Paper 纸张组件
在 Material Design 中，我们在屏幕上展现了纸张的物理属性。
The background of an application resembles the flat, opaque texture of a sheet of paper, and an application's behavior mimics paper's ability to be re-sized, shuffled, and bound together in multiple sheets.
<Paper elevation={0} />
<Paper />
<Paper elevation={3} /><Paper variant="outlined" />
<Paper variant="outlined" square />