module.exports = { use: [ 'postcss-flexbugs-fixes', 'autoprefixer' ], map: { inline: false, annotation: true, sourcesContent: true }, autoprefixer: { browsers: [ // // Official browser support policy: // https://v4-alpha.getbootstrap.com/getting-started/browsers-devices/#supported-browsers // 'Chrome >= 35', // Exact version number here is kinda arbitrary // Rather than using Autoprefixer's native "Firefox ESR" version specifier string, // we deliberately hardcode the number. This is to avoid unwittingly severely breaking the previous ESR in the event that: // (a) we happen to ship a new Bootstrap release soon after the release of a new ESR, // such that folks haven't yet had a reasonable amount of time to upgrade; and // (b) the new ESR has unprefixed CSS properties/values whose absence would severely break webpages // (e.g. `box-sizing`, as opposed to `background: linear-gradient(...)`). // Since they've been unprefixed, Autoprefixer will stop prefixing them, // thus causing them to not work in the previous ESR (where the prefixes were required). 'Firefox >= 38', // Current Firefox Extended Support Release (ESR); https://www.mozilla.org/en-US/firefox/organizations/faq/ // Note: Edge versions in Autoprefixer & Can I Use refer to the EdgeHTML rendering engine version, // NOT the Edge app version shown in Edge's "About" screen. // For example, at the time of writing, Edge 20 on an up-to-date system uses EdgeHTML 12. // See also https://github.com/Fyrd/caniuse/issues/1928 'Edge >= 12', 'Explorer >= 10', // Out of leniency, we prefix these 1 version further back than the official policy. 'iOS >= 8', 'Safari >= 8', // The following remain NOT officially supported, but we're lenient and include their prefixes to avoid severely breaking in them. 'Android 2.3', 'Android >= 4', 'Opera >= 12' ] } }