hey steve,
I'm not sure if i see a different website because I'm not logged in or something like that, but as I mentioned in other posts it seems that the website you are referencing doesn't have lay theme installed from my point of view.
This is what i see:
Screen Shot 2016-07-18 at 15.48.12.png
For doing style changes it's best to use the fields in "Lay Options" -> "Custom CSS and HTML"
There you have the fields "custom css for desktop" and "custom css for phone".
If you want to create a style that applies to both desktop and phone you could add your style in a <style> tag like this to the field "Custom <head> content":
<style>
.hello{
opacity: 0.5;
}
</style>
I'm not sure what you did with the original style.css file but if you delete the first few lines of that file the theme will probably not work right because in those lines there's vital info about the theme like name, version etc. (that's standardized by wordpress)