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README.md

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 **A flutter plugin for adapting screen and font size.Let your UI display a reasonable layout on different screen sizes!**
 
+*Note*: This plugin is still under development, and some APIs might not be available yet.
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 [中文文档](https://github.com/OpenFlutter/flutter_screenutil/blob/master/README_CN.md)
 
 github: https://github.com/OpenFlutter/flutter_screenutil