Control Text Width

Here’s the link to the website I am currently working on.

https://emmauscenter.org/

Is there code that I can put in to control the width of the font on the front page. I want it to match the width of the embeded video which is 800px.

Here’s an example of the code for one paragraph of text:

<p style=”text-align: center;”>Our mission for Emmaus Center is to create an environment that promotes spiritual and personal growth for individuals, families and groups on life’s journey toward Christ.</p>

Is there something that can be included in the “text-align: center” that would limit the width of the text to 800px?

Thanks