Setting --app-shell-border-color

[pale void]

I haven't really understood how to overwrite some of the theme values. If I want to change my colors for
--app-shell-border-color
With different colors depending on light/dark mode. How can I overwrite still value?

[grim sage]

Try to add global css like

:root {
  --app-shell-border-color: var(--mantine-color-gray-3);
}

:root[data-mantine-color-scheme='dark'] {
  --app-shell-border-color: var(--mantine-color-dark-8);
}

You can also use some helpers with PostCSS preset https://mantine.dev/styles/postcss-preset/#light-dark-function