Perhaps you have been in this situation. Busy building your streamlit app on you 17inch wide laptop. Everything looks fly:
Then you realise users might access your app from their tablet or phone. So you open up your developer tools not expecting much of a change only to see:
Perhaps if I had a way to tell what the screen size is and when it changes to show different types of an app. You could use st_javascript to get the screen width size at the start of your app using some javascript or streamlit_js_eval which seems much simpler. In addition to these options, I created a library that pulls some important screen data based on dynamic changes to the screen that looks like:
You can use these to conditionally render different formats/version of your app.
The demo app is here, the github repo and the pypi.
Happy streamliting.