diff --git a/media/style.css b/media/style.css
index c01c088..5102a8b 100644
--- a/media/style.css
+++ b/media/style.css
@@ -2323,18 +2323,19 @@ html.pi-viewport-recovering #pi-web-app {
    expected while reading; scrolling past the end chains to the conversation). */
 .thinking-block:not(.thinking-collapsed) .thinking-content {
   display: block;
-  max-height: min(60vh, 520px);
+  max-height: min(60vh, 260px);
   overflow-y: auto;
 }
 
-/* Live (spinner present): bottom-aligned latest lines, capped and clipped
-   without a nested scrollbar so the wheel always scrolls the conversation.
-   Kept last so it wins over the reader rule while the model is thinking. */
+/* Live (spinner present): bottom-aligned latest lines, capped with the same
+   max height as the finished reader and clipped without a nested scrollbar so
+   the wheel always scrolls the conversation. Kept last so it wins over the
+   reader rule while the model is thinking. */
 .thinking-block:has(.thinking-spinner) .thinking-content {
   display: flex;
   flex-direction: column;
   justify-content: flex-end;
-  max-height: 320px;
+  max-height: min(60vh, 260px);
   overflow: hidden;
 }
 
diff --git a/src/test/thinking-height.test.ts b/src/test/thinking-height.test.ts
new file mode 100644
index 0000000..07fb0de
--- /dev/null
+++ b/src/test/thinking-height.test.ts
@@ -0,0 +1,34 @@
+import * as assert from "node:assert";
+import { readFileSync } from "node:fs";
+
+const styles = readFileSync(
+  new URL("../../media/style.css", import.meta.url),
+  "utf8",
+);
+
+suite("Thinking block height", () => {
+  test("halves the finished reader height to 260px", () => {
+    const rule = styles.match(/\.thinking-block:not\(\.thinking-collapsed\) \.thinking-content \{[\s\S]*?\n\}/)?.[0];
+    assert.ok(rule, "finished thinking reader rule not found");
+    assert.match(rule, /max-height: min\(60vh, 260px\)/);
+  });
+
+  test("uses the same max height for the live streaming tail", () => {
+    const reader = styles.match(/\.thinking-block:not\(\.thinking-collapsed\) \.thinking-content \{[\s\S]*?\n\}/)?.[0];
+    const live = styles.match(/\.thinking-block:has\(\.thinking-spinner\) \.thinking-content \{[\s\S]*?\n\}/)?.[0];
+    assert.ok(live, "live thinking rule not found");
+    assert.match(live, /max-height: min\(60vh, 260px\)/);
+    assert.strictEqual(
+      live?.match(/max-height: [^;]+;/)?.[0],
+      reader?.match(/max-height: [^;]+;/)?.[0],
+      "both thinking modes must cap at the same height",
+    );
+  });
+
+  test("keeps per-mode overflow behaviour intact", () => {
+    const reader = styles.match(/\.thinking-block:not\(\.thinking-collapsed\) \.thinking-content \{[\s\S]*?\n\}/)?.[0];
+    const live = styles.match(/\.thinking-block:has\(\.thinking-spinner\) \.thinking-content \{[\s\S]*?\n\}/)?.[0];
+    assert.match(reader ?? "", /overflow-y: auto/);
+    assert.match(live ?? "", /overflow: hidden/);
+  });
+});