Ploty and implementation of CSS

How could be a CSS code added to the code below?
Every time i update the code with CSS i have got on line

format(plotlyjs=get_plotlyjs(), div1=div1, div2=div2)

error. KeyError: ‘background-color’

import plotly.graph_objs as go
from plotly.offline import plot, get_plotlyjs
fig1 = go.Figure(data=[{‘type’: ‘bar’, ‘y’: [1, 3, 2]}],
… layout={‘height’: 400})
fig2 = go.Figure(data=[{‘type’: ‘scatter’, ‘y’: [1, 3, 2]}],
… layout={‘height’: 400})
div1 = plot(fig1, output_type=‘div’, include_plotlyjs=False)
div2 = plot(fig2, output_type=‘div’, include_plotlyjs=False)

html = ‘’’

              <style>
              body {background-color: powderblue;}
              h1   {color: blue;}
              p    {color: red;}
             </style>




… {div1}
… {div2}


…‘’'.format(plotlyjs=get_plotlyjs(), div1=div1, div2=div2)

with open(‘multi_plot.html’, ‘w’) as f:
… f.write(html)