Pandas styling - change font size and format float/apply background gradient - pandas

Question

I am building an application that displays stock correlations data in various visual forms, including a matrix with a heatmap applied. My heatmap is created by passing the correlation matrix dataframe into IPy Widgets Output, so I can display it as part of a VBox later on. I have successfully applied a background gradient and formatted my numbers to 2dp. Can anyone help me edit the function to also reduce the font size, I just want to shrink it up a little?
Note: I chose to do this using dataframe styling over matplotlib as I had a number of issues getting the output to display in the way I wanted. I also have a function that downloads the dataframe to excel with the styling applied.
I have tried putting the following line of code at the beginning of my notebook so I can leave it outside of the function, but it seems to get ignored once the dataframe is passed to Output.
pd.options.display.float_format = "{:,.2f}".format
Here is my code sample:
import seaborn as sns
import ipywidgets as ipw
import pandas as pd
import numpy as np
#Sample Data
data = np.random.randint(5,30,size=500)
df = pd.DataFrame(data.reshape((50,10)))
corr = df.corr()
#Function produces dataframe as Output
def output_heatmap_df(df):
out = ipw.Output()
with out:
display(df.style\
.background_gradient(cmap=sns.diverging_palette(220,10, as_cmap=True),axis=None).format("{:,.2f}"))
out.layout.width='1600px'
return out
output_heatmap_df(corr)

Answer 1

In case anyone should come across this, the below code worked for me in the end:
def output_heatmap_df(df):
out = ipw.Output()
with out:
display(df.style\
.background_gradient(cmap=sns.diverging_palette(220,10, as_cmap=True),axis=None).format("{:,.2f}")
.set_properties(**{'text-align':'center','font-size':'10px'})
.set_table_styles([{'selector':'th','props':[('text-align','center'),('font-size','10px')]}])
)
out.layout.width='1600px'
return out