  - Subtle y-axis grid
  - Transparency (opacity=0.5) for the fill
  - Line stroke width 4px with visible dot markers

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **highcharts** library.

**Parent Issue:** #201
**Sub-Issue:** #396
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/highcharts/area/area-basic/default.py`

## Details
- Uses AreaSeries with fill opacity of 0.5 for appropriate transparency
- Line width of 4px for visibility on top of filled area
- Font sizes scaled appropriately for 4800x2700px output
- Python Blue (#306998) color from style guide
- Monthly sales data as sample data
- Inline Highcharts JS for headless Chrome compatibility

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **letsplot** library.

**Parent Issue:** #201
**Sub-Issue:** #341
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/letsplot/area/area-basic/default.py`

## Changes
- Added separate `geom_line` layer for visible line on top of filled
area
- Uses alpha=0.5 for the area fill as per spec requirements
- Line width of 2 matches style guide recommendations
- Uses Python Blue (#306998) from the color palette
- Output size: 4800 × 2700 px (1600 × 900 base with scale=3)

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **altair** library.

**Parent Issue:** #201
**Sub-Issue:** #395
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/altair/area/area-basic/default.py`

## Changes
- Uses `mark_area()` with inline `line` parameter for cleaner code
- Extended data from 6 to 12 months for richer visualization
- Added `configure_view(strokeWidth=0)` to remove chart border
- Configured proper font sizes for title, axis labels, and tick labels
- Subtle grid with `gridOpacity=0.3`
- Outputs 4800×2700px PNG (1600×900 × scale_factor=3.0)

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **plotly** library.

**Parent Issue:** #201
**Sub-Issue:** #328
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/plotly/scatter/area-basic/default.py`

## Details
- Uses `go.Scatter` with `fill="tozeroy"` for area visualization
- Monthly sales data as example dataset
- Fill color: rgba(48, 105, 152, 0.5) - Python Blue with 50%
transparency
- Line color: #306998 (Python Blue) with width 2
- Proper axis labels and centered title
- Output size: 4800×2700 px (1600×900 with scale=3)
- Subtle grid with alpha 0.1
- Uses plotly_white template for clean appearance

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **highcharts** library.

**Parent Issue:** #201
**Sub-Issue:** #428
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/highcharts/area/area-basic/default.py`

## Features
- Basic area chart with monthly sales data
- Python Blue (#306998) color scheme following style guide
- 4800x2700 px output size
- Proper axis labels with readable font sizes
- Subtle grid (0.1 opacity)
- Markers on data points
- 50% fill opacity for area

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

## Summary
Implements `area-basic` for **bokeh** library.

**Parent Issue:** #201
**Sub-Issue:** #215
**Base Branch:** `plot/area-basic`
**Attempt:** 2/3

## Implementation
- `plots/bokeh/varea/area-basic/default.py`

## Details
- Uses `varea` method for filled area chart
- Includes `line` overlay for clearer boundary
- Monthly sales data from the spec (Jan-Dec)
- Categorical x-axis with month label overrides
- Python Blue (#306998) color with 70% opacity fill
- 4800x2700px output per style guide
- Font sizes: 20pt for title/axis labels, 16pt for tick labels
- Subtle grid with 0.3 alpha

## Dependencies
Added `selenium>=4.15.0` and `webdriver-manager>=4.0.0` to `lib-bokeh`
optional dependency in `pyproject.toml`. This is required for bokeh's
`export_png()` function.

## ⚠️ CI Fix Required (Workflow Permission)
The CI workflow needs Chrome setup for bokeh tests (similar to
highcharts). A maintainer needs to update
`.github/workflows/ci-plottest.yml`:

**Change line 69-71 from:**
```yaml
- name: Setup Chrome for Highcharts
  if: steps.detect_libs.outputs.has_plots == 'true' && contains(steps.detect_libs.outputs.libraries, 'highcharts')
```

**To:**
```yaml
- name: Setup Chrome for Bokeh/Highcharts
  if: steps.detect_libs.outputs.has_plots == 'true' && (contains(steps.detect_libs.outputs.libraries, 'highcharts') || contains(steps.detect_libs.outputs.libraries, 'bokeh'))
```

This cannot be pushed from this workflow due to GitHub App workflow
permissions.

## Local Test Result
The implementation runs successfully locally with Chrome and produces a
valid 4800x2700 PNG.

---------

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Markus Neusinger <2921697+MarkusNeusinger@users.noreply.github.com>

## Summary
Implements `area-basic` for **pygal** library.

**Parent Issue:** #201
**Sub-Issue:** #427
**Base Branch:** `plot/area-basic`
**Attempt:** 4/3

## Implementation
- `plots/pygal/area/area-basic/default.py`

## Features
- Creates a filled area chart using pygal's Line chart with `fill=True`
- Uses PyPlots color palette (#306998 - Python Blue)
- 4800x2700 pixel output (16:9 aspect ratio)
- Custom style with appropriate font sizes for readability
- Clean axes labels (Month, Sales ($))
- Subtle grid on Y-axis

## Fix for CI Issue
Previous attempts failed because:
1. The base branch has a duplicate file at
`plots/pygal/line/area-basic/default.py`
2. Deleting this duplicate caused CI to try to test the deleted file
(which doesn't exist)

This attempt keeps only the correct `area/` implementation in the diff
without touching the `line/` duplicate. The duplicate should be cleaned
up separately.

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Markus Neusinger <2921697+MarkusNeusinger@users.noreply.github.com>

## Summary
Implements `area-basic` for **highcharts** library.

**Parent Issue:** #201
**Sub-Issue:** #473
**Base Branch:** `plot/area-basic`
**Attempt:** 1/3

## Implementation
- `plots/highcharts/area/area-basic/default.py`

## Features
- Basic area chart showing monthly sales trend
- Python Blue (#306998) color scheme
- Filled area with 50% opacity
- Visible markers on data points
- Subtle grid lines (10% opacity)
- Full x-axis labels (Jan-Dec) and y-axis label (Sales $)
- 4800x2700px output via Selenium screenshot

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>