recently, when upgrading the vue-cli3.0 package, I found that css has many more files than before. After looking closely, I found that each .vue file has been packaged with a css, and as long as there is a style tag in the .vue file, even if there is no css, it will be packaged with an empty css, a css after the previous package
. 
here is my profile vue.config.js
module.exports = {
pages: {
index: {
// js
entry: "./src/main.js",
//
template: "./public/index.html"
},
test: {
// js
entry: "./src/test/main.js",
//
template: "./public/test.html"
}
},
// css: {
// // extract: false
// },
devServer: {
// port: 9526, //
// host: "localhost",
https: false, // https:{type:Boolean}
open: true, //
// proxy: "http://localhost:4000" // ,
proxy: {
"/api": {
target: " http://192.168.10.44:7300/mock/5b7172e53e69ed21b4690861/api",
changeOrigin: true,
pathRewrite: {
"^/api": "" // rewrite,
}
}
} //
}
}