Nextjs
Reference
Container
The container aligns your content horizontally at the center. It serves as a fundamental layout component.
Although containers can be nested, most layouts do not necessitate nested containers.
Fluid
The width of a fluid container is constrained by the value of the 
maxWidth prop.import * as React from 'react';
import CssBaseline from '@mui/material/CssBaseline';
import Box from '@mui/material/Box';
import Container from '@mui/material/Container';
export default function SimpleContainer() {
  return (
    <React.Fragment>
      <CssBaseline />
      <Container maxWidth="sm">
        <Box sx={{ bgcolor: '#cfe8fc', height: '100vh' }} />
      </Container>
    </React.Fragment>
  );
}<Container maxWidth="sm">
Fixed
For designs that prioritize a fixed set of sizes over a fully fluid viewport, you can apply the 
fixed prop. This sets the maximum width to match the minimum width of the current breakpoint.import * as React from 'react';
import CssBaseline from '@mui/material/CssBaseline';
import Box from '@mui/material/Box';
import Container from '@mui/material/Container';
export default function FixedContainer() {
  return (
    <React.Fragment>
      <CssBaseline />
      <Container fixed>
        <Box sx={{ bgcolor: '#cfe8fc', height: '100vh' }} />
      </Container>
    </React.Fragment>
  );
}<Container fixed>