diff --git a/package-lock.json b/package-lock.json
index 86cb501..7e79b89 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17,7 +17,7 @@
         "eslint-config-it4c": "^0.11.2",
         "http-server": "^14.1.1",
         "sass-embedded": "^1.97.3",
-        "tailwindcss": "^4.1.17",
+        "tailwindcss": "^4.2.1",
         "textlint": "^15.5.1",
         "textlint-filter-rule-comments": "^1.3.0",
         "textlint-rule-apostrophe": "^3.0.0",
@@ -3680,6 +3680,13 @@
         "tailwindcss": "4.2.0"
       }
     },
+    "node_modules/@tailwindcss/node/node_modules/tailwindcss": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.2.0.tgz",
+      "integrity": "sha512-yYzTZ4++b7fNYxFfpnberEEKu43w44aqDMNM9MHMmcKuCH7lL8jJ4yJ7LGHv7rSwiqM0nkiobF9I6cLlpS2P7Q==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@tailwindcss/oxide": {
       "version": "4.2.0",
       "resolved": "https://registry.npmjs.org/@tailwindcss/oxide/-/oxide-4.2.0.tgz",
@@ -4000,6 +4007,13 @@
         "vite": "^5.2.0 || ^6 || ^7"
       }
     },
+    "node_modules/@tailwindcss/vite/node_modules/tailwindcss": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.2.0.tgz",
+      "integrity": "sha512-yYzTZ4++b7fNYxFfpnberEEKu43w44aqDMNM9MHMmcKuCH7lL8jJ4yJ7LGHv7rSwiqM0nkiobF9I6cLlpS2P7Q==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@textlint-rule/textlint-rule-no-unmatched-pair": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/@textlint-rule/textlint-rule-no-unmatched-pair/-/textlint-rule-no-unmatched-pair-2.0.4.tgz",
@@ -20209,9 +20223,9 @@
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.2.0",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.2.0.tgz",
-      "integrity": "sha512-yYzTZ4++b7fNYxFfpnberEEKu43w44aqDMNM9MHMmcKuCH7lL8jJ4yJ7LGHv7rSwiqM0nkiobF9I6cLlpS2P7Q==",
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.2.1.tgz",
+      "integrity": "sha512-/tBrSQ36vCleJkAOsy9kbNTgaxvGbyOamC30PRePTQe/o1MFwEKHQk4Cn7BNGaPtjp+PuUrByJehM1hgxfq4sw==",
       "dev": true,
       "license": "MIT"
     },
diff --git a/package.json b/package.json
index 0ebaf6c..64e743d 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "eslint-config-it4c": "^0.11.2",
     "http-server": "^14.1.1",
     "sass-embedded": "^1.97.3",
-    "tailwindcss": "^4.1.17",
+    "tailwindcss": "^4.2.1",
     "textlint": "^15.5.1",
     "textlint-filter-rule-comments": "^1.3.0",
     "textlint-rule-apostrophe": "^3.0.0",