I have seem a lot of videos in which developers are changing CSS on the fly in chrome. I tried the same thing but chrome did not allow me to change the code. I can't write on the style sheet.
Is there any specific setting to do this? Kindly help.
EDIT: To edit the CSS, I right click on an element, select inspect element. It will open the console. I select the id of the element and go to style.css in Resources and try to change the CSS. It does not allow me to write there.
You are doing it wrong... the resources panel is not there for live edit, if you want to change the css associated with an HTML element, right click on that element and then in the right panel you will see the css styles associated with the selected element. You can edit that rules and you will see the changes in real time.
Maybe you can check some videos to learn some basics about the Chrome Developer Tools, and after that if you want to learn more, you can check this question:
Chrome Developer Tools: Best resource for learning advanced features?