Hey there! Let's tackle your two questions about Material-UI v5's styling package differences and import strategies clearly:

The two packages serve distinct purposes, tied to MUI's transition from v4 to v5:

• Modern vs. Legacy Tooling:
  • @mui/material/styles is the official, recommended styling package for MUI v5. It’s built specifically to integrate with v5’s updated component system, including support for the new ThemeProvider, useTheme hook, createTheme (which replaces v4’s createMuiTheme), and the styled utility that works seamlessly with MUI’s core components. It’s where all the new styling features live.
  • @mui/styles is the legacy styling solution carried over from MUI v4. It’s maintained solely for backward compatibility—so if you’re migrating a v4 app that relied on makeStyles, useStyles, or withStyles, this is where those functions now live. It doesn’t integrate tightly with v5’s new component features and won’t receive major updates going forward.
• Core Integration:
  • @mui/material/styles is deeply tied to the main MUI core library (@mui/material). It’s designed to work hand-in-hand with MUI components, leveraging v5’s theme structure and component props directly.
  • @mui/styles is a standalone package that doesn’t depend on @mui/material—you could technically use it with other UI libraries, but that’s not its intended use case. It uses the older theme structure from v4, though it can be adapted to work with v5 themes if necessary.
• Feature Set:
  • @mui/material/styles includes all of v5’s modern styling enhancements, like responsive values out of the box, more flexible theme customization with createTheme, and tight integration with MUI’s system props (like the sx prop).
  • @mui/styles lacks these newer features; it’s limited to the styling capabilities from v4, so you won’t get the same level of synergy with v5’s component ecosystem.

Unfortunately, you can’t import all styling APIs from a single package in MUI v5. Here’s the breakdown:

• Modern tools like useTheme, createTheme, and styled are only available in @mui/material/styles.
• Legacy tools like makeStyles, useStyles, and withStyles are exclusively housed in @mui/styles.

If you’re starting a new project with MUI v5, the best practice is to stick entirely with @mui/material/styles and use its modern utilities (like the styled utility or the sx prop) instead of relying on legacy makeStyles. For migration projects moving from v4 to v5, you’ll need to use both packages temporarily: keep @mui/styles for your existing makeStyles code while gradually refactoring to the newer tools in @mui/material/styles.

内容的提问来源于stack exchange，提问作者Edward Lee