diff --git a/README.md b/README.md
index 6c021c1..19e0642 100644
--- a/README.md
+++ b/README.md
@@ -196,25 +196,25 @@ Brave Search API and YouTube Data API require keys. If omitted, those engines ar
 ## Architecture
 
 ```
-┌─────────────────────────────────────┐
-│           HTTP Handler              │
-│  /search  /  /opensearch.xml       │
-├─────────────────────────────────────┤
-│         Middleware Chain            │
-│  Global → Burst → Per-IP → CORS    │
-├─────────────────────────────────────┤
-│         Search Service              │
-│  Parallel engine execution          │
-│  WaitGroup + graceful degradation   │
-├─────────────────────────────────────┤
-│           Cache Layer               │
-│  Valkey/Redis (optional; no-op if   │
-│  unconfigured)                      │
-├─────────────────────────────────────┤
-│        Engines (×11 default)        │
-│  Each runs in its own goroutine    │
-│  Failures → unresponsive_engines   │
-└─────────────────────────────────────┘
+┌───────────────────────────────────────┐
+│             HTTP Handler              │
+│      /search  /  /opensearch.xml      │
+├───────────────────────────────────────┤
+│            Middleware Chain           │
+│   Global → Burst → Per-IP → CORS      │
+├───────────────────────────────────────┤
+│            Search Service             │
+│     Parallel engine execution         │
+│   WaitGroup + graceful degradation    │
+├───────────────────────────────────────┤
+│             Cache Layer               │
+│  Valkey/Redis (optional; no-op if     │
+│              unconfigured)            │
+├───────────────────────────────────────┤
+│        Engines (×11 default)          │
+│    Each runs in its own goroutine     │
+│   Failures → unresponsive_engines     │
+└───────────────────────────────────────┘
 ```
 
 ## Docker