diff --git a/backends/a/index.html b/backends/a/index.html
index 85c42ed..9dce552 100644
--- a/backends/a/index.html
+++ b/backends/a/index.html
@@ -6,12 +6,16 @@
     <title>Backend A</title>
     <style>
       :root {
-        --bg: #0f1b2e;
-        --card: #173252;
-        --line: #3a6e96;
-        --text: #e9f2fb;
-        --muted: #b6cce0;
-        --accent: #4ecdc4;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --accent: #00739f;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -23,49 +27,101 @@
         min-height: 100vh;
         display: grid;
         place-items: center;
-        padding: 1rem;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        padding: 1.5rem;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background: radial-gradient(circle at top right, #22456b, var(--bg) 60%);
+        background: var(--bg);
       }
 
       main {
+        position: relative;
         width: min(760px, 100%);
-        background: var(--card);
+        background: var(--surface);
         border: 1px solid var(--line);
-        border-radius: 14px;
-        padding: 1.1rem;
+        border-radius: 16px;
+        padding: 1.8rem;
+        box-shadow: var(--shadow);
+        overflow: hidden;
+      }
+
+      main::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        left: 0;
+        right: 0;
+        height: 5px;
+        background: var(--accent);
+      }
+
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1.4rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.45rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.78rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
       }
 
       h1 {
-        margin-top: 0;
+        margin: 0.2rem 0 0.6rem;
+        font-weight: 800;
+        letter-spacing: -0.01em;
       }
 
       p {
         color: var(--muted);
+        line-height: 1.55;
       }
 
       code {
-        background: #0f2438;
-        border: 1px solid #2d587a;
+        font-family: "JetBrains Mono", "Fira Code", "Consolas", monospace;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       .tag {
         display: inline-block;
         background: var(--accent);
-        color: #072420;
+        color: #ffffff;
         border-radius: 999px;
-        padding: 0.15rem 0.55rem;
+        padding: 0.2rem 0.65rem;
         font-weight: 700;
-        font-size: 0.85rem;
+        font-size: 0.8rem;
+        letter-spacing: 0.03em;
       }
     </style>
   </head>
   <body>
     <!-- INSTANCE=A -->
     <main>
+      <div class="brand">
+        <span class="tmark"><b>T</b></span>
+        <span>Telekom Security</span>
+      </div>
       <span class="tag">Backend A</span>
       <h1>Reverse Proxy Target A</h1>
       <p>This page is served by backend A and reached through Nginx reverse proxy.</p>
diff --git a/backends/a2/index.html b/backends/a2/index.html
index 9b1dc50..c30fc91 100644
--- a/backends/a2/index.html
+++ b/backends/a2/index.html
@@ -6,41 +6,112 @@
     <title>Backend A2</title>
     <style>
       :root {
-        --bg: #102335;
-        --card: #1d3f61;
-        --line: #4f86b3;
-        --text: #e9f2fb;
-        --muted: #c0d5e8;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --accent: #4b9fc4;
+        --line: #e5e5ea;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
-      * { box-sizing: border-box; }
+      * {
+        box-sizing: border-box;
+      }
 
       body {
         margin: 0;
         min-height: 100vh;
         display: grid;
         place-items: center;
-        padding: 1rem;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        padding: 1.5rem;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background: radial-gradient(circle at top left, #315e86, var(--bg) 60%);
+        background: var(--bg);
       }
 
       main {
+        position: relative;
         width: min(760px, 100%);
-        background: var(--card);
+        background: var(--surface);
         border: 1px solid var(--line);
-        border-radius: 14px;
-        padding: 1.1rem;
+        border-radius: 16px;
+        padding: 1.8rem;
+        box-shadow: var(--shadow);
+        overflow: hidden;
       }
 
-      h1 { margin-top: 0; }
-      p { color: var(--muted); }
+      main::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        left: 0;
+        right: 0;
+        height: 5px;
+        background: var(--accent);
+      }
+
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1.4rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.45rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.78rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
+      }
+
+      h1 {
+        margin: 0.2rem 0 0.6rem;
+        font-weight: 800;
+        letter-spacing: -0.01em;
+      }
+
+      p {
+        color: var(--muted);
+        line-height: 1.55;
+      }
+
+      .tag {
+        display: inline-block;
+        background: var(--accent);
+        color: #ffffff;
+        border-radius: 999px;
+        padding: 0.2rem 0.65rem;
+        font-weight: 700;
+        font-size: 0.8rem;
+        letter-spacing: 0.03em;
+      }
     </style>
   </head>
   <body>
     <!-- INSTANCE=A2 -->
     <main>
+      <div class="brand">
+        <span class="tmark"><b>T</b></span>
+        <span>Telekom Security</span>
+      </div>
+      <span class="tag">Backend A2</span>
       <h1>Reverse Proxy Target A2</h1>
       <p>Use this page to validate load balancing between backend-a and backend-a2.</p>
     </main>
diff --git a/backends/b/index.html b/backends/b/index.html
index 5e208f4..6dc4953 100644
--- a/backends/b/index.html
+++ b/backends/b/index.html
@@ -6,12 +6,16 @@
     <title>Backend B</title>
     <style>
       :root {
-        --bg: #1e1308;
-        --card: #3a2412;
-        --line: #8a5b34;
-        --text: #fff4ea;
-        --muted: #f0d5bf;
-        --accent: #ffd166;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --accent: #b97400;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -23,48 +27,100 @@
         min-height: 100vh;
         display: grid;
         place-items: center;
-        padding: 1rem;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        padding: 1.5rem;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background: radial-gradient(circle at top left, #5a371d, var(--bg) 60%);
+        background: var(--bg);
       }
 
       main {
+        position: relative;
         width: min(760px, 100%);
-        background: var(--card);
+        background: var(--surface);
         border: 1px solid var(--line);
-        border-radius: 14px;
-        padding: 1.1rem;
+        border-radius: 16px;
+        padding: 1.8rem;
+        box-shadow: var(--shadow);
+        overflow: hidden;
+      }
+
+      main::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        left: 0;
+        right: 0;
+        height: 5px;
+        background: var(--accent);
+      }
+
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1.4rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.45rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.78rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
       }
 
       h1 {
-        margin-top: 0;
+        margin: 0.2rem 0 0.6rem;
+        font-weight: 800;
+        letter-spacing: -0.01em;
       }
 
       p {
         color: var(--muted);
+        line-height: 1.55;
       }
 
       code {
-        background: #2a190d;
-        border: 1px solid #7d4f29;
+        font-family: "JetBrains Mono", "Fira Code", "Consolas", monospace;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       .tag {
         display: inline-block;
         background: var(--accent);
-        color: #3a2300;
+        color: #ffffff;
         border-radius: 999px;
-        padding: 0.15rem 0.55rem;
+        padding: 0.2rem 0.65rem;
         font-weight: 700;
-        font-size: 0.85rem;
+        font-size: 0.8rem;
+        letter-spacing: 0.03em;
       }
     </style>
   </head>
   <body>
     <main>
+      <div class="brand">
+        <span class="tmark"><b>T</b></span>
+        <span>Telekom Security</span>
+      </div>
       <span class="tag">Backend B</span>
       <h1>Reverse Proxy Target B</h1>
       <p>This page is served by backend B and reached through Nginx reverse proxy.</p>
diff --git a/backends/c/index.html b/backends/c/index.html
index 1451557..14514c9 100644
--- a/backends/c/index.html
+++ b/backends/c/index.html
@@ -6,12 +6,16 @@
     <title>Backend C</title>
     <style>
       :root {
-        --bg: #0b1f10;
-        --card: #174028;
-        --line: #2e7a47;
-        --text: #e7f9ec;
-        --muted: #b5dec1;
-        --accent: #84e3a1;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --accent: #46a800;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -23,48 +27,100 @@
         min-height: 100vh;
         display: grid;
         place-items: center;
-        padding: 1rem;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        padding: 1.5rem;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background: radial-gradient(circle at top center, #245939, var(--bg) 60%);
+        background: var(--bg);
       }
 
       main {
+        position: relative;
         width: min(760px, 100%);
-        background: var(--card);
+        background: var(--surface);
         border: 1px solid var(--line);
-        border-radius: 14px;
-        padding: 1.1rem;
+        border-radius: 16px;
+        padding: 1.8rem;
+        box-shadow: var(--shadow);
+        overflow: hidden;
+      }
+
+      main::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        left: 0;
+        right: 0;
+        height: 5px;
+        background: var(--accent);
+      }
+
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1.4rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.45rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.78rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
       }
 
       h1 {
-        margin-top: 0;
+        margin: 0.2rem 0 0.6rem;
+        font-weight: 800;
+        letter-spacing: -0.01em;
       }
 
       p {
         color: var(--muted);
+        line-height: 1.55;
       }
 
       code {
-        background: #113121;
-        border: 1px solid #2f7047;
+        font-family: "JetBrains Mono", "Fira Code", "Consolas", monospace;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       .tag {
         display: inline-block;
         background: var(--accent);
-        color: #083117;
+        color: #ffffff;
         border-radius: 999px;
-        padding: 0.15rem 0.55rem;
+        padding: 0.2rem 0.65rem;
         font-weight: 700;
-        font-size: 0.85rem;
+        font-size: 0.8rem;
+        letter-spacing: 0.03em;
       }
     </style>
   </head>
   <body>
     <main>
+      <div class="brand">
+        <span class="tmark"><b>T</b></span>
+        <span>Telekom Security</span>
+      </div>
       <span class="tag">Backend C</span>
       <h1>Reverse Proxy Target C</h1>
       <p>This is a starter page for challenge 2.</p>
diff --git a/proxy/html/challenges.html b/proxy/html/challenges.html
index 9ba4104..24c6361 100644
--- a/proxy/html/challenges.html
+++ b/proxy/html/challenges.html
@@ -6,16 +6,17 @@
     <title>HTL Workshop Challenges</title>
     <style>
       :root {
-        --bg: #081825;
-        --panel: #10273d;
-        --panel-soft: #163450;
-        --text: #e9f2fb;
-        --muted: #b7cbdf;
-        --accent: #4ecdc4;
-        --easy: #59d68a;
-        --medium: #ffd166;
-        --hard: #ff7b72;
-        --expert: #6fb6ff;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --magenta-soft: #fbe3f0;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --radius: 16px;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -24,62 +25,94 @@
 
       body {
         margin: 0;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background:
-          radial-gradient(circle at 100% 0%, #1f4060 0%, transparent 45%),
-          radial-gradient(circle at 0% 100%, #14324a 0%, transparent 35%),
-          var(--bg);
+        background: var(--bg);
         min-height: 100vh;
-        padding: 1.2rem;
+        padding: 2.2rem 1.2rem 3rem;
+        line-height: 1.55;
       }
 
       main {
         width: min(1150px, 100%);
         margin: 0 auto;
         display: grid;
-        gap: 1rem;
+        gap: 1.25rem;
       }
 
       .panel {
-        background: var(--panel);
-        border: 1px solid #315678;
-        border-radius: 14px;
-        padding: 1.1rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
+        border-radius: var(--radius);
+        padding: 1.5rem 1.6rem;
+        box-shadow: var(--shadow);
+      }
+
+      .hero {
+        position: relative;
+        overflow: hidden;
+      }
+
+      .hero::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        bottom: 0;
+        left: 0;
+        width: 5px;
+        background: var(--magenta);
       }
 
       h1,
       h2,
       h3 {
         margin-top: 0;
+        font-weight: 800;
+        letter-spacing: -0.01em;
+        color: var(--text);
+      }
+
+      h1 {
+        font-size: 1.95rem;
+      }
+
+      h2 {
+        font-size: 1.3rem;
       }
 
       p,
       li {
         color: var(--muted);
-        line-height: 1.5;
+        line-height: 1.55;
       }
 
       a {
-        color: var(--accent);
+        color: var(--magenta);
+        text-decoration: none;
+        font-weight: 600;
+      }
+
+      a:hover {
+        text-decoration: underline;
       }
 
       code {
         font-family: "JetBrains Mono", "Fira Code", "Consolas", "Liberation Mono", monospace;
-        font-size: 0.92em;
-        background: #0d1f31;
-        border: 1px solid #2d4f6e;
+        font-size: 0.9em;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       pre {
-        background: #0b2133;
-        border: 1px solid #2b5578;
-        border-radius: 10px;
-        padding: 0.75rem 0.85rem;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
+        border-radius: 12px;
+        padding: 0.9rem 1rem;
         overflow-x: auto;
-        margin: 0.65rem 0;
+        margin: 0.7rem 0 0;
       }
 
       pre code {
@@ -88,61 +121,110 @@
         border: 0;
         border-radius: 0;
         padding: 0;
-        font-size: 0.92rem;
-        line-height: 1.45;
+        font-size: 0.88rem;
+        line-height: 1.5;
         white-space: pre;
+        color: #2a2a30;
       }
 
-      .top-links {
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.55rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.82rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
+      }
+
+      .nav {
         display: flex;
         flex-wrap: wrap;
         gap: 0.5rem;
+        margin-top: 1.2rem;
       }
 
-      .pill {
-        display: inline-block;
+      .nav a {
         text-decoration: none;
-        background: #11314b;
-        border: 1px solid #2a5d84;
+        color: var(--text);
+        font-weight: 600;
+        font-size: 0.92rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 999px;
-        padding: 0.35rem 0.75rem;
+        padding: 0.45rem 0.95rem;
+        transition:
+          color 0.15s ease,
+          border-color 0.15s ease;
+      }
+
+      .nav a:hover {
+        border-color: var(--magenta);
+        color: var(--magenta);
+        text-decoration: none;
       }
 
       .badge {
         display: inline-block;
         border-radius: 999px;
-        padding: 0.15rem 0.5rem;
-        font-size: 0.8rem;
+        padding: 0.2rem 0.6rem;
+        font-size: 0.7rem;
         font-weight: 700;
-        margin-bottom: 0.45rem;
+        letter-spacing: 0.05em;
+        text-transform: uppercase;
       }
 
       .easy {
-        color: #08210f;
-        background: var(--easy);
+        color: #245c00;
+        background: #e4f3d6;
       }
 
       .medium {
-        color: #312200;
-        background: var(--medium);
+        color: #7a4d00;
+        background: #fdeecb;
       }
 
       .hard {
-        color: #3b0905;
-        background: var(--hard);
+        color: #8a0010;
+        background: #fbdcdc;
       }
 
       .expert {
-        color: #031c37;
-        background: var(--expert);
+        color: #004b66;
+        background: #d6eef7;
       }
 
       details {
-        background: var(--panel-soft);
-        border: 1px solid #2d5577;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 12px;
-        padding: 0.75rem 0.85rem;
-        margin-bottom: 0.7rem;
+        padding: 1rem 1.15rem;
+        margin-bottom: 0.8rem;
+        transition: border-color 0.15s ease;
+      }
+
+      details[open] {
+        border-color: #d8d8df;
+        box-shadow: var(--shadow);
       }
 
       details:last-child {
@@ -152,28 +234,54 @@
       summary {
         cursor: pointer;
         font-weight: 700;
+        color: var(--text);
+        list-style: none;
+        display: flex;
+        align-items: center;
+        gap: 0.6rem;
+      }
+
+      summary::-webkit-details-marker {
+        display: none;
+      }
+
+      summary::after {
+        content: "+";
+        margin-left: auto;
+        color: var(--magenta);
+        font-weight: 800;
+        font-size: 1.15rem;
+        line-height: 1;
+      }
+
+      details[open] summary::after {
+        content: "\2013";
       }
 
       .kw {
-        color: #e9f2fb;
+        color: var(--text);
         font-weight: 700;
       }
     </style>
   </head>
   <body>
     <main>
-      <section class="panel">
-        <h1>Challenges - Reverse Proxy & TLS</h1>
-        <p>Manuelle Proxy-Konfiguration, Security-Entscheidungen und TLS von Grund auf.</p>
-        <div class="top-links">
-          <a class="pill" href="/">Startseite</a>
-          <a class="pill" href="/challenges.html">Challenges</a>
-          <a class="pill" href="/hints.html">Hints</a>
-          <a class="pill" href="/solutions.html">Solutions</a>
-          <a class="pill" href="/service/a">Backend A</a>
-          <a class="pill" href="/service/b">Backend B</a>
-          <a class="pill" href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
+      <section class="panel hero">
+        <div class="brand">
+          <span class="tmark"><b>T</b></span>
+          <span>Telekom Security</span>
         </div>
+        <h1>Challenges - Reverse Proxy &amp; TLS</h1>
+        <p>Manuelle Proxy-Konfiguration, Security-Entscheidungen und TLS von Grund auf.</p>
+        <nav class="nav">
+          <a href="/">Startseite</a>
+          <a href="/challenges.html">Challenges</a>
+          <a href="/hints.html">Hints</a>
+          <a href="/solutions.html">Solutions</a>
+          <a href="/service/a">Backend A</a>
+          <a href="/service/b">Backend B</a>
+          <a href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
+        </nav>
       </section>
 
       <section class="panel">
diff --git a/proxy/html/hints.html b/proxy/html/hints.html
index 1cba4d1..2d8b704 100644
--- a/proxy/html/hints.html
+++ b/proxy/html/hints.html
@@ -6,12 +6,17 @@
     <title>HTL Workshop Hint Cheatsheet</title>
     <style>
       :root {
-        --bg: #081825;
-        --panel: #10273d;
-        --panel-soft: #163450;
-        --text: #e9f2fb;
-        --muted: #b7cbdf;
-        --accent: #4ecdc4;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --magenta-soft: #fbe3f0;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --radius: 16px;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -20,75 +25,109 @@
 
       body {
         margin: 0;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background:
-          radial-gradient(circle at 100% 0%, #1f4060 0%, transparent 45%),
-          radial-gradient(circle at 0% 100%, #14324a 0%, transparent 35%),
-          var(--bg);
+        background: var(--bg);
         min-height: 100vh;
-        padding: 1.2rem;
+        padding: 2.2rem 1.2rem 3rem;
+        line-height: 1.55;
       }
 
       main {
         width: min(1100px, 100%);
         margin: 0 auto;
         display: grid;
-        gap: 1rem;
+        gap: 1.25rem;
       }
 
       .panel {
-        background: var(--panel);
-        border: 1px solid #315678;
-        border-radius: 14px;
-        padding: 1.1rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
+        border-radius: var(--radius);
+        padding: 1.5rem 1.6rem;
+        box-shadow: var(--shadow);
       }
 
-      .grid {
-        display: grid;
-        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
-        gap: 0.8rem;
+      .hero {
+        position: relative;
+        overflow: hidden;
       }
 
-      .card {
-        background: var(--panel-soft);
-        border: 1px solid #2d5577;
-        border-radius: 12px;
-        padding: 0.9rem;
+      .hero::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        bottom: 0;
+        left: 0;
+        width: 5px;
+        background: var(--magenta);
       }
 
       h1,
       h2,
       h3 {
         margin-top: 0;
+        font-weight: 800;
+        letter-spacing: -0.01em;
+        color: var(--text);
+      }
+
+      h1 {
+        font-size: 1.95rem;
+      }
+
+      h2 {
+        font-size: 1.3rem;
+      }
+
+      h3 {
+        font-size: 1.02rem;
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+      }
+
+      h3::before {
+        content: "";
+        width: 8px;
+        height: 8px;
+        border-radius: 2px;
+        background: var(--magenta);
       }
 
       p,
       li {
         color: var(--muted);
-        line-height: 1.5;
+        line-height: 1.55;
       }
 
       a {
-        color: var(--accent);
+        color: var(--magenta);
+        text-decoration: none;
+        font-weight: 600;
+      }
+
+      a:hover {
+        text-decoration: underline;
       }
 
       code {
         font-family: "JetBrains Mono", "Fira Code", "Consolas", "Liberation Mono", monospace;
-        font-size: 0.92em;
-        background: #0d1f31;
-        border: 1px solid #2d4f6e;
+        font-size: 0.9em;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       pre {
-        background: #0b2133;
-        border: 1px solid #2b5578;
-        border-radius: 10px;
-        padding: 0.75rem 0.85rem;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
+        border-radius: 12px;
+        padding: 0.9rem 1rem;
         overflow-x: auto;
-        margin: 0.65rem 0;
+        margin: 0.7rem 0;
       }
 
       pre code {
@@ -97,49 +136,108 @@
         border: 0;
         border-radius: 0;
         padding: 0;
-        font-size: 0.92rem;
-        line-height: 1.45;
+        font-size: 0.88rem;
+        line-height: 1.5;
         white-space: pre;
+        color: #2a2a30;
       }
 
-      .top-links {
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.55rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.82rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
+      }
+
+      .nav {
         display: flex;
         flex-wrap: wrap;
         gap: 0.5rem;
+        margin-top: 1.2rem;
       }
 
-      .pill {
-        display: inline-block;
+      .nav a {
         text-decoration: none;
-        background: #11314b;
-        border: 1px solid #2a5d84;
+        color: var(--text);
+        font-weight: 600;
+        font-size: 0.92rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 999px;
-        padding: 0.35rem 0.75rem;
+        padding: 0.45rem 0.95rem;
+        transition:
+          color 0.15s ease,
+          border-color 0.15s ease;
+      }
+
+      .nav a:hover {
+        border-color: var(--magenta);
+        color: var(--magenta);
+        text-decoration: none;
+      }
+
+      .grid {
+        display: grid;
+        grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
+        gap: 1rem;
+      }
+
+      .card {
+        background: var(--surface);
+        border: 1px solid var(--line);
+        border-radius: 12px;
+        padding: 1.1rem 1.2rem;
       }
     </style>
   </head>
   <body>
     <main>
-      <section class="panel">
+      <section class="panel hero">
+        <div class="brand">
+          <span class="tmark"><b>T</b></span>
+          <span>Telekom Security</span>
+        </div>
         <h1>Hint Cheatsheet</h1>
         <p>
           Kompakte Hilfe fuer Setup, TLS und Wireshark. Fuer komplette Aufgaben siehe das
           <a href="/challenges.html">Challenge Board</a> und fuer Korrekturhilfe das
           <a href="/solutions.html">Solutions Board</a>.
         </p>
-        <div class="top-links">
-          <a class="pill" href="/">Startseite</a>
-          <a class="pill" href="/challenges.html">Challenges</a>
-          <a class="pill" href="/hints.html">Hints</a>
-          <a class="pill" href="/solutions.html">Solutions</a>
-          <a class="pill" href="/service/a">Backend A</a>
-          <a class="pill" href="/service/b">Backend B</a>
-          <a class="pill" href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
-        </div>
+        <nav class="nav">
+          <a href="/">Startseite</a>
+          <a href="/challenges.html">Challenges</a>
+          <a href="/hints.html">Hints</a>
+          <a href="/solutions.html">Solutions</a>
+          <a href="/service/a">Backend A</a>
+          <a href="/service/b">Backend B</a>
+          <a href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
+        </nav>
       </section>
 
       <section class="panel">
-        <h2>Deploy & Reset</h2>
+        <h2>Deploy &amp; Reset</h2>
         <div class="grid">
           <article class="card">
             <h3>Start</h3>
@@ -163,7 +261,7 @@
       </section>
 
       <section class="panel">
-        <h2>Easy-RSA & CA Import</h2>
+        <h2>Easy-RSA &amp; CA Import</h2>
         <div class="grid">
           <article class="card">
             <h3>PKI Quickstart</h3>
diff --git a/proxy/html/index.html b/proxy/html/index.html
index fbd30bd..ca589f3 100644
--- a/proxy/html/index.html
+++ b/proxy/html/index.html
@@ -6,13 +6,17 @@
     <title>HTL Reverse Proxy Lab</title>
     <style>
       :root {
-        --bg: #081825;
-        --panel: #10273d;
-        --panel-soft: #163450;
-        --text: #e9f2fb;
-        --muted: #b7cbdf;
-        --accent: #4ecdc4;
-        --line: #315678;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --magenta-soft: #fbe3f0;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --radius: 16px;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -21,101 +25,201 @@
 
       body {
         margin: 0;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background:
-          radial-gradient(circle at 100% 0%, #1f4060 0%, transparent 45%),
-          radial-gradient(circle at 0% 100%, #14324a 0%, transparent 35%),
-          var(--bg);
+        background: var(--bg);
         min-height: 100vh;
-        padding: 1.2rem;
+        padding: 2.2rem 1.2rem 3rem;
+        line-height: 1.55;
       }
 
       main {
         width: min(1100px, 100%);
         margin: 0 auto;
         display: grid;
-        gap: 1rem;
+        gap: 1.25rem;
       }
 
       .panel {
-        background: var(--panel);
+        background: var(--surface);
         border: 1px solid var(--line);
-        border-radius: 14px;
-        padding: 1.1rem;
+        border-radius: var(--radius);
+        padding: 1.5rem 1.6rem;
+        box-shadow: var(--shadow);
+      }
+
+      .hero {
+        position: relative;
+        overflow: hidden;
+      }
+
+      .hero::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        bottom: 0;
+        left: 0;
+        width: 5px;
+        background: var(--magenta);
       }
 
       h1,
       h2,
       h3 {
         margin-top: 0;
+        font-weight: 800;
+        letter-spacing: -0.01em;
+        color: var(--text);
+      }
+
+      h1 {
+        font-size: 1.95rem;
+      }
+
+      h2 {
+        font-size: 1.3rem;
       }
 
       p,
       li {
         color: var(--muted);
-        line-height: 1.5;
+        line-height: 1.55;
       }
 
       code {
         font-family: "JetBrains Mono", "Fira Code", "Consolas", "Liberation Mono", monospace;
-        font-size: 0.92em;
-        background: #0d1f31;
-        border: 1px solid #2d4f6e;
+        font-size: 0.9em;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       a {
-        color: var(--accent);
+        color: var(--magenta);
+        text-decoration: none;
+        font-weight: 600;
       }
 
-      .top-links {
+      a:hover {
+        text-decoration: underline;
+      }
+
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.55rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.82rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
+      }
+
+      .nav {
         display: flex;
         flex-wrap: wrap;
         gap: 0.5rem;
+        margin-top: 1.2rem;
       }
 
-      .pill {
-        display: inline-block;
+      .nav a {
         text-decoration: none;
-        background: #11314b;
-        border: 1px solid #2a5d84;
+        color: var(--text);
+        font-weight: 600;
+        font-size: 0.92rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 999px;
-        padding: 0.35rem 0.75rem;
+        padding: 0.45rem 0.95rem;
+        transition:
+          color 0.15s ease,
+          border-color 0.15s ease;
+      }
+
+      .nav a:hover {
+        border-color: var(--magenta);
+        color: var(--magenta);
+        text-decoration: none;
       }
 
       .grid {
         display: grid;
         grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
-        gap: 0.8rem;
+        gap: 1rem;
       }
 
       .card {
-        background: var(--panel-soft);
-        border: 1px solid #2d5577;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 12px;
-        padding: 0.9rem;
+        padding: 1.1rem 1.2rem;
+      }
+
+      .card h3 {
+        display: flex;
+        align-items: center;
+        gap: 0.5rem;
+      }
+
+      .card h3::before {
+        content: "";
+        width: 8px;
+        height: 8px;
+        border-radius: 2px;
+        background: var(--magenta);
+      }
+
+      ul {
+        padding-left: 1.1rem;
+        margin: 0.4rem 0 0;
+      }
+
+      li {
+        margin-bottom: 0.25rem;
       }
     </style>
   </head>
   <body>
     <main>
-      <section class="panel">
-        <h1>HTL Reverse Proxy & TLS Lab</h1>
+      <section class="panel hero">
+        <div class="brand">
+          <span class="tmark"><b>T</b></span>
+          <span>Telekom Security</span>
+        </div>
+        <h1>HTL Reverse Proxy &amp; TLS Lab</h1>
         <p>
           Basis laeuft mit HTTP. Ziel im Workshop: Reverse Proxy verstehen und HTTPS/TLS manuell
           aufbauen.
         </p>
-        <div class="top-links">
-          <a class="pill" href="/">Startseite</a>
-          <a class="pill" href="/challenges.html">Challenges</a>
-          <a class="pill" href="/hints.html">Hints</a>
-          <a class="pill" href="/solutions.html">Solutions</a>
-          <a class="pill" href="/service/a">Backend A</a>
-          <a class="pill" href="/service/b">Backend B</a>
-          <a class="pill" href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
-        </div>
+        <nav class="nav">
+          <a href="/">Startseite</a>
+          <a href="/challenges.html">Challenges</a>
+          <a href="/hints.html">Hints</a>
+          <a href="/solutions.html">Solutions</a>
+          <a href="/service/a">Backend A</a>
+          <a href="/service/b">Backend B</a>
+          <a href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
+        </nav>
       </section>
 
       <section class="panel">
diff --git a/proxy/html/solutions.html b/proxy/html/solutions.html
index a79858c..3add9bb 100644
--- a/proxy/html/solutions.html
+++ b/proxy/html/solutions.html
@@ -6,16 +6,17 @@
     <title>HTL Workshop Solutions</title>
     <style>
       :root {
-        --bg: #081825;
-        --panel: #10273d;
-        --panel-soft: #163450;
-        --text: #e9f2fb;
-        --muted: #b7cbdf;
-        --accent: #4ecdc4;
-        --easy: #59d68a;
-        --medium: #ffd166;
-        --hard: #ff7b72;
-        --expert: #6fb6ff;
+        --bg: #f3f3f6;
+        --surface: #ffffff;
+        --text: #16161a;
+        --muted: #65656e;
+        --magenta: #e20074;
+        --magenta-soft: #fbe3f0;
+        --line: #e5e5ea;
+        --code-bg: #f4f4f7;
+        --code-line: #e2e2e8;
+        --radius: 16px;
+        --shadow: 0 1px 2px rgba(20, 20, 40, 0.04), 0 10px 30px rgba(20, 20, 40, 0.06);
       }
 
       * {
@@ -24,62 +25,94 @@
 
       body {
         margin: 0;
-        font-family: "Fira Sans", "Segoe UI", sans-serif;
+        font-family: "TeleNeo", "Segoe UI", system-ui, -apple-system, sans-serif;
         color: var(--text);
-        background:
-          radial-gradient(circle at 100% 0%, #1f4060 0%, transparent 45%),
-          radial-gradient(circle at 0% 100%, #14324a 0%, transparent 35%),
-          var(--bg);
+        background: var(--bg);
         min-height: 100vh;
-        padding: 1.2rem;
+        padding: 2.2rem 1.2rem 3rem;
+        line-height: 1.55;
       }
 
       main {
         width: min(1150px, 100%);
         margin: 0 auto;
         display: grid;
-        gap: 1rem;
+        gap: 1.25rem;
       }
 
       .panel {
-        background: var(--panel);
-        border: 1px solid #315678;
-        border-radius: 14px;
-        padding: 1.1rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
+        border-radius: var(--radius);
+        padding: 1.5rem 1.6rem;
+        box-shadow: var(--shadow);
+      }
+
+      .hero {
+        position: relative;
+        overflow: hidden;
+      }
+
+      .hero::before {
+        content: "";
+        position: absolute;
+        top: 0;
+        bottom: 0;
+        left: 0;
+        width: 5px;
+        background: var(--magenta);
       }
 
       h1,
       h2,
       h3 {
         margin-top: 0;
+        font-weight: 800;
+        letter-spacing: -0.01em;
+        color: var(--text);
+      }
+
+      h1 {
+        font-size: 1.95rem;
+      }
+
+      h2 {
+        font-size: 1.3rem;
       }
 
       p,
       li {
         color: var(--muted);
-        line-height: 1.5;
+        line-height: 1.55;
       }
 
       a {
-        color: var(--accent);
+        color: var(--magenta);
+        text-decoration: none;
+        font-weight: 600;
+      }
+
+      a:hover {
+        text-decoration: underline;
       }
 
       code {
         font-family: "JetBrains Mono", "Fira Code", "Consolas", "Liberation Mono", monospace;
-        font-size: 0.92em;
-        background: #0d1f31;
-        border: 1px solid #2d4f6e;
+        font-size: 0.9em;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
         border-radius: 6px;
         padding: 0.1rem 0.35rem;
+        color: #2a2a30;
       }
 
       pre {
-        background: #0b2133;
-        border: 1px solid #2b5578;
-        border-radius: 10px;
-        padding: 0.75rem 0.85rem;
+        background: var(--code-bg);
+        border: 1px solid var(--code-line);
+        border-radius: 12px;
+        padding: 0.9rem 1rem;
         overflow-x: auto;
-        margin: 0.65rem 0;
+        margin: 0.7rem 0 0;
       }
 
       pre code {
@@ -88,61 +121,110 @@
         border: 0;
         border-radius: 0;
         padding: 0;
-        font-size: 0.92rem;
-        line-height: 1.45;
+        font-size: 0.88rem;
+        line-height: 1.5;
         white-space: pre;
+        color: #2a2a30;
       }
 
-      .top-links {
+      .brand {
+        display: flex;
+        align-items: center;
+        gap: 0.65rem;
+        margin-bottom: 1rem;
+      }
+
+      .tmark {
+        display: inline-flex;
+        align-items: center;
+        gap: 3px;
+      }
+
+      .tmark b {
+        font-size: 1.55rem;
+        font-weight: 800;
+        color: var(--magenta);
+        margin: 0 1px;
+        line-height: 1;
+      }
+
+      .brand span {
+        font-size: 0.82rem;
+        font-weight: 700;
+        letter-spacing: 0.12em;
+        text-transform: uppercase;
+        color: var(--muted);
+      }
+
+      .nav {
         display: flex;
         flex-wrap: wrap;
         gap: 0.5rem;
+        margin-top: 1.2rem;
       }
 
-      .pill {
-        display: inline-block;
+      .nav a {
         text-decoration: none;
-        background: #11314b;
-        border: 1px solid #2a5d84;
+        color: var(--text);
+        font-weight: 600;
+        font-size: 0.92rem;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 999px;
-        padding: 0.35rem 0.75rem;
+        padding: 0.45rem 0.95rem;
+        transition:
+          color 0.15s ease,
+          border-color 0.15s ease;
+      }
+
+      .nav a:hover {
+        border-color: var(--magenta);
+        color: var(--magenta);
+        text-decoration: none;
       }
 
       .badge {
         display: inline-block;
         border-radius: 999px;
-        padding: 0.15rem 0.5rem;
-        font-size: 0.8rem;
+        padding: 0.2rem 0.6rem;
+        font-size: 0.7rem;
         font-weight: 700;
-        margin-bottom: 0.45rem;
+        letter-spacing: 0.05em;
+        text-transform: uppercase;
       }
 
       .easy {
-        color: #08210f;
-        background: var(--easy);
+        color: #245c00;
+        background: #e4f3d6;
       }
 
       .medium {
-        color: #312200;
-        background: var(--medium);
+        color: #7a4d00;
+        background: #fdeecb;
       }
 
       .hard {
-        color: #3b0905;
-        background: var(--hard);
+        color: #8a0010;
+        background: #fbdcdc;
       }
 
       .expert {
-        color: #031c37;
-        background: var(--expert);
+        color: #004b66;
+        background: #d6eef7;
       }
 
       details {
-        background: var(--panel-soft);
-        border: 1px solid #2d5577;
+        background: var(--surface);
+        border: 1px solid var(--line);
         border-radius: 12px;
-        padding: 0.75rem 0.85rem;
-        margin-bottom: 0.7rem;
+        padding: 1rem 1.15rem;
+        margin-bottom: 0.8rem;
+        transition: border-color 0.15s ease;
+      }
+
+      details[open] {
+        border-color: #d8d8df;
+        box-shadow: var(--shadow);
       }
 
       details:last-child {
@@ -152,29 +234,55 @@
       summary {
         cursor: pointer;
         font-weight: 700;
+        color: var(--text);
+        list-style: none;
+        display: flex;
+        align-items: center;
+        gap: 0.6rem;
+      }
+
+      summary::-webkit-details-marker {
+        display: none;
+      }
+
+      summary::after {
+        content: "+";
+        margin-left: auto;
+        color: var(--magenta);
+        font-weight: 800;
+        font-size: 1.15rem;
+        line-height: 1;
+      }
+
+      details[open] summary::after {
+        content: "\2013";
       }
 
       .kw {
-        color: #e9f2fb;
+        color: var(--text);
         font-weight: 700;
       }
     </style>
   </head>
   <body>
     <main>
-      <section class="panel">
+      <section class="panel hero">
+        <div class="brand">
+          <span class="tmark"><b>T</b></span>
+          <span>Telekom Security</span>
+        </div>
         <h1>Solutions Board (detailliert)</h1>
         <p>Hier stehen absichtlich konkrete Musterloesungen mit Snippets, Checks und typischen Stolperfallen.</p>
         <p><span class="kw">Workflow:</span> Nach jeder Konfig-Aenderung mindestens <code>./scripts/lab.sh proxy-reload</code>, bei Compose-Aenderungen <code>./scripts/lab.sh redeploy</code>.</p>
-        <div class="top-links">
-          <a class="pill" href="/">Startseite</a>
-          <a class="pill" href="/challenges.html">Challenges</a>
-          <a class="pill" href="/hints.html">Hints</a>
-          <a class="pill" href="/solutions.html">Solutions</a>
-          <a class="pill" href="/service/a">Backend A</a>
-          <a class="pill" href="/service/b">Backend B</a>
-          <a class="pill" href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
-        </div>
+        <nav class="nav">
+          <a href="/">Startseite</a>
+          <a href="/challenges.html">Challenges</a>
+          <a href="/hints.html">Hints</a>
+          <a href="/solutions.html">Solutions</a>
+          <a href="/service/a">Backend A</a>
+          <a href="/service/b">Backend B</a>
+          <a href="/challenges.html#challenge-2-backend-c">Backend C (ab C2)</a>
+        </nav>
       </section>
 
       <section class="panel">
