diff --git a/.gitignore b/.gitignore
index c68b289bb..98e1418fd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,7 +35,6 @@ MANIFEST
 #  before PyInstaller builds the exe, so as to inject date/other infos into it.
 *.manifest
 *.spec
-
 # Installer logs
 pip-log.txt
 pip-delete-this-directory.txt
@@ -163,3 +162,9 @@ doc/source/examples/gallery-examples/
 doc/source/sg_execution_times.rst
 # rendering of sphinx autoapi examples
 doc/source/examples/api/
+
+
+# node modules and env
+node_modules/
+.nodeenv/
+package-lock.json
\ No newline at end of file
diff --git a/doc/changelog.d/639.maintenance.md b/doc/changelog.d/639.maintenance.md
new file mode 100644
index 000000000..2c722911d
--- /dev/null
+++ b/doc/changelog.d/639.maintenance.md
@@ -0,0 +1 @@
+feat: migrate the builds system to stb
\ No newline at end of file
diff --git a/package.json b/package.json
new file mode 100644
index 000000000..893d26ffb
--- /dev/null
+++ b/package.json
@@ -0,0 +1,12 @@
+{
+    "name": "ansys_sphinx_theme",
+    "repository": "https://github.com/ansys/ansys-sphinx-theme",
+
+    "description": "",
+    "main": "",
+    "scripts": {
+        "build": "echo 'No build step needed' "
+    },
+    "dependencies": {},
+    "devDependencies": {}
+}
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index a48b6cc87..91aba3f76 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,12 @@
 [build-system]
-requires = ["flit_core >=3.2,<4"]
-build-backend = "flit_core.buildapi"
+requires = [
+  "sphinx-theme-builder >= 0.2.0b2,<1",
+]
+build-backend = "sphinx_theme_builder"
+
+[tool.sphinx-theme-builder]
+node-version = "22.14.0"
+theme-name = "ansys_sphinx_theme"
 
 [project]
 # Check https://flit.readthedocs.io/en/latest/pyproject_toml.html for all available sections
@@ -63,19 +69,7 @@ changelog = [
 ]
 
 [project.entry-points."sphinx.html_themes"]
-ansys_sphinx_theme = "ansys_sphinx_theme"
-
-[tool.flit.module]
-name = "ansys_sphinx_theme"
-
-[tool.flit.sdist]
-include = [
-    "src/ansys_sphinx_theme/theme/ansys_sphinx_theme/layout.html",
-    "src/ansys_sphinx_theme/theme/ansys_sphinx_theme/components/breadcrumbs.html",
-    "src/ansys_sphinx_theme/theme/ansys_sphinx_theme/theme.conf",
-    "src/ansys_sphinx_theme/theme/ansys_sphinx_theme/_templates/",
-    "src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/",
-]
+"ansys_sphinx_theme" = "ansys_sphinx_theme"
 
 [project.urls]
 Home = "https://sphinxdocs.ansys.com/"
@@ -147,18 +141,18 @@ name = "Fixed"
 showcontent = true
 
 [[tool.towncrier.type]]
-directory = "dependencies"
-name = "Dependencies"
+directory = "documentation"
+name = "Documentation"
 showcontent = true
 
 [[tool.towncrier.type]]
-directory = "miscellaneous"
-name = "Miscellaneous"
+directory = "test"
+name = "Test"
 showcontent = true
 
 [[tool.towncrier.type]]
-directory = "documentation"
-name = "Documentation"
+directory = "dependencies"
+name = "Dependencies"
 showcontent = true
 
 [[tool.towncrier.type]]
@@ -167,6 +161,6 @@ name = "Maintenance"
 showcontent = true
 
 [[tool.towncrier.type]]
-directory = "test"
-name = "Test"
-showcontent = true
+directory = "miscellaneous"
+name = "Miscellaneous"
+showcontent = true
\ No newline at end of file
diff --git a/src/ansys_sphinx_theme/assets/scripts/.gitkeep b/src/ansys_sphinx_theme/assets/scripts/.gitkeep
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/ansys_sphinx_theme/assets/styles/.gitkeep b/src/ansys_sphinx_theme/assets/styles/.gitkeep
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ansys_sphinx_theme.css b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ansys_sphinx_theme.css
index e11693261..35b38f09c 100644
--- a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ansys_sphinx_theme.css
+++ b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ansys_sphinx_theme.css
@@ -6,6 +6,9 @@
 @import "sphinx-design.css";
 @import "table-custom.css";
 @import "sphinx-gallery.css";
+@import "whatsnew.css";
+@import "nbsphinx.css";
+@import "ansys-sphinx-theme-variable.css";
 
 /*
 * Code cell
diff --git a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ast-search.css b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ast-search.css
index 130272e36..fafdd2bdd 100644
--- a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ast-search.css
+++ b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/ast-search.css
@@ -1,5 +1,3 @@
-@import "ansys-sphinx-theme-variable.css";
-
 .static-search-results {
   display: flex;
   flex-direction: column;
diff --git a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/breadcrumbs.css b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/breadcrumbs.css
index 27e67d65f..75df543d2 100644
--- a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/breadcrumbs.css
+++ b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/breadcrumbs.css
@@ -1,8 +1,5 @@
 /* Provided by the Sphinx base theme template at build time,
 styles exclusively for the ansys-sphinx-theme classes. */
-
-@import "ansys-sphinx-theme-variable.css";
-
 /**
 * Breadcrumbs
 */
diff --git a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/pydata-sphinx-theme-custom.css b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/pydata-sphinx-theme-custom.css
index 1a594ff86..bb840db80 100644
--- a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/pydata-sphinx-theme-custom.css
+++ b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/pydata-sphinx-theme-custom.css
@@ -1,7 +1,5 @@
 /* Changes associated with the Ansys Sphinx Theme */
 /* for pydata-sphinx-theme */
-@import "ansys-sphinx-theme-variable.css";
-
 /*
 *
 * _secondary sidebar and primary sidebars
diff --git a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/sphinx-gallery.css b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/sphinx-gallery.css
index b24541f30..6d6078f30 100644
--- a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/sphinx-gallery.css
+++ b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/static/css/sphinx-gallery.css
@@ -1,5 +1,3 @@
-@import "ansys-sphinx-theme-variable.css";
-
 /**
 * Sphinx gallery output cell
 */
diff --git a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/theme.conf b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/theme.conf
index b25441b24..5d06f558c 100644
--- a/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/theme.conf
+++ b/src/ansys_sphinx_theme/theme/ansys_sphinx_theme/theme.conf
@@ -1,5 +1,6 @@
 [theme]
 inherit = pydata_sphinx_theme
+stylesheet = styles/ansys-sphinx-theme.css
 
 [options]
 contact_mail =