diff --git a/cypress/integration/rendering/treemap.spec.ts b/cypress/integration/rendering/treemap.spec.ts
new file mode 100644
index 000000000..ae41ee5ff
--- /dev/null
+++ b/cypress/integration/rendering/treemap.spec.ts
@@ -0,0 +1,193 @@
+import { imgSnapshotTest } from '../../helpers/util.ts';
+
+describe('Treemap Diagram', () => {
+  it('1: should render a basic treemap', () => {
+    imgSnapshotTest(
+      `treemap
+"Category A"
+    "Item A1": 10
+    "Item A2": 20
+"Category B"
+    "Item B1": 15
+    "Item B2": 25
+      `,
+      {}
+    );
+  });
+
+  it('2: should render a hierarchical treemap', () => {
+    imgSnapshotTest(
+      `treemap
+"Products"
+    "Electronics"
+        "Phones": 50
+        "Computers": 30
+        "Accessories": 20
+    "Clothing"
+        "Men's"
+            "Shirts": 10
+            "Pants": 15
+        "Women's"
+            "Dresses": 20
+            "Skirts": 10
+      `,
+      {}
+    );
+  });
+
+  it('3: should render a treemap with styling using classDef', () => {
+    imgSnapshotTest(
+      `treemap
+"Section 1"
+    "Leaf 1.1": 12
+    "Section 1.2":::class1
+      "Leaf 1.2.1": 12
+"Section 2"
+    "Leaf 2.1": 20:::class1
+    "Leaf 2.2": 25
+    "Leaf 2.3": 12
+
+classDef class1 fill:red,color:blue,stroke:#FFD600;
+      `,
+      {}
+    );
+  });
+
+  it('4: should handle long text that wraps', () => {
+    imgSnapshotTest(
+      `treemap
+"Main Category"
+    "This is a very long item name that should wrap to the next line when rendered in the treemap diagram": 50
+    "Short item": 20
+      `,
+      {}
+    );
+  });
+
+  it('5: should render with a forest theme', () => {
+    imgSnapshotTest(
+      `%%{init: {'theme': 'forest'}}%%
+treemap
+"Category A"
+    "Item A1": 10
+    "Item A2": 20
+"Category B"
+    "Item B1": 15
+    "Item B2": 25
+      `,
+      {}
+    );
+  });
+
+  it('6: should handle multiple levels of nesting', () => {
+    imgSnapshotTest(
+      `treemap
+"Level 1"
+    "Level 2A"
+        "Level 3A": 10
+        "Level 3B": 15
+    "Level 2B"
+        "Level 3C": 20
+        "Level 3D"
+            "Level 4A": 5
+            "Level 4B": 5
+      `,
+      {}
+    );
+  });
+
+  it('7: should handle classDef with multiple styles', () => {
+    imgSnapshotTest(
+      `treemap
+"Main"
+    "A": 20
+    "B":::important
+        "B1": 10
+        "B2": 15
+    "C": 5:::secondary
+
+classDef important fill:#f96,stroke:#333,stroke-width:2px;
+classDef secondary fill:#6cf,stroke:#333,stroke-dasharray:5 5;
+      `,
+      {}
+    );
+  });
+
+  it('8: should handle value formatting', () => {
+    imgSnapshotTest(
+      `%%{init: {'treemap': {'valueFormat': '$0,0'}}}%%
+treemap
+"Budget"
+    "Operations"
+        "Salaries": 700000
+        "Equipment": 200000
+        "Supplies": 100000
+    "Marketing"
+        "Advertising": 400000
+        "Events": 100000
+      `,
+      {}
+    );
+  });
+
+  it('9: should handle a complex example with multiple features', () => {
+    imgSnapshotTest(
+      `%%{init: {'theme': 'dark', 'treemap': {'valueFormat': '$0,0'}}}%%
+treemap
+"Company Budget"
+    "Engineering":::engineering
+        "Frontend": 300000
+        "Backend": 400000
+        "DevOps": 200000
+    "Marketing":::marketing
+        "Digital": 250000
+        "Print": 100000
+        "Events": 150000
+    "Sales":::sales
+        "Direct": 500000
+        "Channel": 300000
+
+classDef engineering fill:#6b9bc3,stroke:#333;
+classDef marketing fill:#c36b9b,stroke:#333;
+classDef sales fill:#c3a66b,stroke:#333;
+      `,
+      {}
+    );
+  });
+
+  it('10: should render the example from documentation', () => {
+    imgSnapshotTest(
+      `
+    treemap
+      "Section 1"
+          "Leaf 1.1": 12
+          "Section 1.2":::class1
+            "Leaf 1.2.1": 12
+      "Section 2"
+          "Leaf 2.1": 20:::class1
+          "Leaf 2.2": 25
+          "Leaf 2.3": 12
+
+      classDef class1 fill:red,color:blue,stroke:#FFD600;
+      `,
+      {}
+    );
+  });
+
+  it('11: should handle comments', () => {
+    imgSnapshotTest(
+      `
+    treemap
+      %% This is a comment
+      "Category A"
+          "Item A1": 10
+          "Item A2": 20
+      %% Another comment
+      "Category B"
+          "Item B1": 15
+          "Item B2": 25
+      `,
+      {}
+    );
+  });
+});
diff --git a/cypress/platform/knsv2.html b/cypress/platform/knsv2.html
index 2518159e5..17052b1cd 100644
--- a/cypress/platform/knsv2.html
+++ b/cypress/platform/knsv2.html
@@ -146,20 +146,17 @@ classDef class1   fill:red,color:blue,stroke:#FFD600;
 
 </pre
     >
-    <pre id="diagram4" class="mermaid2">
-stateDiagram
-  direction TB
-  classDef apa   classDef apa fill:red, color: blue;
-
-  [*] --> Still
-  Still --> [*]
-  Still --> Moving
-  Moving --> Still
-  Moving --> Crash
-  Crash --> [*]
-  Still --> s1
-  class Still apa
-
+    <pre id="diagram4" class="mermaid">
+%%{init: {'treemap': {'valueFormat': '$0,0'}}}%%
+treemap
+"Budget"
+    "Operations"
+        "Salaries": 700000
+        "Equipment": 200000
+        "Supplies": 100000
+    "Marketing"
+        "Advertising": 400000
+        "Events": 100000
 
 </pre
     >