Cannot override Material UI Typography fontWeight - material-ui

Question

I just started using Material UI and learning to customize the default theme. I tried changing default palette color and it worked but overriding the typography property was not working.
I am trying to fontWeight property of h3 variant. The default fontWeight for h3 variant is 400. I am changing it to 100 or 300 but it's not reflecting.
Here is my code
Component.js
return (
<Typography variant="h3" color="secondary">
Arc Development
</Typography>
)
theme.js
import {createMuiTheme} from "#material-ui/core";
const arcBlue = "#0B72B9";
const arcOrange = "#FFBA60";
export default createMuiTheme({
palette: {
common: {
blue: `${arcBlue}`,
orange: `${arcOrange}`,
},
primary: {
main: `${arcBlue}`
},
secondary: {
main: `${arcOrange}`
}
},
typography: {
h3: {
fontS: 0,
}
}
});

Answer 1

Ciao, to override Typography you have to define in your theme an object called overrides and then inside this object you have to define another object called MuiTypography and override the h3 variant like this:
export default createMuiTheme({
palette: {
common: {
blue: `${arcBlue}`,
orange: `${arcOrange}`,
},
primary: {
main: `${arcBlue}`
},
secondary: {
main: `${arcOrange}`
}
},
overrides: {
MuiTypography: {
h3: {
fontWeight: 100
}
}
}
});
And if you inspect the element, you will see:
Here a codesandbox example.