diff --git a/web/app/(site)/webtools/html/page.tsx b/web/app/(site)/webtools/html/page.tsx
index a2bb3ab..9c94ffc 100644
--- a/web/app/(site)/webtools/html/page.tsx
+++ b/web/app/(site)/webtools/html/page.tsx
@@ -1,6 +1,14 @@
 "use client";
 
-import { useState } from "react";
+import { useEffect, useState } from "react";
+
+// import Prism from "prismjs";
+// import "prismjs/themes/prism-tomorrow.css";
+// import "prismjs/components/prism-markup";
+// import "prismjs/components/prism-css";
+// import "prismjs/components/prism-javascript";
+
+import Editor from "@monaco-editor/react";
 
 export default function HtmlPreviewPage() {
   const [html, setHtml] = useState(`<!DOCTYPE html>
@@ -8,34 +16,70 @@ export default function HtmlPreviewPage() {
 <head>
   <title>Preview</title>
 </head>
-<style>
-* {
-background-color: white; }
-</style>
 <body>
   <h1>Hello World</h1>
   <p>HTML hier einfügen...</p>
 </body>
 </html>`);
 
+  const [previewOnly, setPreviewOnly] = useState(false);
+
+  useEffect(() => {
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.key === "F9") {
+        e.preventDefault();
+        setPreviewOnly((v) => !v);
+      }
+    };
+
+    window.addEventListener("keydown", handleKeyDown);
+    return () => window.removeEventListener("keydown", handleKeyDown);
+  }, []);
+
+  if (previewOnly) {
+    return (
+      <iframe
+        title="HTML Preview"
+        srcDoc={html}
+        className="fixed inset-0 w-screen h-screen border-0 bg-white z-50"
+        sandbox="allow-scripts allow-forms allow-modals"
+      />
+    );
+  }
+
   return (
-    <div className="h-[calc(100vh-60px)] flex flex-col">
+    <div className="h-[calc(100vh-60px)] flex flex-col bg-zinc-950">
+      {/* Toolbar */}
+      <div className="flex items-center justify-between px-4 py-2 border-b border-zinc-800 bg-zinc-900">
+        <h1 className="text-sm font-semibold text-zinc-200">
+          HTML Live Preview
+        </h1>
+
+        <button
+          onClick={() => setPreviewOnly(true)}
+          className="px-3 py-1.5 rounded-md bg-zinc-800 hover:bg-zinc-700 text-zinc-200 text-sm transition"
+        >
+          Preview Fullscreen (F9)
+        </button>
+      </div>
+
       {/* Editor */}
-      <div className="h-1/3 border-b">
-        <textarea
+      <div className="relative h-1/3 border-b border-zinc-800">
+        <Editor
+          height="100%"
+          defaultLanguage="html"
           value={html}
-          onChange={(e) => setHtml(e.target.value)}
-          className="w-full h-full p-4 font-mono text-sm resize-none outline-none"
-          placeholder="HTML hier einfügen..."
+          onChange={(value) => setHtml(value || "")}
+          theme="vs-dark"
         />
       </div>
 
       {/* Preview */}
-      <div className="flex-1">
+      <div className="flex-1 bg-white">
         <iframe
           title="HTML Preview"
           srcDoc={html}
-          className="w-full h-full border-0 text-white" 
+          className="w-full h-full border-0"
           sandbox="allow-scripts allow-forms allow-modals"
         />
       </div>
diff --git a/web/bun.lock b/web/bun.lock
index b5bdb3e..f0e3abd 100644
--- a/web/bun.lock
+++ b/web/bun.lock
@@ -4,11 +4,13 @@
     "": {
       "name": "web",
       "dependencies": {
+        "@monaco-editor/react": "^4.7.0",
         "@tailwindcss/typography": "^0.5.19",
         "geist": "^1.7.2",
         "gray-matter": "^4.0.3",
         "next": "16.2.4",
         "next-mdx-remote": "^6.0.0",
+        "prismjs": "^1.30.0",
         "react": "19.2.4",
         "react-diff-viewer-continued": "^4.2.2",
         "react-dom": "19.2.4",
@@ -195,6 +197,10 @@
 
     "@mdx-js/react": ["@mdx-js/react@3.1.1", "", { "dependencies": { "@types/mdx": "^2.0.0" }, "peerDependencies": { "@types/react": ">=16", "react": ">=16" } }, "sha512-f++rKLQgUVYDAtECQ6fn/is15GkEH9+nZPM3MS0RcxVqoTfawHvDlSCH7JbMhAM6uJ32v3eXLvLmLvjGu7PTQw=="],
 
+    "@monaco-editor/loader": ["@monaco-editor/loader@1.7.0", "", { "dependencies": { "state-local": "^1.0.6" } }, "sha512-gIwR1HrJrrx+vfyOhYmCZ0/JcWqG5kbfG7+d3f/C1LXk2EvzAbHSg3MQ5lO2sMlo9izoAZ04shohfKLVT6crVA=="],
+
+    "@monaco-editor/react": ["@monaco-editor/react@4.7.0", "", { "dependencies": { "@monaco-editor/loader": "^1.5.0" }, "peerDependencies": { "monaco-editor": ">= 0.25.0 < 1", "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0", "react-dom": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-cyzXQCtO47ydzxpQtCGSQGOC8Gk3ZUeBXFAxD+CWXYFo5OqZyZUonFl0DwUlTyAfRHntBfw2p3w4s9R6oe1eCA=="],
+
     "@napi-rs/wasm-runtime": ["@napi-rs/wasm-runtime@0.2.12", "", { "dependencies": { "@emnapi/core": "^1.4.3", "@emnapi/runtime": "^1.4.3", "@tybys/wasm-util": "^0.10.0" } }, "sha512-ZVWUcfwY4E/yPitQJl481FjFo3K22D6qF0DuFH6Y/nbnE11GY5uguDxZMGXPQ8WQ0128MXQD7TnfHyK4oWoIJQ=="],
 
     "@next/env": ["@next/env@16.2.4", "", {}, "sha512-dKkkOzOSwFYe5RX6y26fZgkSpVAlIOJKQHIiydQcrWH6y/97+RceSOAdjZ14Qa3zLduVUy0TXcn+EiM6t4rPgw=="],
@@ -313,6 +319,8 @@
 
     "@types/react-dom": ["@types/react-dom@19.2.3", "", { "peerDependencies": { "@types/react": "^19.2.0" } }, "sha512-jp2L/eY6fn+KgVVQAOqYItbF0VY/YApe5Mz2F0aykSO8gx31bYCZyvSeYxCHKvzHG5eZjc+zyaS5BrBWya2+kQ=="],
 
+    "@types/trusted-types": ["@types/trusted-types@2.0.7", "", {}, "sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw=="],
+
     "@types/unist": ["@types/unist@3.0.3", "", {}, "sha512-ko/gIFJRv177XgZsZcBwnqJN5x/Gien8qNOn0D5bQU/zAzVf9Zt3BlcUiLqhV9y4ARk0GbT3tnUiPNgnTXzc/Q=="],
 
     "@typescript-eslint/eslint-plugin": ["@typescript-eslint/eslint-plugin@8.59.0", "", { "dependencies": { "@eslint-community/regexpp": "^4.12.2", "@typescript-eslint/scope-manager": "8.59.0", "@typescript-eslint/type-utils": "8.59.0", "@typescript-eslint/utils": "8.59.0", "@typescript-eslint/visitor-keys": "8.59.0", "ignore": "^7.0.5", "natural-compare": "^1.4.0", "ts-api-utils": "^2.5.0" }, "peerDependencies": { "@typescript-eslint/parser": "^8.59.0", "eslint": "^8.57.0 || ^9.0.0 || ^10.0.0", "typescript": ">=4.8.4 <6.1.0" } }, "sha512-HyAZtpdkgZwpq8Sz3FSUvCR4c+ScbuWa9AksK2Jweub7w4M3yTz4O11AqVJzLYjy/B9ZWPyc81I+mOdJU/bDQw=="],
@@ -503,6 +511,8 @@
 
     "doctrine": ["doctrine@2.1.0", "", { "dependencies": { "esutils": "^2.0.2" } }, "sha512-35mSku4ZXK0vfCuHEDAwt55dg2jNajHZ1odvF+8SSr82EsZY4QmXfuWso8oEd8zRhVObSN18aM0CjSdoBX7zIw=="],
 
+    "dompurify": ["dompurify@3.2.7", "", { "optionalDependencies": { "@types/trusted-types": "^2.0.7" } }, "sha512-WhL/YuveyGXJaerVlMYGWhvQswa7myDG17P7Vu65EWC05o8vfeNbvNf4d/BOvH99+ZW+LlQsc1GDKMa1vNK6dw=="],
+
     "dunder-proto": ["dunder-proto@1.0.1", "", { "dependencies": { "call-bind-apply-helpers": "^1.0.1", "es-errors": "^1.3.0", "gopd": "^1.2.0" } }, "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A=="],
 
     "electron-to-chromium": ["electron-to-chromium@1.5.341", "", {}, "sha512-1sZTssferjgDgaqRTc0ieP+ozzpOy7LQTPTtEW3yQFn4+ORdIAZWV5BthXPyHF7YqLvFJCUPhNhdAJQYlYUgiw=="],
@@ -843,6 +853,8 @@
 
     "markdown-table": ["markdown-table@3.0.4", "", {}, "sha512-wiYz4+JrLyb/DqW2hkFJxP7Vd7JuTDm77fvbM8VfEQdmSMqcImWeeRbHwZjBjIFki/VaMK2BhFi7oUUZeM5bqw=="],
 
+    "marked": ["marked@14.0.0", "", { "bin": { "marked": "bin/marked.js" } }, "sha512-uIj4+faQ+MgHgwUW1l2PsPglZLOLOT1uErt06dAPtx2kjteLAkbsd/0FiYg/MGS+i7ZKLb7w2WClxHkzOOuryQ=="],
+
     "math-intrinsics": ["math-intrinsics@1.1.0", "", {}, "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g=="],
 
     "mdast-util-find-and-replace": ["mdast-util-find-and-replace@3.0.2", "", { "dependencies": { "@types/mdast": "^4.0.0", "escape-string-regexp": "^5.0.0", "unist-util-is": "^6.0.0", "unist-util-visit-parents": "^6.0.0" } }, "sha512-Tmd1Vg/m3Xz43afeNxDIhWRtFZgM2VLyaf4vSTYwudTyeuTneoL3qtWMA5jeLyz/O1vDJmmV4QuScFCA2tBPwg=="],
@@ -957,6 +969,8 @@
 
     "minimist": ["minimist@1.2.8", "", {}, "sha512-2yyAR8qBkN3YuheJanUpWC5U3bb5osDywNB8RzDVlDwDHbocAJveqqj1u8+SVD7jkWT4yvsHCpWqqWqAxb0zCA=="],
 
+    "monaco-editor": ["monaco-editor@0.55.1", "", { "dependencies": { "dompurify": "3.2.7", "marked": "14.0.0" } }, "sha512-jz4x+TJNFHwHtwuV9vA9rMujcZRb0CEilTEwG2rRSpe/A7Jdkuj8xPKttCgOh+v/lkHy7HsZ64oj+q3xoAFl9A=="],
+
     "ms": ["ms@2.1.3", "", {}, "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA=="],
 
     "nanoid": ["nanoid@3.3.11", "", { "bin": { "nanoid": "bin/nanoid.cjs" } }, "sha512-N8SpfPUnUp1bK+PMYW8qSWdl9U+wwNWI4QKxOYDy9JAro3WMX7p2OeVRF9v+347pnakNevPmiHhNmZ2HbFA76w=="],
@@ -1023,6 +1037,8 @@
 
     "prelude-ls": ["prelude-ls@1.2.1", "", {}, "sha512-vkcDPrRZo1QZLbn5RLGPpg/WmIQ65qoWWhcGKf/b5eplkkarX0m9z8ppCat4mlOqUsWpyNuYgO3VRyrYHSzX5g=="],
 
+    "prismjs": ["prismjs@1.30.0", "", {}, "sha512-DEvV2ZF2r2/63V+tK8hQvrR2ZGn10srHbXviTlcv7Kpzw8jWiNTqbVgjO3IY8RxrrOUF8VPMQQFysYYYv0YZxw=="],
+
     "prop-types": ["prop-types@15.8.1", "", { "dependencies": { "loose-envify": "^1.4.0", "object-assign": "^4.1.1", "react-is": "^16.13.1" } }, "sha512-oj87CgZICdulUohogVAR7AjlC0327U4el4L6eAvOqCeudMDVU0NThNaV+b9Df4dXgSP1gXMTnPdhfe/2qDH5cg=="],
 
     "property-information": ["property-information@7.1.0", "", {}, "sha512-TwEZ+X+yCJmYfL7TPUOcvBZ4QfoT5YenQiJuX//0th53DE6w0xxLEtfK3iyryQFddXuvkIk51EEgrJQ0WJkOmQ=="],
@@ -1123,6 +1139,8 @@
 
     "stable-hash": ["stable-hash@0.0.5", "", {}, "sha512-+L3ccpzibovGXFK+Ap/f8LOS0ahMrHTf3xu7mMLSpEGU0EO9ucaysSylKo9eRDFNhWve/y275iPmIZ4z39a9iA=="],
 
+    "state-local": ["state-local@1.0.7", "", {}, "sha512-HTEHMNieakEnoe33shBYcZ7NX83ACUjCu8c40iOGEZsngj9zRnkqS9j1pqQPXwobB0ZcVTk27REb7COQ0UR59w=="],
+
     "stop-iteration-iterator": ["stop-iteration-iterator@1.1.0", "", { "dependencies": { "es-errors": "^1.3.0", "internal-slot": "^1.1.0" } }, "sha512-eLoXW/DHyl62zxY4SCaIgnRhuMr6ri4juEYARS8E6sCEqzKpOiE521Ucofdx+KnDZl5xmvGYaaKCk5FEOxJCoQ=="],
 
     "string.prototype.includes": ["string.prototype.includes@2.0.1", "", { "dependencies": { "call-bind": "^1.0.7", "define-properties": "^1.2.1", "es-abstract": "^1.23.3" } }, "sha512-o7+c9bW6zpAdJHTtujeePODAhkuicdAryFsfVKwA+wGw89wJ4GTY484WTucM9hLtDEOpOvI+aHnzqnC5lHp4Rg=="],
diff --git a/web/package-lock.json b/web/package-lock.json
index f62cdb2..17d10d9 100644
--- a/web/package-lock.json
+++ b/web/package-lock.json
@@ -8,11 +8,13 @@
       "name": "web",
       "version": "0.1.0",
       "dependencies": {
+        "@monaco-editor/react": "^4.7.0",
         "@tailwindcss/typography": "^0.5.19",
         "geist": "^1.7.2",
         "gray-matter": "^4.0.3",
         "next": "16.2.4",
         "next-mdx-remote": "^6.0.0",
+        "prismjs": "^1.30.0",
         "react": "19.2.4",
         "react-diff-viewer-continued": "^4.2.2",
         "react-dom": "19.2.4",
@@ -27,6 +29,7 @@
         "@tailwindcss/postcss": "^4",
         "@tauri-apps/cli": "^2",
         "@types/node": "^20",
+        "@types/prismjs": "^1.26.6",
         "@types/react": "^19",
         "@types/react-dom": "^19",
         "eslint": "^9",
@@ -1238,6 +1241,29 @@
         "react": ">=16"
       }
     },
+    "node_modules/@monaco-editor/loader": {
+      "version": "1.7.0",
+      "resolved": "https://registry.npmjs.org/@monaco-editor/loader/-/loader-1.7.0.tgz",
+      "integrity": "sha512-gIwR1HrJrrx+vfyOhYmCZ0/JcWqG5kbfG7+d3f/C1LXk2EvzAbHSg3MQ5lO2sMlo9izoAZ04shohfKLVT6crVA==",
+      "license": "MIT",
+      "dependencies": {
+        "state-local": "^1.0.6"
+      }
+    },
+    "node_modules/@monaco-editor/react": {
+      "version": "4.7.0",
+      "resolved": "https://registry.npmjs.org/@monaco-editor/react/-/react-4.7.0.tgz",
+      "integrity": "sha512-cyzXQCtO47ydzxpQtCGSQGOC8Gk3ZUeBXFAxD+CWXYFo5OqZyZUonFl0DwUlTyAfRHntBfw2p3w4s9R6oe1eCA==",
+      "license": "MIT",
+      "dependencies": {
+        "@monaco-editor/loader": "^1.5.0"
+      },
+      "peerDependencies": {
+        "monaco-editor": ">= 0.25.0 < 1",
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0",
+        "react-dom": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
     "node_modules/@napi-rs/wasm-runtime": {
       "version": "1.1.5",
       "resolved": "https://registry.npmjs.org/@napi-rs/wasm-runtime/-/wasm-runtime-1.1.5.tgz",
@@ -2060,6 +2086,13 @@
       "integrity": "sha512-dISoDXWWQwUquiKsyZ4Ng+HX2KsPL7LyHKHQwgGFEA3IaKac4Obd+h2a/a6waisAoepJlBcx9paWqjA8/HVjCw==",
       "license": "MIT"
     },
+    "node_modules/@types/prismjs": {
+      "version": "1.26.6",
+      "resolved": "https://registry.npmjs.org/@types/prismjs/-/prismjs-1.26.6.tgz",
+      "integrity": "sha512-vqlvI7qlMvcCBbVe0AKAb4f97//Hy0EBTaiW8AalRnG/xAN5zOiWWyrNqNXeq8+KAuvRewjCVY1+IPxk4RdNYw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/react": {
       "version": "19.2.17",
       "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.17.tgz",
@@ -2079,6 +2112,14 @@
         "@types/react": "^19.2.0"
       }
     },
+    "node_modules/@types/trusted-types": {
+      "version": "2.0.7",
+      "resolved": "https://registry.npmjs.org/@types/trusted-types/-/trusted-types-2.0.7.tgz",
+      "integrity": "sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw==",
+      "license": "MIT",
+      "optional": true,
+      "peer": true
+    },
     "node_modules/@types/unist": {
       "version": "3.0.3",
       "resolved": "https://registry.npmjs.org/@types/unist/-/unist-3.0.3.tgz",
@@ -3574,6 +3615,16 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/dompurify": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.2.7.tgz",
+      "integrity": "sha512-WhL/YuveyGXJaerVlMYGWhvQswa7myDG17P7Vu65EWC05o8vfeNbvNf4d/BOvH99+ZW+LlQsc1GDKMa1vNK6dw==",
+      "license": "(MPL-2.0 OR Apache-2.0)",
+      "peer": true,
+      "optionalDependencies": {
+        "@types/trusted-types": "^2.0.7"
+      }
+    },
     "node_modules/dunder-proto": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
@@ -6159,6 +6210,19 @@
         "url": "https://github.com/sponsors/wooorm"
       }
     },
+    "node_modules/marked": {
+      "version": "14.0.0",
+      "resolved": "https://registry.npmjs.org/marked/-/marked-14.0.0.tgz",
+      "integrity": "sha512-uIj4+faQ+MgHgwUW1l2PsPglZLOLOT1uErt06dAPtx2kjteLAkbsd/0FiYg/MGS+i7ZKLb7w2WClxHkzOOuryQ==",
+      "license": "MIT",
+      "peer": true,
+      "bin": {
+        "marked": "bin/marked.js"
+      },
+      "engines": {
+        "node": ">= 18"
+      }
+    },
     "node_modules/math-intrinsics": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
@@ -7238,6 +7302,17 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/monaco-editor": {
+      "version": "0.55.1",
+      "resolved": "https://registry.npmjs.org/monaco-editor/-/monaco-editor-0.55.1.tgz",
+      "integrity": "sha512-jz4x+TJNFHwHtwuV9vA9rMujcZRb0CEilTEwG2rRSpe/A7Jdkuj8xPKttCgOh+v/lkHy7HsZ64oj+q3xoAFl9A==",
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "dompurify": "3.2.7",
+        "marked": "14.0.0"
+      }
+    },
     "node_modules/ms": {
       "version": "2.1.3",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
@@ -7779,6 +7854,15 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/prismjs": {
+      "version": "1.30.0",
+      "resolved": "https://registry.npmjs.org/prismjs/-/prismjs-1.30.0.tgz",
+      "integrity": "sha512-DEvV2ZF2r2/63V+tK8hQvrR2ZGn10srHbXviTlcv7Kpzw8jWiNTqbVgjO3IY8RxrrOUF8VPMQQFysYYYv0YZxw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/prop-types": {
       "version": "15.8.1",
       "resolved": "https://registry.npmjs.org/prop-types/-/prop-types-15.8.1.tgz",
@@ -8562,6 +8646,12 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/state-local": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/state-local/-/state-local-1.0.7.tgz",
+      "integrity": "sha512-HTEHMNieakEnoe33shBYcZ7NX83ACUjCu8c40iOGEZsngj9zRnkqS9j1pqQPXwobB0ZcVTk27REb7COQ0UR59w==",
+      "license": "MIT"
+    },
     "node_modules/stop-iteration-iterator": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/stop-iteration-iterator/-/stop-iteration-iterator-1.1.0.tgz",
diff --git a/web/package.json b/web/package.json
index 3d4ac14..f814097 100644
--- a/web/package.json
+++ b/web/package.json
@@ -10,11 +10,13 @@
     "tauri": "NEXT_CONFIG_FILE=next.config.tauri.ts tauri"
   },
   "dependencies": {
+    "@monaco-editor/react": "^4.7.0",
     "@tailwindcss/typography": "^0.5.19",
     "geist": "^1.7.2",
     "gray-matter": "^4.0.3",
     "next": "16.2.4",
     "next-mdx-remote": "^6.0.0",
+    "prismjs": "^1.30.0",
     "react": "19.2.4",
     "react-diff-viewer-continued": "^4.2.2",
     "react-dom": "19.2.4",
@@ -29,6 +31,7 @@
     "@tailwindcss/postcss": "^4",
     "@tauri-apps/cli": "^2",
     "@types/node": "^20",
+    "@types/prismjs": "^1.26.6",
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "eslint": "^9",
