I have a .vscode/settings.json in my workspace:

// (workspace) .vscode/settings.json
{
    "files.associations": {
        "*.css": "postcss",
    },
}

but In my user settings.json, I didn't set the file associations:

// (user) settings.json
{}

Then if I enable the dotenv-vscode extension, it automatically adds file associations including "*.css": "postcss" into my user settings.json:

// (user) settings.json
{
    "files.associations": {
        "*.css": "postcss",   // this should not be auto added here
        ".env*": "dotenv",
    },
}

I have to disable this extension now