Caffeine vs Reaction Time

import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
import pandas as pd

np.random.seed(415)
BG_COLOR = '#ffffff'
TEXT_COLOR = '#1f2937'

n = 60
caffeine = np.random.uniform(0, 400, n)
reaction = 350 - 0.3 * caffeine + np.random.normal(0, 30, n)
reaction = np.clip(reaction, 150, 450)

df = pd.DataFrame({'Caffeine (mg)': caffeine, 'Reaction Time (ms)': reaction})

fig, ax = plt.subplots(figsize=(10, 6), facecolor=BG_COLOR)
ax.set_facecolor(BG_COLOR)

sns.regplot(
    data=df,
    x='Caffeine (mg)',
    y='Reaction Time (ms)',
    scatter_kws={'color': '#27D3F5', 'alpha': 0.6, 's': 55, 'edgecolor': 'white', 'linewidths': 0.5},
    line_kws={'color': '#F5276C', 'linewidth': 2.5},
    ci=95,
    ax=ax
)

for collection in ax.collections[1:]:
    collection.set_facecolor('#F5276C')
    collection.set_alpha(0.15)

ax.axvspan(200, 400, alpha=0.08, color='#ef4444')
ax.text(300, 420, 'High Intake', color='#ef4444', fontsize=9, ha='center')

corr = np.corrcoef(caffeine, reaction)[0, 1]
ax.text(0.05, 0.05, 'r = %.3f' % corr, transform=ax.transAxes, fontsize=12,
        color='#F5276C', fontweight='bold', va='bottom',
        bbox=dict(boxstyle='round,pad=0.3', facecolor='#f8fafc', edgecolor='#e5e7eb'))

ax.set_xlabel('Caffeine Intake (mg)', fontsize=12, color=TEXT_COLOR, fontweight='500')
ax.set_ylabel('Reaction Time (ms)', fontsize=12, color=TEXT_COLOR, fontweight='500')
ax.set_title('Caffeine vs Reaction Time', fontsize=14, color=TEXT_COLOR, fontweight='bold', pad=15)

ax.tick_params(colors='#374151', labelsize=10)
for spine in ax.spines.values():
    spine.set_color('#e5e7eb')

plt.tight_layout()
plt.show()