newsupernova/vendor/magento/magento2-base/dev/tools/grunt/configs/autoprefixer.json

{
    "options": {
        "browsers": [
            "last 2 versions",
            "ie 11"
        ]
    },
    "setup": {
        "src": "<%= path.css.setup %>/setup.css"
    },
    "updater": {
        "src": "<%= path.css.updater %>/updater.css"
    }
}