diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 2da4be3..5ebf7f0 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -46,5 +46,5 @@ repos:
         name: terraform-docs (README.md)
         args: ["--output-mode", "inject", "--output-file", "README.md", "."]
       - id: terraform-docs-go
-        name: terraform-docs (docs/REFERENCE.md)
-        args: ["-c", ".terraform-docs-reference.yml", "--output-mode", "replace", "--output-file", "docs/REFERENCE.md", "."]
+        name: terraform-docs (docs/reference.md)
+        args: ["-c", ".terraform-docs-reference.yml", "--output-mode", "replace", "--output-file", "docs/reference.md", "."]
diff --git a/README.md b/README.md
index 694a9fc..9e9754b 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,7 @@ The event is just a trigger — the reconciler always computes the correct actio
 
 Each NAT uses two persistent ENIs (public + private) created by Terraform. They survive stop/start cycles, keeping route tables intact.
 
-See [Architecture](docs/ARCHITECTURE.md) for the full reconciliation model and event flow diagrams.
+See [Architecture](docs/architecture.md) for the full reconciliation model and event flow diagrams.
 
 ## Quick start
 
@@ -80,7 +80,7 @@ module "nat_zero" {
 }
 ```
 
-See [Examples](docs/EXAMPLES.md) for spot instances, custom AMIs, and building from source.
+See [Examples](docs/examples.md) for spot instances, custom AMIs, and building from source.
 
 ## Performance
 
@@ -92,7 +92,7 @@ See [Examples](docs/EXAMPLES.md) for spot instances, custom AMIs, and building f
 
 The Lambda is a compiled Go ARM64 binary. Cold start: 55 ms. Typical invocation: 400-600 ms. Peak memory: 29 MB. The startup delay is dominated by EC2 instance boot, not the Lambda.
 
-See [Performance](docs/PERFORMANCE.md) for detailed timings and cost breakdowns.
+See [Performance](docs/performance.md) for detailed timings and cost breakdowns.
 
 ## Notes
 
diff --git a/docs/INDEX.md b/docs/INDEX.md
index 4dc0102..fdd5f02 100644
--- a/docs/INDEX.md
+++ b/docs/INDEX.md
@@ -32,8 +32,8 @@ module "nat_zero" {
 
 ## Learn more
 
-- [Architecture](ARCHITECTURE.md) — reconciliation model, decision matrix, event flows
-- [Performance](PERFORMANCE.md) — startup latency, Lambda execution times, cost breakdowns
-- [Examples](EXAMPLES.md) — spot instances, custom AMIs, building from source
-- [Terraform Reference](REFERENCE.md) — inputs, outputs, resources
-- [Testing](TESTING.md) — integration test lifecycle and CI
+- [Architecture](architecture.md) — reconciliation model, decision matrix, event flows
+- [Performance](performance.md) — startup latency, Lambda execution times, cost breakdowns
+- [Examples](examples.md) — spot instances, custom AMIs, building from source
+- [Terraform Reference](reference.md) — inputs, outputs, resources
+- [Testing](testing.md) — integration test lifecycle and CI
diff --git a/docs/ARCHITECTURE.md b/docs/architecture.md
similarity index 100%
rename from docs/ARCHITECTURE.md
rename to docs/architecture.md
diff --git a/docs/EXAMPLES.md b/docs/examples.md
similarity index 100%
rename from docs/EXAMPLES.md
rename to docs/examples.md
diff --git a/docs/PERFORMANCE.md b/docs/performance.md
similarity index 100%
rename from docs/PERFORMANCE.md
rename to docs/performance.md
diff --git a/docs/REFERENCE.md b/docs/reference.md
similarity index 100%
rename from docs/REFERENCE.md
rename to docs/reference.md
diff --git a/docs/SECURITY.md b/docs/security.md
similarity index 100%
rename from docs/SECURITY.md
rename to docs/security.md
diff --git a/docs/TESTING.md b/docs/testing.md
similarity index 100%
rename from docs/TESTING.md
rename to docs/testing.md
diff --git a/docs/WORKFLOWS.md b/docs/workflows.md
similarity index 100%
rename from docs/WORKFLOWS.md
rename to docs/workflows.md
diff --git a/mkdocs.yml b/mkdocs.yml
index 7947405..8ad04ca 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -6,9 +6,9 @@ theme:
   palette:
     scheme: default
 nav:
-  - Home: INDEX.md
-  - Architecture: ARCHITECTURE.md
-  - Performance: PERFORMANCE.md
-  - Examples: EXAMPLES.md
-  - Terraform Reference: REFERENCE.md
-  - Testing: TESTING.md
+  - Home: index.md
+  - Architecture: architecture.md
+  - Performance: performance.md
+  - Examples: examples.md
+  - Terraform Reference: reference.md
+  - Testing: testing.md