diff --git a/debug_fasp/Gemfile b/debug_fasp/Gemfile
index 6483d6e..e0b58c5 100644
--- a/debug_fasp/Gemfile
+++ b/debug_fasp/Gemfile
@@ -15,7 +15,7 @@ gem "turbo-rails"
 # Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev]
 gem "stimulus-rails"
 # Use Tailwind CSS [https://github.com/rails/tailwindcss-rails]
-gem "tailwindcss-rails", "~> 3.3.1"
+gem "tailwindcss-rails", "~> 4.0.0"
 # Build JSON APIs with ease [https://github.com/rails/jbuilder]
 gem "jbuilder"
 
diff --git a/debug_fasp/Gemfile.lock b/debug_fasp/Gemfile.lock
index 2f81170..a34d373 100644
--- a/debug_fasp/Gemfile.lock
+++ b/debug_fasp/Gemfile.lock
@@ -334,15 +334,16 @@ GEM
     stimulus-rails (1.3.4)
       railties (>= 6.0.0)
     stringio (3.1.3)
-    tailwindcss-rails (3.3.1)
+    tailwindcss-rails (4.0.0)
       railties (>= 7.0.0)
-      tailwindcss-ruby (~> 3.0)
-    tailwindcss-ruby (3.4.17)
-    tailwindcss-ruby (3.4.17-aarch64-linux)
-    tailwindcss-ruby (3.4.17-arm-linux)
-    tailwindcss-ruby (3.4.17-arm64-darwin)
-    tailwindcss-ruby (3.4.17-x86_64-darwin)
-    tailwindcss-ruby (3.4.17-x86_64-linux)
+      tailwindcss-ruby (~> 4.0)
+    tailwindcss-ruby (4.0.6)
+    tailwindcss-ruby (4.0.6-aarch64-linux-gnu)
+    tailwindcss-ruby (4.0.6-aarch64-linux-musl)
+    tailwindcss-ruby (4.0.6-arm64-darwin)
+    tailwindcss-ruby (4.0.6-x86_64-darwin)
+    tailwindcss-ruby (4.0.6-x86_64-linux-gnu)
+    tailwindcss-ruby (4.0.6-x86_64-linux-musl)
     thor (1.3.2)
     thruster (0.1.11)
     thruster (0.1.11-aarch64-linux)
@@ -412,7 +413,7 @@ DEPENDENCIES
   solid_queue
   sqlite3 (>= 2.1)
   stimulus-rails
-  tailwindcss-rails (~> 3.3.1)
+  tailwindcss-rails (~> 4.0.0)
   thruster
   turbo-rails
   tzinfo-data