fix(seaborn): address review feedback for line-retention-cohort

Attempt 1/3 - fixes based on AI review

Author: github-actions[bot]

plots/line-retention-cohort/implementations/seaborn.py

@@ -1,4 +1,4 @@
-""" pyplots.ai
+"""pyplots.ai
 line-retention-cohort: User Retention Curve by Cohort
 Library: seaborn 0.13.2 | Python 3.14.3
 Quality: 84/100 | Created: 2026-03-16
@@ -33,28 +33,46 @@
 
 df = pd.DataFrame(records)
 
-# Plot
-palette = ["#8FAABC", "#7B9EA8", "#306998", "#2A7F62", "#1B9E77"]
-linewidths = [1.8, 2.0, 2.5, 2.8, 3.2]
+# Plot - use seaborn style, context, and hue-based grouping
+sns.set_theme(
+    style="whitegrid",
+    rc={
+        "axes.spines.top": False,
+        "axes.spines.right": False,
+        "grid.alpha": 0.15,
+        "grid.linewidth": 0.8,
+        "axes.grid.axis": "y",
+    },
+)
+sns.set_context("talk", font_scale=1.1)
+
+palette = sns.color_palette("colorblind", n_colors=5)
 
 fig, ax = plt.subplots(figsize=(16, 9))
 
-for i, cohort_label in enumerate(df["cohort"].unique()):
-    cohort_data = df[df["cohort"] == cohort_label]
-    sns.lineplot(
-        data=cohort_data,
-        x="week",
-        y="retention",
-        label=cohort_label,
-        color=palette[i],
-        linewidth=linewidths[i],
-        marker="o",
-        markersize=6 + i,
-        ax=ax,
-    )
-
-ax.axhline(y=20, color="#999999", linestyle="--", linewidth=1.2, alpha=0.6)
-ax.text(12.2, 20, "20% target", fontsize=13, color="#999999", va="center")
+sns.lineplot(
+    data=df,
+    x="week",
+    y="retention",
+    hue="cohort",
+    style="cohort",
+    markers=True,
+    dashes=False,
+    palette=palette,
+    linewidth=2.5,
+    markersize=8,
+    ax=ax,
+)
+
+cohort_labels = df["cohort"].unique()
+for i, line in enumerate(ax.lines[: len(cohort_labels)]):
+    weight = 1.5 + i * 0.4
+    line.set_linewidth(weight)
+    line.set_markersize(5 + i * 1.5)
+    line.set_alpha(0.5 + i * 0.12)
+
+ax.axhline(y=20, color="#888888", linestyle="--", linewidth=1.2, alpha=0.5, zorder=1)
+ax.text(12.3, 20, "20% target", fontsize=13, color="#888888", va="center", fontstyle="italic")
 
 # Style
 ax.set_title("line-retention-cohort · seaborn · pyplots.ai", fontsize=24, fontweight="medium", pad=20)
@@ -66,11 +84,8 @@
 ax.set_ylim(0, 105)
 ax.set_xticks(weeks)
 
-ax.spines["top"].set_visible(False)
-ax.spines["right"].set_visible(False)
-ax.yaxis.grid(True, alpha=0.2, linewidth=0.8)
-
-ax.legend(fontsize=14, frameon=False, loc="upper right", title="Signup Cohort", title_fontsize=15)
+legend = ax.legend(fontsize=14, frameon=False, loc="upper right", title="Signup Cohort", title_fontsize=15)
+legend.get_title().set_fontweight("semibold")
 
 plt.tight_layout()
 plt.savefig("plot.png", dpi=300, bbox_inches="tight")