Using SCSS.

assets/style.scss

@@ -9,8 +9,7 @@
 
 .peertube-plugin-livechat-buttons {
   display: flex;
-  flex-direction: row;
-  flex-wrap: wrap;
+  flex-flow: row wrap;
   justify-content: flex-end;
 }
 
@@ -72,7 +71,7 @@
 
 table.peertube-plugin-livechat-prosody-list-rooms {
   border: 1px solid black;
-  margin: 5px 0px;
+  margin: 5px 0;
 }
 
 table.peertube-plugin-livechat-prosody-list-rooms tr:nth-child(odd) {

package-lock.json

@@ -764,7 +764,6 @@
       "resolved": "https://registry.npmjs.org/anymatch/-/anymatch-3.1.2.tgz",
       "integrity": "sha512-P43ePfOAIupkguHUycrc4qJ9kz8ZiuOUijaETwX7THt0Y/GNK7v0aa8rY816xWjZ7rJdA5XdMcpVFTKMq+RvWg==",
       "dev": true,
-      "optional": true,
       "requires": {
         "normalize-path": "^3.0.0",
         "picomatch": "^2.0.4"
@@ -1161,8 +1160,7 @@
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/binary-extensions/-/binary-extensions-2.2.0.tgz",
       "integrity": "sha512-jDctJ/IVQbZoJykoeHbhXpOlNBqGNcwXJKJog42E5HDPUwQTSdjCHdihjj0DlnheQ7blbT6dHOafNAiS8ooQKA==",
-      "dev": true,
-      "optional": true
+      "dev": true
     },
     "bluebird": {
       "version": "3.7.2",
@@ -1548,7 +1546,6 @@
       "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-3.5.2.tgz",
       "integrity": "sha512-ekGhOnNVPgT77r4K/U3GDhu+FQ2S8TnK/s2KbIGXi0SZWuwkZ2QNyfWdZW+TVfn84DpEP7rLeCt2UI6bJ8GwbQ==",
       "dev": true,
-      "optional": true,
       "requires": {
         "anymatch": "~3.1.2",
         "braces": "~3.0.2",
@@ -3908,7 +3905,6 @@
       "resolved": "https://registry.npmjs.org/is-binary-path/-/is-binary-path-2.1.0.tgz",
       "integrity": "sha512-ZMERYes6pDydyuGidse7OsHxtbI7WVeUEozgR/g7rd0xUimYNlvZRE/K2MgZTjWy725IfelLeVcEM97mmtRGXw==",
       "dev": true,
-      "optional": true,
       "requires": {
         "binary-extensions": "^2.0.0"
       }
@@ -5548,7 +5544,6 @@
       "resolved": "https://registry.npmjs.org/readdirp/-/readdirp-3.6.0.tgz",
       "integrity": "sha512-hOS089on8RduqdbhvQ5Z37A0ESjsqz6qnRcffsMU3495FuTdqSm+7bhJ29JvIOsBDEEnan5DPu9t3To9VRlMzA==",
       "dev": true,
-      "optional": true,
       "requires": {
         "picomatch": "^2.2.1"
       }
@@ -5760,6 +5755,15 @@
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
       "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
     },
+    "sass": {
+      "version": "1.43.4",
+      "resolved": "https://registry.npmjs.org/sass/-/sass-1.43.4.tgz",
+      "integrity": "sha512-/ptG7KE9lxpGSYiXn7Ar+lKOv37xfWsZRtFYal2QHNigyVQDx685VFT/h7ejVr+R8w7H4tmUgtulsKl5YpveOg==",
+      "dev": true,
+      "requires": {
+        "chokidar": ">=3.0.0 <4.0.0"
+      }
+    },
     "schema-utils": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/schema-utils/-/schema-utils-1.0.0.tgz",

package.json

@@ -28,7 +28,7 @@
     }
   ],
   "css": [
-    "assets/style.css"
+    "dist/assets/style.css"
   ],
   "dependencies": {
     "async": "^3.2.2",
@@ -57,6 +57,7 @@
     "eslint-plugin-promise": "^5.1.1",
     "eslint-plugin-standard": "^5.0.0",
     "npm-run-all": "^4.1.5",
+    "sass": "^1.43.4",
     "stylelint": "^14.0.1",
     "stylelint-config-recommended-scss": "^5.0.1",
     "stylelint-config-standard-scss": "^2.0.1",
@@ -86,10 +87,11 @@
     "build:server": "npx tsc --build server/tsconfig.json",
     "build:serverconverse": "mkdir -p dist/server/conversejs && cp conversejs/index.html dist/server/conversejs/",
     "build:prosodymodules": "mkdir -p dist/server/prosody-modules && cp -r prosody-modules/* dist/server/prosody-modules/",
-    "build": "npm-run-all -s clean:light -p build:converse build:images build:webpack build:server build:serverconverse build:prosodymodules",
+    "build:styles": "sass assets:dist/assets",
+    "build": "npm-run-all -s clean:light -p build:converse build:images build:webpack build:server build:serverconverse build:prosodymodules build:styles",
     "lint": "npm-run-all -s lint:script lint:styles",
     "lint:script": "npx eslint --ext .js --ext .ts .",
-    "lint:styles": "stylelint 'conversejs/**/*.scss'",
+    "lint:styles": "stylelint 'conversejs/**/*.scss' 'assets/**/*.css'",
     "show:npmfiles": "npx npm-packlist"
   },
   "staticDirs": {