I downloaded the extension in vscode (I’d prefer having it work globally, since I’m mostly working with individual css files), here is my config object in C:UsersusernameAppDataRoamingCodeUsersettings.json

    "css.validate": false,
    "stylelint.enable": true,
    "stylelint.config": {
        "rules": {
            "declaration-block-no-duplicate-properties":true,
            "font-family-no-duplicate-names":true,
            "keyframe-block-no-duplicate-selectors":true,
            "no-duplicate-selectors":true
        }
    },
    "stylelint.snippet": [
        "css"
    ],
    "stylelint.validate": [
        "css"
    ]

and it does nothing (here is the code I used to test it)

.subTitleWrap {
    clear: both;
    clear: left;
    font-size: 14px;
    height: 27px;
}

Is there something I’m missing? Like for example do I need to have npm or something?