About: http://webisa.webdatacommons.org/281925396

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	So it seems h1 is a block element, and text-align does not center block elements, it only centers inline elements inside it, which explains the centered off-center behavior.
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com