Update

node_modules/glightbox/development/postcss.js

@@ -0,0 +1,63 @@
+const postcss = require('postcss');
+const cssnext = require('postcss-preset-env');
+const cssnested = require('postcss-nested');
+const cssmqpacker = require('css-mqpacker');
+const cssprettify = require('postcss-prettify');
+const cssclean = require('clean-css');
+const path = require('path');
+const fs = require('fs');
+
+function postcssCompiler(config) {
+    const { file, dest, minify = true } = config;
+    const fileName = path.basename(file);
+    const from = path.join(__dirname, '../', file);
+    const to = path.join(__dirname, '../', dest, fileName);
+    const fileNameMin = path.extname(fileName);
+    const min = path.join(__dirname, '../', dest, fileName.replace(fileNameMin, `.min${fileNameMin}`));
+    const css = fs.readFileSync(from, 'utf8');
+
+    return new Promise((resolve, reject) => {
+        return postcss([
+            cssnested(),
+            cssnext({
+                stage: 0,
+                browsers: ['last 2 version'],
+                features: {
+                    calc: false
+                }
+            }),
+            cssmqpacker({
+                sort: true
+            }),
+            cssprettify()
+        ])
+            .process(css, {
+                from,
+                to
+            })
+            .then((result) => {
+                if (result && result.css) {
+                    fs.writeFile(to, result.css, 'utf8', (err) => reject(err));
+
+                    if (minify) {
+                        const minified = new cssclean({}).minify(result.css);
+                        fs.writeFile(min, minified.styles, 'utf8', (err) => reject(err));
+
+                        if (result.map) {
+                            fs.writeFile(to + '.map', result.map, 'utf8', (err) => reject(err));
+                        }
+                    }
+
+                    resolve(to);
+                } else {
+                    reject(result);
+                }
+            })
+            .catch((err) => {
+                console.log(err);
+                reject(err);
+            });
+    });
+}
+
+module.exports = postcssCompiler;