I'm currently working on an iOS app using Ionic, and my main responsibility is handling the CSS. I've noticed that the design varies significantly between testing on an iPhone 4/4s and on a 6+. It's challenging to create one design that works well on both versions of the phone, so I find myself making adjustments to the CSS based on the device it will run on. What would be the most effective approach to tackle this issue?
At the moment, the app appears fine on an iPhone 5, but there are some issues with excessive spacing on the 6+ and overcrowding on the 4/4s, which sometimes leads to scroll/button overlap due to screen size differences.