Stylesheet font-family change not working

Hi, apologies for requesting assistance with the most basic of customisation issues. I’ve followed previous help topics about changing font families in the stylesheet using css, but I’m not seeing any changes to my site.

The website is https://www.adamtassle.c0m (please replace 0 with o)

I’m attempting to switch from “Trebuchet MS” to Tahoma for the default website / blog font. I’ve changed the body font-family in style.css and checked with ctrl-f that there are no remaining references to “Trebuchet MS”, but the site still appears to me to be rendered in Trebuchet.

Am I missing something glaringly obvious?

Cheers,
Adam