feat(pygal): implement radar-multi (#10299)

## Implementation: `radar-multi` - python/pygal

Implements the **python/pygal** version of `radar-multi`.

**File:** `plots/radar-multi/implementations/python/pygal.py`

**Parent Issue:** #2026

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/32046977179)*

---------

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

Author: github-actions[bot]

plots/radar-multi/implementations/python/pygal.py

@@ -1,62 +1,90 @@
 """ anyplot.ai
 radar-multi: Multi-Series Radar Chart
-Library: pygal 3.1.0 | Python 3.13.13
-Quality: 86/100 | Updated: 2026-05-07
+Library: pygal 3.1.3 | Python 3.13.15
+Quality: 90/100 | Updated: 2026-08-17
 """
 
+import os
+
 import pygal
 from pygal.style import Style
 
 
+# Theme tokens (see prompts/default-style-guide.md "Background" + "Theme-adaptive Chrome")
+THEME = os.getenv("ANYPLOT_THEME", "light")
+PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
+INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
+INK_MUTED = "#6B6A63" if THEME == "light" else "#A8A79F"
+
+# Imprint categorical palette — position 1 is always the brand green
+IMPRINT_PALETTE = ("#009E73", "#C475FD", "#4467A3", "#BD8233", "#AE3030", "#2ABCCD", "#954477", "#99B314")
+
 # Data - Team performance comparison across skill dimensions
 categories = ["Communication", "Technical", "Leadership", "Creativity", "Teamwork", "Problem Solving"]
-teams = {
-    "Alpha Team": [85, 90, 75, 80, 88, 82],
-    "Beta Team": [78, 72, 85, 90, 70, 88],
-    "Gamma Team": [65, 88, 70, 75, 92, 78],
-}
+teams = [
+    ("Alpha Team", [85, 90, 75, 80, 88, 82]),
+    ("Beta Team", [78, 72, 85, 90, 70, 88]),
+    ("Gamma Team", [65, 88, 70, 75, 92, 78]),
+]
 
-# Custom style for 3600x3600 canvas (square for radar)
+# Highest overall average becomes the visual "hero" series — a bolder, solid
+# stroke and larger dots build a focal point so the viewer immediately spots
+# the top all-round team, while the other two recede behind a thinner dashed
+# outline.
+hero_name, _ = max(teams, key=lambda t: sum(t[1]) / len(t[1]))
+
+# Style — theme-adaptive chrome, Imprint palette, sizing tuned for the 2400x2400 canvas
 custom_style = Style(
-    background="white",
-    plot_background="white",
-    foreground="#333333",
-    foreground_strong="#333333",
-    foreground_subtle="#666666",
-    colors=("#306998", "#FFD43B", "#E74C3C"),
-    title_font_size=72,
-    label_font_size=42,
-    major_label_font_size=36,
-    legend_font_size=42,
-    value_font_size=32,
+    font_family='"Liberation Sans", "DejaVu Sans", Arial, sans-serif',
+    background=PAGE_BG,
+    plot_background=PAGE_BG,
+    foreground=INK,
+    foreground_strong=INK,
+    foreground_subtle=INK_MUTED,
+    colors=IMPRINT_PALETTE,
+    title_font_size=66,
+    label_font_size=56,
+    major_label_font_size=44,
+    legend_font_size=44,
+    value_font_size=36,
     opacity=0.25,
     opacity_hover=0.5,
 )
 
-# Create radar chart
+# Plot — square canvas for the symmetric radar layout. Legend moved to the
+# bottom (rather than the default left column) so the polar plot area is no
+# longer squeezed toward the top-right of the canvas, balancing whitespace.
 chart = pygal.Radar(
-    width=3600,
-    height=3600,
+    width=2400,
+    height=2400,
     style=custom_style,
-    title="radar-multi · pygal · pyplots.ai",
+    title="radar-multi · python · pygal · anyplot.ai",
     show_legend=True,
-    legend_at_bottom=False,
-    legend_box_size=30,
-    dots_size=12,
-    stroke_style={"width": 5},
+    legend_at_bottom=True,
+    legend_at_bottom_columns=3,
     show_dots=True,
     fill=True,
     inner_radius=0.1,
     range=(0, 100),
+    margin=30,
+    spacing=16,
 )
-
-# Set axis labels
 chart.x_labels = categories
 
-# Add data series
-for team_name, values in teams.items():
-    chart.add(team_name, values)
+# Add data series — hero team gets a bold solid stroke + larger dots, the
+# other two recede behind a thinner dashed outline.
+for team_name, values in teams:
+    is_hero = team_name == hero_name
+    chart.add(
+        team_name,
+        values,
+        dots_size=12 if is_hero else 7,
+        stroke_style={"width": 6, "linecap": "round", "linejoin": "round"}
+        if is_hero
+        else {"width": 2.5, "linecap": "round", "linejoin": "round", "dasharray": "12,6"},
+    )
 
-# Save outputs
-chart.render_to_png("plot.png")
-chart.render_to_file("plot.html")
+# Save
+chart.render_to_png(f"plot-{THEME}.png")
+with open(f"plot-{THEME}.html", "wb") as f:
+    f.write(chart.render())