app.py

import streamlit as st 
#from streamlit_navigation_bar import st_navbar


header = st.container()
header.title("Here is a sticky header")
header.write("""<div class='fixed-header'/>""", unsafe_allow_html=True)

### Custom CSS for the sticky header
st.markdown(
    """
<style>
    div[data-testid="stVerticalBlock"] div:has(div.fixed-header) {
        position: sticky;
        top: 2.875rem;
        background-color: white;
        z-index: 999;
    }
    .fixed-header {
        border-bottom: 1px solid black;
    }
</style>
    """,
    unsafe_allow_html=True
)







   # --- SHARED ON ALL PAGES ---
st.logo(image="images/menu_book_60dp_75FBFD.png")
st.sidebar.title("SBS V2.0 mapper")
st.sidebar.subheader("(work in progress)")
st.sidebar.text("Demo by JA-RAD")

# --- PAGE SETUP ---
type_text_page = st.Page(
    page="pages/type_text.py",
    title="SBS V2.0 mapper",
    icon=":material/keyboard:",
    default=True,)

# --- NAVIGATION SETUP ---

pg = st.navigation(pages=[type_text_page]) # WITHOUT SECTIONS
#pg = st.navigation({"Chapter_Index": [start_page], "Demo": [type_text_page, upload_file_page], "About": [about_page]}) # WITH SECTIONS
pg.run() 
#page = st_navbar(pages=["SBS V2.0 mapper"], selected="SBS V2.0 mapper", key="app_page_navbar")
#st.write(page)