It is possible to get rid of that expanse of whitespace at the top of Streamlit apps

streamlit_remove_top_of_page_whitespace.py

# 
# It's a bit of a CSS hack but it is possible to get rid of that
# large amount of whitespace at the top of Streamlit apps!
#
# If this hack stops working, it's likely the Streamlit app CSS
# classes have changed. Open up dev tools and find the new names
# to update the CSS below. :-)
#
# UPDATED 29/4/2022 with new classes
# 

####################################
# *** Put this code in common.py ***

BACKGROUND_COLOR = 'white'
COLOR = 'black'

def set_page_container_style(
        max_width: int = 1100, max_width_100_percent: bool = False,
        padding_top: int = 1, padding_right: int = 10, padding_left: int = 1, padding_bottom: int = 10,
        color: str = COLOR, background_color: str = BACKGROUND_COLOR,
    ):
        if max_width_100_percent:
            max_width_str = f'max-width: 100%;'
        else:
            max_width_str = f'max-width: {max_width}px;'
        st.markdown(
            f'''
            <style>
                header {{
                    visibility: hidden;
                    height: 0%;
                }}
                div[class="css-1adrfps e1fqkh3o2"] {{
                    {max_width_str}
                    padding-top: {padding_top}px;
                }}
                div[class="block-container css-12oz5g7 egzxvld2"] {{
                    {max_width_str}
                    padding-top: {padding_top}px;
                    padding-right: {padding_right}px;
                    padding-left: {padding_left}px;
                    padding-bottom: {padding_bottom}px;
                }}
                div[class="css-1adrfps e1fqkh3o2"] {{
                    color: {color};
                    background-color: {background_color};
                }}
                .appview-container {{
                    color: {color};
                    background-color: {background_color};
                }}
            </style>
            ''',
            unsafe_allow_html=True,
        )

#################################
# *** Put this code in app.py ***

import streamlit as st
from common import set_page_container_style

st.set_page_config(
    page_title='My App',
    layout='wide',
    page_icon=':rocket:'
)

set_page_container_style(
        max_width = 1100, max_width_100_percent = True,
        padding_top = 0, padding_right = 10, padding_left = 5, padding_bottom = 10
)

def about():
    st.sidebar.markdown('---')
    st.sidebar.info('''
    ### Mega App

    Updated: 26 November, 2021''')

if __name__ == '__main__':
    # st.sidebar.image('./images/logo.png', output_format='png')
    st.title('My Mega App')
    about()