Express vs Standard Shipping

import numpy as np
import matplotlib.pyplot as plt
from scipy.stats import gaussian_kde

np.random.seed(1983)
BG_COLOR = '#0a0a0f'
TEXT_COLOR = 'white'

express = np.random.gamma(2, 0.5, 800) + 1
standard = np.random.gamma(3, 1.5, 1000) + 3
express = express[express < 6]
standard = standard[(standard > 2) & (standard < 15)]

fig, ax = plt.subplots(figsize=(12, 7), facecolor=BG_COLOR)
ax.set_facecolor(BG_COLOR)

x = np.linspace(0, 15, 400)

kde_e = gaussian_kde(express)
y_e = kde_e(x)
ax.fill_between(x, y_e, alpha=0.3, color='#6CF527')
ax.plot(x, y_e, color='#6CF527', linewidth=4, alpha=0.3)
ax.plot(x, y_e, color='#6CF527', linewidth=2, label='Express Shipping')

kde_s = gaussian_kde(standard)
y_s = kde_s(x) * -1
ax.fill_between(x, y_s, alpha=0.3, color='#F5276C')
ax.plot(x, y_s, color='#F5276C', linewidth=4, alpha=0.3)
ax.plot(x, y_s, color='#F5276C', linewidth=2, label='Standard Shipping')

ax.axhline(0, color='#333', linewidth=1.5)

med_e = np.median(express)
med_s = np.median(standard)
ax.axvline(med_e, color='#6CF527', linestyle='--', linewidth=1.5, alpha=0.7)
ax.axvline(med_s, color='#F5276C', linestyle='--', linewidth=1.5, alpha=0.7)

time_saved = med_s - med_e
pct_faster = (time_saved / med_s) * 100

stats_text = 'Delivery Time:\nExpress: %.1f days median\nStandard: %.1f days median\nTime saved: %.1f days' % (med_e, med_s, time_saved)
ax.text(0.02, 0.98, stats_text.replace('\n', chr(10)), transform=ax.transAxes, fontsize=10,
        color=TEXT_COLOR, verticalalignment='top', fontfamily='monospace',
        bbox=dict(boxstyle='round,pad=0.5', facecolor='#1a1a2e', edgecolor='#333', alpha=0.9))

ax.text(0.98, 0.98, 'Express is %.0f%% faster' % pct_faster, 
        transform=ax.transAxes, fontsize=11, color='#6CF527', ha='right', va='top', fontweight='bold')

ax.set_xlabel('Delivery Time (days)', fontsize=12, color=TEXT_COLOR, fontweight='500')
ax.set_ylabel('Density', fontsize=12, color=TEXT_COLOR, fontweight='500')
ax.set_title('E-Commerce Delivery: Express vs Standard', fontsize=14, 
             color=TEXT_COLOR, fontweight='bold', pad=15)

ax.tick_params(colors='#888', labelsize=10)
for spine in ax.spines.values():
    spine.set_color('#333')

ax.legend(loc='upper right', facecolor='#1a1a2e', edgecolor='#333', 
          labelcolor=TEXT_COLOR, fontsize=10)
ax.set_xlim(0, 15)
plt.tight_layout()
plt.show()