diff --git a/package.json b/package.json
index 1696333d..9a4c2a83 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,7 @@
     "@modelcontextprotocol/ext-apps": "^1.7.2",
     "@modelcontextprotocol/sdk": "^1.29.0",
     "@opencode-ai/sdk": "^1.17.13",
-    "@pierre/diffs": "^1.2.5",
+    "@pierre/diffs": "^1.3.6",
     "better-result": "^2.10.0",
     "better-sqlite3": "^12.10.0",
     "cross-spawn": "^7.0.6",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 26f7684e..ff4ab0a7 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -33,8 +33,8 @@ importers:
         specifier: ^1.17.13
         version: 1.17.13
       '@pierre/diffs':
-        specifier: ^1.2.5
-        version: 1.2.5(react-dom@19.2.6(react@19.2.6))(react@19.2.6)
+        specifier: ^1.3.6
+        version: 1.3.6(@shikijs/themes@3.23.0)(react-dom@19.2.6(react@19.2.6))(react@19.2.6)
       better-result:
         specifier: ^2.10.0
         version: 2.10.0
@@ -623,16 +623,36 @@ packages:
   '@oxc-project/types@0.133.0':
     resolution: {integrity: sha512-KzkdCd6Uxqnf6l3HOw1xfatAlUURA0g14cvBYFyJ5SaNOQbOUvBr9PKArcPcrNIeRsBdgcUzOGrhKveVpvOIGA==}
 
-  '@pierre/diffs@1.2.5':
-    resolution: {integrity: sha512-uYOz3Kfs5ED0qY0VraUXzylsEKvZPTVdexboM3QKPx/qBZmTT9F3lKAFuPpY5aIrV04sdHtoFCKStyzEu99U2A==}
+  '@pierre/diffs@1.3.6':
+    resolution: {integrity: sha512-a3woaW2QHy78JDxPJK0OJzwZUN4xoQLLIS/pceO8X6+L8gA5D682mP7/w3YxxEVRPXOaoe/p/RJ5Oj/3nrEzew==}
     peerDependencies:
       react: ^18.3.1 || ^19.0.0
       react-dom: ^18.3.1 || ^19.0.0
 
-  '@pierre/theme@1.0.3':
-    resolution: {integrity: sha512-sWHv11TMoqKxKDgTIk5VbhQjdPhs8DCcBxbjh3mRlS3YOM/OcrWoGX6MM8eBGn9cUu3M46Py0JnxsG2nJaFTuA==}
+  '@pierre/theme@2.0.0':
+    resolution: {integrity: sha512-yNDd9GYLQl1mEUJR8AneJ5e4ohLIHQd/wZLWr4fagt78vS2RwwZNW530vVgHqXFAyFVcFlRmGUD5ramXH46OXw==}
     engines: {vscode: ^1.0.0}
 
+  '@pierre/theming@1.0.1':
+    resolution: {integrity: sha512-WCI5Qd7iprDpISL9fBYOLe8RV53+b7mFNA3bPzl60/2CKCSrsKN8zEcep6Y3BAzvARlmca50zGjDodqPGiTUKA==}
+    peerDependencies:
+      '@pierre/theme': ^1.1.0 || ^2.0.0
+      '@shikijs/themes': ^3.0.0 || ^4.0.0
+      react: ^18.3.1 || ^19.0.0
+      react-dom: ^18.3.1 || ^19.0.0
+      shiki: ^3.0.0 || ^4.0.0
+    peerDependenciesMeta:
+      '@pierre/theme':
+        optional: true
+      '@shikijs/themes':
+        optional: true
+      react:
+        optional: true
+      react-dom:
+        optional: true
+      shiki:
+        optional: true
+
   '@pondwader/socks5-server@1.0.10':
     resolution: {integrity: sha512-bQY06wzzR8D2+vVCUoBsr5QS2U6UgPUQRmErNwtsuI6vLcyRKkafjkr3KxbtGFf9aBBIV2mcvlsKD1UYaIV+sg==}
 
@@ -1074,6 +1094,10 @@ packages:
     resolution: {integrity: sha512-DPi0FmjiSU5EvQV0++GFDOJ9ASQUVFh5kD+OzOnYdi7n3Wpm9hWWGfB/O2blfHcMVTL5WkQXSnRiK9makhrcnw==}
     engines: {node: '>=0.3.1'}
 
+  diff@9.0.0:
+    resolution: {integrity: sha512-svtcdpS8CgJyqAjEQIXdb3OjhFVVYjzGAPO8WGCmRbrml64SPw/jJD4GoE98aR7r25A0XcgrK3F02yw9R/vhQw==}
+    engines: {node: '>=0.3.1'}
+
   drizzle-orm@0.45.2:
     resolution: {integrity: sha512-kY0BSaTNYWnoDMVoyY8uxmyHjpJW1geOmBMdSSicKo9CIIWkSxMIj2rkeSR51b8KAPB7m+qysjuHme5nKP+E5Q==}
     peerDependencies:
@@ -2635,18 +2659,29 @@ snapshots:
 
   '@oxc-project/types@0.133.0': {}
 
-  '@pierre/diffs@1.2.5(react-dom@19.2.6(react@19.2.6))(react@19.2.6)':
+  '@pierre/diffs@1.3.6(@shikijs/themes@3.23.0)(react-dom@19.2.6(react@19.2.6))(react@19.2.6)':
     dependencies:
-      '@pierre/theme': 1.0.3
+      '@pierre/theme': 2.0.0
+      '@pierre/theming': 1.0.1(@pierre/theme@2.0.0)(@shikijs/themes@3.23.0)(react-dom@19.2.6(react@19.2.6))(react@19.2.6)(shiki@3.23.0)
       '@shikijs/transformers': 3.23.0
-      diff: 8.0.3
+      diff: 9.0.0
       hast-util-to-html: 9.0.5
       lru_map: 0.4.1
       react: 19.2.6
       react-dom: 19.2.6(react@19.2.6)
       shiki: 3.23.0
+    transitivePeerDependencies:
+      - '@shikijs/themes'
 
-  '@pierre/theme@1.0.3': {}
+  '@pierre/theme@2.0.0': {}
+
+  '@pierre/theming@1.0.1(@pierre/theme@2.0.0)(@shikijs/themes@3.23.0)(react-dom@19.2.6(react@19.2.6))(react@19.2.6)(shiki@3.23.0)':
+    optionalDependencies:
+      '@pierre/theme': 2.0.0
+      '@shikijs/themes': 3.23.0
+      react: 19.2.6
+      react-dom: 19.2.6(react@19.2.6)
+      shiki: 3.23.0
 
   '@pondwader/socks5-server@1.0.10': {}
 
@@ -3035,6 +3070,8 @@ snapshots:
 
   diff@8.0.4: {}
 
+  diff@9.0.0: {}
+
   drizzle-orm@0.45.2(@opentelemetry/api@1.9.0)(@types/better-sqlite3@7.6.13)(better-sqlite3@12.10.0):
     optionalDependencies:
       '@opentelemetry/api': 1.9.0
diff --git a/src/ui/workspace-app.css b/src/ui/workspace-app.css
index 92dc4bf2..08a2ddc9 100644
--- a/src/ui/workspace-app.css
+++ b/src/ui/workspace-app.css
@@ -793,8 +793,12 @@ body {
   --diffs-dark-bg: var(--tool-payload-bg, var(--color-background-primary, #101114));
   --diffs-font-family: var(--font-mono, ui-monospace, SFMono-Regular, monospace);
   --diffs-header-font-family: var(--font-sans, ui-sans-serif, system-ui, sans-serif);
-  --diffs-font-size: var(--font-text-sm-size, 12px);
+  /* Keep iOS WebKit from inflating dense diff text independently of the card UI. */
+  --diffs-font-size: 12px;
   --diffs-line-height: 20px;
+
+  -webkit-text-size-adjust: 100%;
+  text-size-adjust: 100%;
   display: block;
   overflow: visible;
   border-bottom-right-radius: 8px;