REM and mobile-side layouts

Mobile layout pain points in: compatible with each resolution of mobile devices, the same mobile phone, Iphone4-iphonex resolution range is already very wide, if the use of PX layout, obviously there will be problems;

Common pixel unit Px,em,rem, EM is relative to the parent element font-size units, the individual think in use, EM will be more chaotic; REM is relative to the root element, HTML, easy to layout according to the screen resolution;

The current mobile-side layout takes the form of: "Horizontal percent + longitudinal rem", while using the flex layout, media queries;

Https://www.cnblogs.com/ysshuai/p/6694339.html

Https://www.cnblogs.com/mracale/p/7170385.html

Https://www.cnblogs.com/jide/p/7051006.html

REM and mobile-side layouts