Centering block of text (simple question, sorry)

how can I center the blocks of text on this page?

https://factualfiction.com/lighthouse/listenwhileudraw/

On the first two paragraphs I’m trying to use with varied results:

p.blocktext {
   	float: none;
   	margin-left: auto;
 	margin-right: auto;
 	width: 200em;
}

with:

<p class="blocktext"> etc </p>

thank you