diff --git a/pyproject.toml b/pyproject.toml
index 49dd34f..5023c5b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,7 +42,7 @@ tests = ["pytest==9.0.2", "pytest-xdist==3.8.0"]
 docs = [
   "furo==2025.12.19",
   "packaging==25.0",
-  "sphinx==8.2.3",
+  "sphinx==9.0.4",
   "sphinx-autoapi==3.6.1",
   "sphinx-copybutton==0.5.2",
   "sphinx-lint==1.0.2",
diff --git a/uv.lock b/uv.lock
index 0d4599a..aa2ba49 100644
--- a/uv.lock
+++ b/uv.lock
@@ -403,7 +403,7 @@ dev = [
     { name = "pytest", specifier = "==9.0.2" },
     { name = "pytest-xdist", specifier = "==3.8.0" },
     { name = "ruff", specifier = "==0.14.10" },
-    { name = "sphinx", specifier = "==8.2.3" },
+    { name = "sphinx", specifier = "==9.0.4" },
     { name = "sphinx-autoapi", specifier = "==3.6.1" },
     { name = "sphinx-autobuild", specifier = "==2025.8.25" },
     { name = "sphinx-copybutton", specifier = "==0.5.2" },
@@ -417,7 +417,7 @@ dev = [
 docs = [
     { name = "furo", specifier = "==2025.12.19" },
     { name = "packaging", specifier = "==25.0" },
-    { name = "sphinx", specifier = "==8.2.3" },
+    { name = "sphinx", specifier = "==9.0.4" },
     { name = "sphinx-autoapi", specifier = "==3.6.1" },
     { name = "sphinx-copybutton", specifier = "==0.5.2" },
     { name = "sphinx-lint", specifier = "==1.0.2" },
@@ -435,7 +435,7 @@ gh-actions-check = [
     { name = "pytest", specifier = "==9.0.2" },
     { name = "pytest-xdist", specifier = "==3.8.0" },
     { name = "ruff", specifier = "==0.14.10" },
-    { name = "sphinx", specifier = "==8.2.3" },
+    { name = "sphinx", specifier = "==9.0.4" },
     { name = "sphinx-autoapi", specifier = "==3.6.1" },
     { name = "sphinx-copybutton", specifier = "==0.5.2" },
     { name = "sphinx-lint", specifier = "==1.0.2" },
@@ -449,7 +449,7 @@ misc = [{ name = "taskipy", specifier = "==1.14.1" }]
 readthedocs = [
     { name = "furo", specifier = "==2025.12.19" },
     { name = "packaging", specifier = "==25.0" },
-    { name = "sphinx", specifier = "==8.2.3" },
+    { name = "sphinx", specifier = "==9.0.4" },
     { name = "sphinx-autoapi", specifier = "==3.6.1" },
     { name = "sphinx-copybutton", specifier = "==0.5.2" },
     { name = "sphinx-lint", specifier = "==1.0.2" },
@@ -676,18 +676,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/04/54/6f679c435d28e0a568d8e8a7c0a93a09010818634c3c3907fc98d8983770/roman_numerals-4.1.0-py3-none-any.whl", hash = "sha256:647ba99caddc2cc1e55a51e4360689115551bf4476d90e8162cf8c345fe233c7", size = 7676, upload-time = "2025-12-17T18:25:33.098Z" },
 ]
 
-[[package]]
-name = "roman-numerals-py"
-version = "4.1.0"
-source = { registry = "https://pypi.org/simple" }
-dependencies = [
-    { name = "roman-numerals" },
-]
-sdist = { url = "https://files.pythonhosted.org/packages/cb/b5/de96fca640f4f656eb79bbee0e79aeec52e3e0e359f8a3e6a0d366378b64/roman_numerals_py-4.1.0.tar.gz", hash = "sha256:f5d7b2b4ca52dd855ef7ab8eb3590f428c0b1ea480736ce32b01fef2a5f8daf9", size = 4274, upload-time = "2025-12-17T18:25:41.153Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/27/2c/daca29684cbe9fd4bc711f8246da3c10adca1ccc4d24436b17572eb2590e/roman_numerals_py-4.1.0-py3-none-any.whl", hash = "sha256:553114c1167141c1283a51743759723ecd05604a1b6b507225e91dc1a6df0780", size = 4547, upload-time = "2025-12-17T18:25:40.136Z" },
-]
-
 [[package]]
 name = "ruff"
 version = "0.14.10"
@@ -734,7 +722,7 @@ wheels = [
 
 [[package]]
 name = "sphinx"
-version = "8.2.3"
+version = "9.0.4"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "alabaster" },
@@ -746,7 +734,7 @@ dependencies = [
     { name = "packaging" },
     { name = "pygments" },
     { name = "requests" },
-    { name = "roman-numerals-py" },
+    { name = "roman-numerals" },
     { name = "snowballstemmer" },
     { name = "sphinxcontrib-applehelp" },
     { name = "sphinxcontrib-devhelp" },
@@ -755,9 +743,9 @@ dependencies = [
     { name = "sphinxcontrib-qthelp" },
     { name = "sphinxcontrib-serializinghtml" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/38/ad/4360e50ed56cb483667b8e6dadf2d3fda62359593faabbe749a27c4eaca6/sphinx-8.2.3.tar.gz", hash = "sha256:398ad29dee7f63a75888314e9424d40f52ce5a6a87ae88e7071e80af296ec348", size = 8321876, upload-time = "2025-03-02T22:31:59.658Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/42/50/a8c6ccc36d5eacdfd7913ddccd15a9cee03ecafc5ee2bc40e1f168d85022/sphinx-9.0.4.tar.gz", hash = "sha256:594ef59d042972abbc581d8baa577404abe4e6c3b04ef61bd7fc2acbd51f3fa3", size = 8710502, upload-time = "2025-12-04T07:45:27.343Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/31/53/136e9eca6e0b9dc0e1962e2c908fbea2e5ac000c2a2fbd9a35797958c48b/sphinx-8.2.3-py3-none-any.whl", hash = "sha256:4405915165f13521d875a8c29c8970800a0141c14cc5416a38feca4ea5d9b9c3", size = 3589741, upload-time = "2025-03-02T22:31:56.836Z" },
+    { url = "https://files.pythonhosted.org/packages/c6/3f/4bbd76424c393caead2e1eb89777f575dee5c8653e2d4b6afd7a564f5974/sphinx-9.0.4-py3-none-any.whl", hash = "sha256:5bebc595a5e943ea248b99c13814c1c5e10b3ece718976824ffa7959ff95fffb", size = 3917713, upload-time = "2025-12-04T07:45:24.944Z" },
 ]
 
 [[package]]