My current web site is 960px wide, and I am looking to switch it over to a responsive layout for tablets and phones. I looked-up some stuff on RWD over the weekend, and I have a good idea of RWD. I just have a few questions to clear-up somethings.

1. Is it better to set the container to a fixed or to a percentage width in @media screen and (max-width ) section of my CSS file?

2. How do you deal with tablets and phones that have high pixel density? 1080P on a desktop screen is a lot different then a 1080P on a phone.