CEO业绩三维气泡图（高级图表）

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    import numpy as np
    
    url = 'https://liangdaima.com/static/data/wooldridge/ceosal1.csv'
    df = pd.read_csv(url)
    
    plt.figure(figsize=(12,8))
    plt.scatter(df['roe'], df['salary'], s=df['sales']/50, alpha=0.5, c='purple')
    plt.xscale('log')
    plt.yscale('log')
    plt.title('CEO业绩气泡图（气泡大小=销售额）', fontsize=14)
    plt.xlabel('ROE（%）', fontsize=12)
    plt.ylabel('薪资（千美元）', fontsize=12)
    plt.grid(alpha=0.3)
    plt.tight_layout()
    plt.show()
    return "可视化代码执行完成"