diff --git a/searx/static/themes/simple/.stylelintrc.json b/searx/static/themes/simple/.stylelintrc.json
index be082eeb4..1e9b64136 100644
--- a/searx/static/themes/simple/.stylelintrc.json
+++ b/searx/static/themes/simple/.stylelintrc.json
@@ -1,7 +1,14 @@
 {
-  "extends": "stylelint-config-standard",
+  "extends": "stylelint-config-standard-less",
   "rules": {
     "declaration-empty-line-before": null,
-    "no-invalid-position-at-import-rule": null
+    "no-invalid-position-at-import-rule": null,
+    "property-no-vendor-prefix": null,
+    "selector-no-vendor-prefix": null,
+    "selector-attribute-quotes": null,
+    "shorthand-property-no-redundant-values": null,
+    "at-rule-no-vendor-prefix": null,
+    "selector-id-pattern": null,
+    "selector-class-pattern": null
   }
 }
diff --git a/searx/static/themes/simple/package-lock.json b/searx/static/themes/simple/package-lock.json
index 072e6a282..6a9f0f22f 100644
--- a/searx/static/themes/simple/package-lock.json
+++ b/searx/static/themes/simple/package-lock.json
@@ -28,6 +28,7 @@
         "sharp": "^0.33.5",
         "stylelint": "^16.12.0",
         "stylelint-config-standard": "^36.0.0",
+        "stylelint-config-standard-less": "^3.0.1",
         "svgo": "^3.3.2"
       }
     },
@@ -7237,6 +7238,19 @@
         "node": "^10 || ^12 || >=14"
       }
     },
+    "node_modules/postcss-less": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/postcss-less/-/postcss-less-6.0.0.tgz",
+      "integrity": "sha512-FPX16mQLyEjLzEuuJtxA8X3ejDLNGGEG503d2YGZR5Ask1SpDN8KmZUMpzCvyalWRywAn1n1VOA5dcqfCLo5rg==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      },
+      "peerDependencies": {
+        "postcss": "^8.3.5"
+      }
+    },
     "node_modules/postcss-resolve-nested-selector": {
       "version": "0.1.6",
       "resolved": "https://registry.npmjs.org/postcss-resolve-nested-selector/-/postcss-resolve-nested-selector-0.1.6.tgz",
@@ -8666,6 +8680,27 @@
         "stylelint": "^16.1.0"
       }
     },
+    "node_modules/stylelint-config-recommended-less": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/stylelint-config-recommended-less/-/stylelint-config-recommended-less-3.0.1.tgz",
+      "integrity": "sha512-4vp9Z+W0KwxgPL4L3WxXtlMurfen0NXKFFxPHzDYn2s6WVS26Gg7jt3FIO4ZLM1x8WalCR02nwK2h0TH/mafBg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "postcss-less": "^6.0.0",
+        "stylelint-config-recommended": "^14.0.0",
+        "stylelint-less": "^3.0.1"
+      },
+      "peerDependencies": {
+        "postcss": "^8.3.3",
+        "stylelint": "^16.0.2"
+      },
+      "peerDependenciesMeta": {
+        "postcss": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/stylelint-config-standard": {
       "version": "36.0.1",
       "resolved": "https://registry.npmjs.org/stylelint-config-standard/-/stylelint-config-standard-36.0.1.tgz",
@@ -8692,6 +8727,57 @@
         "stylelint": "^16.1.0"
       }
     },
+    "node_modules/stylelint-config-standard-less": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/stylelint-config-standard-less/-/stylelint-config-standard-less-3.0.1.tgz",
+      "integrity": "sha512-l6UrXbfy37hWbeOCYrJqnKzhiy5+rkxHNGNufvyhH2K1KpEWO+lO8YrLzoOTx0VyGMatPQlpR8EXrnLRcEcvhg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "stylelint-config-recommended-less": "^3.0.1",
+        "stylelint-config-standard": "^35.0.0"
+      },
+      "peerDependencies": {
+        "postcss": "^8.3.3",
+        "stylelint": "^16.0.2"
+      },
+      "peerDependenciesMeta": {
+        "postcss": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/stylelint-config-standard-less/node_modules/stylelint-config-standard": {
+      "version": "35.0.0",
+      "resolved": "https://registry.npmjs.org/stylelint-config-standard/-/stylelint-config-standard-35.0.0.tgz",
+      "integrity": "sha512-JyQrNZk2BZwVKFauGGxW2U6RuhIfQ4XoHHo+rBzMHcAkLnwI/knpszwXjzxiMgSfcxbZBckM7Vq4LHoANTR85g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "stylelint-config-recommended": "^14.0.0"
+      },
+      "engines": {
+        "node": ">=18.12.0"
+      },
+      "peerDependencies": {
+        "stylelint": "^16.0.0"
+      }
+    },
+    "node_modules/stylelint-less": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/stylelint-less/-/stylelint-less-3.0.1.tgz",
+      "integrity": "sha512-6GkZ4jhmReXxX61IiNaniZFuyTzYTTC4HvRLNNok883d1ux/wUodM1uik+iAHZM1VSCwNASaj0Th6ZX46WZLMw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "postcss-resolve-nested-selector": "^0.1.1",
+        "postcss-value-parser": "4.2.0"
+      },
+      "peerDependencies": {
+        "postcss": "^8.4.31",
+        "stylelint": "^16.0.2"
+      }
+    },
     "node_modules/stylelint/node_modules/balanced-match": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-2.0.0.tgz",
diff --git a/searx/static/themes/simple/package.json b/searx/static/themes/simple/package.json
index 9df658bbf..5ff49057a 100644
--- a/searx/static/themes/simple/package.json
+++ b/searx/static/themes/simple/package.json
@@ -1,23 +1,24 @@
 {
   "devDependencies": {
+    "ejs": "^3.1.10",
     "eslint": "^9.17.0",
     "grunt": "^1.6.1",
     "grunt-contrib-copy": "^1.0.0",
     "grunt-contrib-cssmin": "^5.0.0",
     "grunt-contrib-less": "^3.0.0",
     "grunt-contrib-uglify": "^5.2.2",
-    "grunt-xmlmin": "^0.1.8",
     "grunt-contrib-watch": "^1.1.0",
     "grunt-eslint": "^25.0.0",
-    "grunt-stylelint": "^0.20.1",
     "grunt-image": "^6.4.0",
+    "grunt-stylelint": "^0.20.1",
+    "grunt-xmlmin": "^0.1.8",
     "ionicons": "^7.4.0",
     "less": "^4.2.1",
     "less-plugin-clean-css": "^1.6.0",
     "sharp": "^0.33.5",
     "stylelint": "^16.12.0",
     "stylelint-config-standard": "^36.0.0",
-    "ejs": "^3.1.10",
+    "stylelint-config-standard-less": "^3.0.1",
     "svgo": "^3.3.2"
   },
   "dependencies": {