diff --git a/webui/CHANGELOG.md b/webui/CHANGELOG.md
index ba9d217c1..a39d07208 100644
--- a/webui/CHANGELOG.md
+++ b/webui/CHANGELOG.md
@@ -6,6 +6,7 @@ This change log covers only the frontend library (webui) of Open VSX.
 
 ### Fixed
 
+- Fix the WebUI build failing on s390x and ppc64le: use postcss instead of lightningcss (no ppc64le binary) for CSS, and bump vite for the Rolldown big-endian sourcemap fix ([#2051](https://github.com/eclipse-openvsx/openvsx/issues/2051))
 - Fix the admin publisher revoke dialog prompting for an Eclipse login even when the target publisher's agreement status is `none` or could not be determined (nothing confirmed to revoke)
 
 ### Dependencies
@@ -13,6 +14,7 @@ This change log covers only the frontend library (webui) of Open VSX.
 - Bump socks from `2.8.3` to `2.8.9`
 - Bump ip-address from `9.0.5` to `10.4.0`
 - Bump postcss from `8.5.22` to `8.5.25`
+- Bump vite from `8.1.5` to `8.2.1`
 
 ## [v1.1.0] (02/08/2026)
 
diff --git a/webui/package.json b/webui/package.json
index 8a87fbc5e..8947cc847 100644
--- a/webui/package.json
+++ b/webui/package.json
@@ -116,7 +116,7 @@
         "rollup-plugin-visualizer": "^7.0.1",
         "ts-node": "^10.9.2",
         "typescript": "^5.9.0",
-        "vite": "^8.1.5",
+        "vite": "^8.2.1",
         "vitest": "^4.1.10"
     },
     "scripts": {
diff --git a/webui/vite.config.mts b/webui/vite.config.mts
index bbedb9a8a..35c34f51b 100644
--- a/webui/vite.config.mts
+++ b/webui/vite.config.mts
@@ -4,7 +4,7 @@ import react from '@vitejs/plugin-react';
 import { defineConfig, PluginOption } from 'vite';
 import { visualizer } from 'rollup-plugin-visualizer';
 
-const outRootDir = path.join(__dirname, 'dist');
+const outRootDir = path.join(import.meta.dirname, 'dist');
 
 export default defineConfig(() => ({
     plugins: [react(), visualizer() as PluginOption],
@@ -17,7 +17,7 @@ export default defineConfig(() => ({
     },
     resolve: {
         alias: {
-            '@': path.resolve(__dirname, './src')
+            '@': path.resolve(import.meta.dirname, './src')
         }
     },
     publicDir: 'static',
@@ -26,9 +26,16 @@ export default defineConfig(() => ({
         environment: 'jsdom',
         setupFiles: ['./test/setup.ts']
     },
+    // lightningcss (Vite 8's default CSS transformer) ships no prebuilt binary for ppc64le,
+    // and its minifier isn't needed once postcss is handling transforms - see
+    // https://github.com/eclipse-openvsx/openvsx/issues/2051
+    css: {
+        transformer: 'postcss'
+    },
     build: {
         target: 'es2020',
         minify: true,
+        cssMinify: false,
         sourcemap: true,
         outDir: outRootDir,
         emptyOutDir: true,
diff --git a/webui/yarn.lock b/webui/yarn.lock
index ff119bc13..7256c0b16 100644
--- a/webui/yarn.lock
+++ b/webui/yarn.lock
@@ -1103,6 +1103,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@oxc-project/types@npm:=0.143.0":
+  version: 0.143.0
+  resolution: "@oxc-project/types@npm:0.143.0"
+  checksum: 10/27a70f58e15ea5619b94f1be01a0e3d8cdc41442826f3d08cf6eb55e4c24d3d753cef2a68ae9d298eb55b5f1405145af6b1eacf8cbd4834151b9e3e1206f3401
+  languageName: node
+  linkType: hard
+
 "@pkgr/core@npm:^0.3.6":
   version: 0.3.6
   resolution: "@pkgr/core@npm:0.3.6"
@@ -1135,6 +1142,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-android-arm64@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-android-arm64@npm:1.2.3"
+  conditions: os=android & cpu=arm64
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-darwin-arm64@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-darwin-arm64@npm:1.1.5"
@@ -1142,6 +1156,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-darwin-arm64@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-darwin-arm64@npm:1.2.3"
+  conditions: os=darwin & cpu=arm64
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-darwin-x64@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-darwin-x64@npm:1.1.5"
@@ -1149,6 +1170,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-darwin-x64@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-darwin-x64@npm:1.2.3"
+  conditions: os=darwin & cpu=x64
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-freebsd-x64@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-freebsd-x64@npm:1.1.5"
@@ -1156,6 +1184,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-freebsd-x64@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-freebsd-x64@npm:1.2.3"
+  conditions: os=freebsd & cpu=x64
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-arm-gnueabihf@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-arm-gnueabihf@npm:1.1.5"
@@ -1163,6 +1198,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-arm-gnueabihf@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-arm-gnueabihf@npm:1.2.3"
+  conditions: os=linux & cpu=arm
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-arm64-gnu@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-arm64-gnu@npm:1.1.5"
@@ -1170,6 +1212,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-arm64-gnu@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-arm64-gnu@npm:1.2.3"
+  conditions: os=linux & cpu=arm64 & libc=glibc
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-arm64-musl@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-arm64-musl@npm:1.1.5"
@@ -1177,6 +1226,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-arm64-musl@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-arm64-musl@npm:1.2.3"
+  conditions: os=linux & cpu=arm64 & libc=musl
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-ppc64-gnu@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-ppc64-gnu@npm:1.1.5"
@@ -1184,6 +1240,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-ppc64-gnu@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-ppc64-gnu@npm:1.2.3"
+  conditions: os=linux & cpu=ppc64 & libc=glibc
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-s390x-gnu@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-s390x-gnu@npm:1.1.5"
@@ -1191,6 +1254,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-s390x-gnu@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-s390x-gnu@npm:1.2.3"
+  conditions: os=linux & cpu=s390x & libc=glibc
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-x64-gnu@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-x64-gnu@npm:1.1.5"
@@ -1198,6 +1268,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-x64-gnu@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-x64-gnu@npm:1.2.3"
+  conditions: os=linux & cpu=x64 & libc=glibc
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-linux-x64-musl@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-linux-x64-musl@npm:1.1.5"
@@ -1205,6 +1282,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-linux-x64-musl@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-linux-x64-musl@npm:1.2.3"
+  conditions: os=linux & cpu=x64 & libc=musl
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-openharmony-arm64@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-openharmony-arm64@npm:1.1.5"
@@ -1212,6 +1296,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-openharmony-arm64@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-openharmony-arm64@npm:1.2.3"
+  conditions: os=openharmony & cpu=arm64
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-wasm32-wasi@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-wasm32-wasi@npm:1.1.5"
@@ -1230,6 +1321,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-win32-arm64-msvc@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-win32-arm64-msvc@npm:1.2.3"
+  conditions: os=win32 & cpu=arm64
+  languageName: node
+  linkType: hard
+
 "@rolldown/binding-win32-x64-msvc@npm:1.1.5":
   version: 1.1.5
   resolution: "@rolldown/binding-win32-x64-msvc@npm:1.1.5"
@@ -1237,6 +1335,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rolldown/binding-win32-x64-msvc@npm:1.2.3":
+  version: 1.2.3
+  resolution: "@rolldown/binding-win32-x64-msvc@npm:1.2.3"
+  conditions: os=win32 & cpu=x64
+  languageName: node
+  linkType: hard
+
 "@rolldown/pluginutils@npm:^1.0.0, @rolldown/pluginutils@npm:^1.0.1":
   version: 1.0.1
   resolution: "@rolldown/pluginutils@npm:1.0.1"
@@ -5048,7 +5153,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"lightningcss@npm:^1.32.0":
+"lightningcss@npm:^1.32.0, lightningcss@npm:^1.33.0":
   version: 1.33.0
   resolution: "lightningcss@npm:1.33.0"
   dependencies:
@@ -5453,6 +5558,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"nanoid@npm:^3.3.17":
+  version: 3.3.18
+  resolution: "nanoid@npm:3.3.18"
+  bin:
+    nanoid: bin/nanoid.cjs
+  checksum: 10/1b3b4fdac831b92b56d1dbe8b1e63a372432faf86ea383134e3b53141ef8108a60b7f84343b5cefecac9550bb74edf8164da93ea07d1c4f757039bc75d8a5d9e
+  languageName: node
+  linkType: hard
+
 "natural-compare@npm:^1.4.0":
   version: 1.4.0
   resolution: "natural-compare@npm:1.4.0"
@@ -5718,7 +5832,7 @@ __metadata:
     rollup-plugin-visualizer: "npm:^7.0.1"
     ts-node: "npm:^10.9.2"
     typescript: "npm:^5.9.0"
-    vite: "npm:^8.1.5"
+    vite: "npm:^8.2.1"
     vitest: "npm:^4.1.10"
   languageName: unknown
   linkType: soft
@@ -5949,6 +6063,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"postcss@npm:^8.5.25":
+  version: 8.5.26
+  resolution: "postcss@npm:8.5.26"
+  dependencies:
+    nanoid: "npm:^3.3.17"
+    picocolors: "npm:^1.1.1"
+    source-map-js: "npm:^1.2.1"
+  checksum: 10/842a624f822f77cb37264cc24f0cf97c0a69dd8d6f7b4a6d76b5a8dc95355899dd044f33a2d4e890da858293de570fce18dff453f3b629ff14cac67a3591895a
+  languageName: node
+  linkType: hard
+
 "powershell-utils@npm:^0.1.0":
   version: 0.1.0
   resolution: "powershell-utils@npm:0.1.0"
@@ -6427,6 +6552,61 @@ __metadata:
   languageName: node
   linkType: hard
 
+"rolldown@npm:~1.2.1":
+  version: 1.2.3
+  resolution: "rolldown@npm:1.2.3"
+  dependencies:
+    "@oxc-project/types": "npm:=0.143.0"
+    "@rolldown/binding-android-arm64": "npm:1.2.3"
+    "@rolldown/binding-darwin-arm64": "npm:1.2.3"
+    "@rolldown/binding-darwin-x64": "npm:1.2.3"
+    "@rolldown/binding-freebsd-x64": "npm:1.2.3"
+    "@rolldown/binding-linux-arm-gnueabihf": "npm:1.2.3"
+    "@rolldown/binding-linux-arm64-gnu": "npm:1.2.3"
+    "@rolldown/binding-linux-arm64-musl": "npm:1.2.3"
+    "@rolldown/binding-linux-ppc64-gnu": "npm:1.2.3"
+    "@rolldown/binding-linux-s390x-gnu": "npm:1.2.3"
+    "@rolldown/binding-linux-x64-gnu": "npm:1.2.3"
+    "@rolldown/binding-linux-x64-musl": "npm:1.2.3"
+    "@rolldown/binding-openharmony-arm64": "npm:1.2.3"
+    "@rolldown/binding-win32-arm64-msvc": "npm:1.2.3"
+    "@rolldown/binding-win32-x64-msvc": "npm:1.2.3"
+    "@rolldown/pluginutils": "npm:^1.0.0"
+  dependenciesMeta:
+    "@rolldown/binding-android-arm64":
+      optional: true
+    "@rolldown/binding-darwin-arm64":
+      optional: true
+    "@rolldown/binding-darwin-x64":
+      optional: true
+    "@rolldown/binding-freebsd-x64":
+      optional: true
+    "@rolldown/binding-linux-arm-gnueabihf":
+      optional: true
+    "@rolldown/binding-linux-arm64-gnu":
+      optional: true
+    "@rolldown/binding-linux-arm64-musl":
+      optional: true
+    "@rolldown/binding-linux-ppc64-gnu":
+      optional: true
+    "@rolldown/binding-linux-s390x-gnu":
+      optional: true
+    "@rolldown/binding-linux-x64-gnu":
+      optional: true
+    "@rolldown/binding-linux-x64-musl":
+      optional: true
+    "@rolldown/binding-openharmony-arm64":
+      optional: true
+    "@rolldown/binding-win32-arm64-msvc":
+      optional: true
+    "@rolldown/binding-win32-x64-msvc":
+      optional: true
+  bin:
+    rolldown: ./bin/cli.mjs
+  checksum: 10/553fae06b40d5df3679685807971525b5b5b5fc4e0b5bc661d4cc4214aa6f316b460c6cb296d0352db75287f1fc38cfad1505e54920714e94ac837d1f6e8eceb
+  languageName: node
+  linkType: hard
+
 "rollup-plugin-visualizer@npm:^7.0.1":
   version: 7.0.1
   resolution: "rollup-plugin-visualizer@npm:7.0.1"
@@ -7438,7 +7618,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"vite@npm:^6.0.0 || ^7.0.0 || ^8.0.0, vite@npm:^8.1.5":
+"vite@npm:^6.0.0 || ^7.0.0 || ^8.0.0":
   version: 8.1.5
   resolution: "vite@npm:8.1.5"
   dependencies:
@@ -7495,6 +7675,63 @@ __metadata:
   languageName: node
   linkType: hard
 
+"vite@npm:^8.2.1":
+  version: 8.2.1
+  resolution: "vite@npm:8.2.1"
+  dependencies:
+    fsevents: "npm:~2.3.3"
+    lightningcss: "npm:^1.33.0"
+    picomatch: "npm:^4.0.5"
+    postcss: "npm:^8.5.25"
+    rolldown: "npm:~1.2.1"
+    tinyglobby: "npm:^0.2.17"
+  peerDependencies:
+    "@types/node": ^20.19.0 || >=22.12.0
+    "@vitejs/devtools": ^0.4.0
+    esbuild: ^0.27.0 || ^0.28.0
+    jiti: ">=1.21.0"
+    less: ^4.0.0
+    sass: ^1.70.0
+    sass-embedded: ^1.70.0
+    stylus: ">=0.54.8"
+    sugarss: ^5.0.0
+    terser: ^5.16.0
+    tsx: ^4.8.1
+    yaml: ^2.4.2
+  dependenciesMeta:
+    fsevents:
+      optional: true
+  peerDependenciesMeta:
+    "@types/node":
+      optional: true
+    "@vitejs/devtools":
+      optional: true
+    esbuild:
+      optional: true
+    jiti:
+      optional: true
+    less:
+      optional: true
+    sass:
+      optional: true
+    sass-embedded:
+      optional: true
+    stylus:
+      optional: true
+    sugarss:
+      optional: true
+    terser:
+      optional: true
+    tsx:
+      optional: true
+    yaml:
+      optional: true
+  bin:
+    vite: bin/vite.js
+  checksum: 10/af65bf23dc346f968b8b2f577da4c5d18a5a21eea2ce699eb0018918151238ed185067de1749408d26ba93c743635c5870602bd77b4b6f2f678d8d685a9635d8
+  languageName: node
+  linkType: hard
+
 "vitest@npm:^4.1.10":
   version: 4.1.10
   resolution: "vitest@npm:4.1.10"