If nothing else, it can be said that the purpose of the viewport is to tame the mobile browser window. The viewport is vital to determining how your mobile browser renders the mobile web page.
If you are using an Apple computer, an iOS simulator can be obtained by downloading Xcode from Apple. It is part of the Xcode package. I usually get to it by using Spotlight. Press Command + the Space bar; the Spotlight search field appears in the top-right corner of your screen. Start typing in
iOS Simulator, and it will appear in the search results. Click on it to spin up the iOS simulator.
Open up one of the responsive projects that you've done from a previous recipe project. I suggest opening ...