Hi @qxlsz,
Currently it’s not possible to set title and header alignment. Our layout is done in Markdown which doesn’t contain a native notion of text alignment (it’s all left-justified by default).
Additionally I don’t think it will work to use HTML to force the alignment, since the style will get overridden by Streamlit’s CSS. (I am not great at CSS, though; maybe it’s possible with some HTML/CSS wizardry?)
If this is an important feature for you, I recommend opening a Feature Request in our github issues.