<filename>app.py
import dash
import dash_bootstrap_components as dbc
#external_stylesheets=[dbc.themes.SUPERHERO]
external_stylesheets=[dbc.themes.GRID]
app = dash.Dash(__name__,external_stylesheets = external_stylesheets, suppress_callback_exceptions=True)

<filename>app.py
import dash
import dash_bootstrap_components as dbc
#external_stylesheets=[dbc.themes.SUPERHERO]
external_stylesheets=[dbc.themes.GRID]
app = dash.Dash(__name__,external_stylesheets = external_stylesheets, suppress_callback_exceptions=True)

#external_stylesheets=[dbc.themes.SUPERHERO]