Install web developer extension in chrome.
Go to any site. Open web developer extension >> CSS > Edit css
Now you can edit the css and see the live effects of the css changes. You can literally change the look of the overall website / make it elegant / make it professional in an hour because of this extension.
And even if you are not a developer, playing around with the extension ensures you come to know basics of css and you dont break anything on a live website.
Not only css, the extension helps in many things. Try it out.