Sorry Julie but i can't understand witch CSS is not correct. I have look to your website a long time and didn't see any problem with CSS.
The only thing i found was in the chrome inspector :
gallery-static.html:10 Mixed Content: The page at '
https://thetaooftype.com/gallery-static.html' was loaded over HTTPS, but requested an insecure stylesheet '
http://fonts.googleapis.com/css?family=Oswald:400,300,700'. This request has been blocked; the content must be served over HTTPS.
For this you just have to follow Andy suggestion (without http request) :
<link href='//fonts.googleapis.com/css?family=Oswald:400,300,700' rel='stylesheet' type='text/css'>
gallery-static.html:31 Mixed Content: The page at '
https://thetaooftype.com/gallery-static.html' was loaded over HTTPS, but requested an insecure image '
http://thetaooftype.com/assets/img/logo.png'. This content should also be served over HTTPS.
https://thetaooftype.com/ne.html Failed to load resource: the server responded with a status of 404 (Not Found)
For this one, on line 31 you have to change this :
<a href="https://thetaooftype.com/"><img src="http://thetaooftype.com/assets/img/logo.png" alt="The Tao of Type"/></a>
to this with http
S://thetaooftype.com/assets/img/logo.png
<a href="https://thetaooftype.com/"><img src="https://thetaooftype.com/assets/img/logo.png" alt="The Tao of Type"/></a>
EDIT : For https check your config.inc.php in core/config folder there is 2 line where you can setup http_host