Plotly:如何使用datetime索引绘制一个以线为中心的范围？

import plotly.graph_objects as go
import pandas as pd

df = pd.DataFrame({
    'date': ['2022-01-01', '2022-01-02', '2022-01-03', '2022-01-04'],
    'value': [10, 15, 7, 12]
})
df['date'] = pd.to_datetime(df['date'])
df.set_index('date', inplace=True)

fig = go.Figure()

# 添加线
fig.add_trace(go.Scatter(
    x=df.index,
    y=df['value'],
    mode='lines',
    name='Value'
))

# 添加范围
fig.add_trace(go.Scatter(
    x=df.index,
    y=[df['value'].min(), df['value'].max()],
    fill='tonexty',
    mode='none',
    name='Range'
))

fig.update_layout(
    title='Plotly Line with Range',
    xaxis_title='Date',
    yaxis_title='Value',
    showlegend=True
)

fig.show()