diff --git a/frontend/src/App.jsx b/frontend/src/App.jsx
index 170daf1..6291f08 100644
--- a/frontend/src/App.jsx
+++ b/frontend/src/App.jsx
@@ -1,6 +1,7 @@
 import { useState, useEffect, useRef, useCallback } from 'react';
 import { api, S } from './lib.js';
 import { TOOLS, getGroupedTools } from './toolRegistry.js';
+import { HomeIcon, AppsIcon, AdminIcon, MoreIcon, UserIcon, LogOutIcon, ChevronIcon, UpdateIcon } from './icons.jsx';
 
 const ICONS = ['🔗','🌐','📊','📁','🛠','📧','🗓','💾','🖥','📡','🔒','📖','🎯','⚡','🏠','🔧','📱','🎮','🚀','💡'];
 
@@ -136,22 +137,25 @@ function UpdateModal({ data, onClose }) {
 function Sidebar({ active, setActive, user, onLogout, updateInfo, onUpdateClick }) {
   const [appsOpen, setAppsOpen] = useState(true);
 
-  const NavBtn = ({ item, sub=false }) => (
-    <button onClick={()=>setActive(item.id)} style={{
-      width:'100%', display:'flex', alignItems:'center', gap:9,
-      padding: '8px 12px 8px 12px',
-      borderRadius:7, border:'none',
-      background: active===item.id ? 'linear-gradient(90deg,rgba(78,205,196,0.14),rgba(78,205,196,0.02))' : 'transparent',
-      color: active===item.id ? '#4ecdc4' : 'rgba(255,255,255,0.6)',
-      cursor:'pointer', fontSize:12,
-      fontFamily:"'Space Mono',monospace", textAlign:'left', marginBottom:1,
-      borderLeft: active===item.id ? '2px solid #4ecdc4' : '2px solid transparent',
-    }}>
-      {sub && <span style={{ width:1, alignSelf:'stretch', background:'rgba(255,255,255,0.08)', marginRight:4, flexShrink:0 }}/>}
-      <span style={{ fontSize:13 }}>{item.icon}</span>
-      <span style={{ flex:1 }}>{item.label}</span>
-    </button>
-  );
+  const NavBtn = ({ item, sub=false }) => {
+    const ic = active===item.id ? '#4ecdc4' : 'rgba(255,255,255,0.55)';
+    return (
+      <button onClick={()=>setActive(item.id)} style={{
+        width:'100%', display:'flex', alignItems:'center', gap:9,
+        padding:'8px 12px', borderRadius:7, border:'none',
+        background: active===item.id ? 'linear-gradient(90deg,rgba(78,205,196,0.14),rgba(78,205,196,0.02))' : 'transparent',
+        cursor:'pointer', fontSize:12,
+        fontFamily:"'Space Mono',monospace", textAlign:'left', marginBottom:1,
+        borderLeft: active===item.id ? '2px solid #4ecdc4' : '2px solid transparent',
+      }}>
+        {sub && <span style={{ width:1, alignSelf:'stretch', background:'rgba(255,255,255,0.08)', marginRight:3, flexShrink:0 }}/>}
+        <span style={{ display:'flex', alignItems:'center', width:18, justifyContent:'center', flexShrink:0 }}>
+          {item.Icon ? <item.Icon size={15} color={ic}/> : <span style={{color:ic,fontSize:13}}>{item.icon}</span>}
+        </span>
+        <span style={{ flex:1, color:ic }}>{item.label}</span>
+      </button>
+    );
+  };
 
   return (
     <aside style={{ width:210, minHeight:'100vh', background:'#0d0d0f',
@@ -169,7 +173,7 @@ function Sidebar({ active, setActive, user, onLogout, updateInfo, onUpdateClick
         </div>
       </div>
       <nav style={{ flex:1, padding:'0 8px' }}>
-        <NavBtn item={{ id:'dashboard', icon:'⬡', label:'Dashboard' }} />
+        <NavBtn item={{ id:'dashboard', Icon:HomeIcon, label:'Dashboard' }} />
 
         {/* Apps Sektion mit Gruppenüberschriften */}
         <button onClick={()=>setAppsOpen(v=>!v)} style={{
@@ -191,7 +195,7 @@ function Sidebar({ active, setActive, user, onLogout, updateInfo, onUpdateClick
           </div>
         ))}
 
-        {user?.role==='admin' && <NavBtn item={{ id:'admin', icon:'⚙', label:'Admin' }} />}
+        {user?.role==='admin' && <NavBtn item={{ id:'admin', icon:'⚙️', label:'Admin' }} />}
       </nav>
       {updateInfo?.hasUpdate && (
         <button onClick={onUpdateClick} style={{
@@ -207,7 +211,7 @@ function Sidebar({ active, setActive, user, onLogout, updateInfo, onUpdateClick
       <div style={{ padding:'10px 12px 16px', borderTop:'1px solid rgba(255,255,255,0.06)' }}>
         <div style={{ display:'flex', alignItems:'center', gap:8, marginBottom:8 }}>
           <div style={{ width:24, height:24, borderRadius:'50%', background:'linear-gradient(135deg,#ff6b9d,#4ecdc4)',
-            display:'flex', alignItems:'center', justifyContent:'center', fontSize:10 }}>👤</div>
+            display:'flex', alignItems:'center', justifyContent:'center' }}><UserIcon size={14} color="#0d0d0f"/></div>
           <div style={{ color:'#fff', fontSize:11, fontFamily:'monospace' }}>{user?.username}</div>
         </div>
         <button onClick={onLogout} style={{ ...S.btn('#ff6b9d',true), width:'100%', textAlign:'center' }}>Ausloggen</button>
@@ -225,7 +229,7 @@ function BottomNav({ active, setActive, user, onLogout, updateInfo, onUpdateClic
   const MI = ({icon, label, onClick, color='#fff'}) => (
     <button onClick={onClick} style={{ width:'100%', padding:'11px 20px', background:'transparent',
       border:'none', display:'flex', alignItems:'center', gap:10, cursor:'pointer' }}>
-      <span style={{fontSize:17, flexShrink:0, width:22, textAlign:'center', display:'inline-block', color:'rgba(255,255,255,0.85)'}}>{icon}</span>
+      <span style={{fontSize:17, flexShrink:0, width:22, textAlign:'center', display:'inline-block', }}>{icon}</span>
       <span style={{color, fontFamily:'monospace', fontSize:13}}>{label}</span>
     </button>
   );
@@ -246,10 +250,10 @@ function BottomNav({ active, setActive, user, onLogout, updateInfo, onUpdateClic
   );
 
   const mainNav = [
-    { id:'dashboard', icon:'⬡', label:'Home' },
-    { id:'_apps',     icon:'◫', label:'Apps'  },
-    ...(user?.role==='admin' ? [{ id:'admin', icon:'⚙', label:'Admin' }] : []),
-    { id:'_mehr',     icon:'⋯', label:'Mehr'  },
+    { id:'dashboard', Icon:HomeIcon,  label:'Home' },
+    { id:'_apps',     Icon:AppsIcon,  label:'Apps'  },
+    ...(user?.role==='admin' ? [{ id:'admin', Icon:AdminIcon, label:'Admin' }] : []),
+    { id:'_mehr',     Icon:MoreIcon,  label:'Mehr'  },
   ];
 
   return (
@@ -262,7 +266,7 @@ function BottomNav({ active, setActive, user, onLogout, updateInfo, onUpdateClic
               <div style={{ color:'rgba(255,255,255,0.28)', fontSize:9, fontFamily:'monospace',
                 letterSpacing:2, padding:'12px 20px 5px' }}>{group.toUpperCase()}</div>
               {tools.map(t => (
-                <MI key={t.id} icon={t.icon} label={t.label}
+                <MI key={t.id} Icon={t.Icon} label={t.label}
                   onClick={() => { setActive(t.id); setAppsOpen(false); }} />
               ))}
             </div>
@@ -272,10 +276,10 @@ function BottomNav({ active, setActive, user, onLogout, updateInfo, onUpdateClic
 
       {/* Mehr Sheet */}
       <Sheet open={menuOpen} onClose={()=>setMenuOpen(false)}>
-        {updateInfo?.hasUpdate && <MI icon="📦" label={`Update: ${updateInfo.latestVersion}`} onClick={()=>{setMenuOpen(false);onUpdateClick();}} color="#ffe66d"/>}
+        {updateInfo?.hasUpdate && <MI Icon={UpdateIcon} label={`Update: ${updateInfo.latestVersion}`} onClick={()=>{setMenuOpen(false);onUpdateClick();}} color="#ffe66d"/>}
         <div style={{height:1, background:'rgba(255,255,255,0.08)', margin:'4px 0'}}/>
-        <MI icon="👤" label={user?.username||''} onClick={()=>{}} color="rgba(255,255,255,0.35)"/>
-        <MI icon="🚪" label="Ausloggen" onClick={()=>{onLogout();setMenuOpen(false);}} color="#ff6b9d"/>
+        <MI Icon={UserIcon} label={user?.username||''} onClick={()=>{}} color="rgba(255,255,255,0.35)"/>
+        <MI Icon={LogOutIcon} label="Ausloggen" onClick={()=>{onLogout();setMenuOpen(false);}} color="#ff6b9d"/>
       </Sheet>
 
       {/* Bottom Bar */}
@@ -301,7 +305,7 @@ function BottomNav({ active, setActive, user, onLogout, updateInfo, onUpdateClic
                     width:8, height:8, borderRadius:'50%', background:'#ffe66d',
                     boxShadow:'0 0 6px #ffe66d', display:'inline-block' }} />
                 )}
-                <span style={{ fontSize:20, lineHeight:1 }}>{item.icon}</span>
+                <item.Icon size={20} color={isActive ? '#4ecdc4' : 'rgba(255,255,255,0.45)'}/>
                 <span style={{ fontSize:9, fontFamily:'monospace', letterSpacing:0.3,
                   color: isActive ? '#4ecdc4' : 'rgba(255,255,255,0.4)' }}>{item.label}</span>
                 {isActive && !isApps && !isMehr && (
diff --git a/frontend/src/icons.jsx b/frontend/src/icons.jsx
new file mode 100644
index 0000000..f3d862f
--- /dev/null
+++ b/frontend/src/icons.jsx
@@ -0,0 +1,139 @@
+// ── Icon Library – stroke-basierte SVG Icons ──────────────────────────────────
+// Verwendung: <Icon name="home" size={20} color="#4ecdc4" />
+// Oder direkt: <HomeIcon size={20} color="#fff" />
+
+const base = (path, size, color, sw = 1.75) => (
+  <svg width={size} height={size} viewBox="0 0 24 24" fill="none"
+    stroke={color} strokeWidth={sw} strokeLinecap="round" strokeLinejoin="round">
+    {path}
+  </svg>
+);
+
+export const HomeIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M3 9.5L12 3l9 6.5V20a1 1 0 0 1-1 1H5a1 1 0 0 1-1-1V9.5z"/>
+  <path d="M9 21V12h6v9"/>
+</>, size, color, sw);
+
+export const AppsIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <rect x="3" y="3" width="7" height="7" rx="1"/>
+  <rect x="14" y="3" width="7" height="7" rx="1"/>
+  <rect x="3" y="14" width="7" height="7" rx="1"/>
+  <rect x="14" y="14" width="7" height="7" rx="1"/>
+</>, size, color, sw);
+
+export const CalculatorIcon = ({size=20,color='currentColor',sw}) => base(<>
+  <rect x="4" y="2" width="16" height="20" rx="2"/>
+  <line x1="8" y1="7" x2="16" y2="7"/>
+  <line x1="8" y1="12" x2="10" y2="12"/>
+  <line x1="14" y1="12" x2="16" y2="12"/>
+  <line x1="8" y1="17" x2="10" y2="17"/>
+  <line x1="14" y1="17" x2="16" y2="17"/>
+</>, size, color, sw);
+
+export const ArchiveIcon  = ({size=20,color='currentColor',sw}) => base(<>
+  <rect x="2" y="3" width="20" height="4" rx="1"/>
+  <path d="M4 7v13a1 1 0 0 0 1 1h14a1 1 0 0 0 1-1V7"/>
+  <line x1="9" y1="12" x2="15" y2="12"/>
+</>, size, color, sw);
+
+export const AdminIcon    = ({size=20,color='currentColor',sw}) => base(<>
+  <circle cx="12" cy="12" r="3"/>
+  <path d="M12 2v2M12 20v2M4.22 4.22l1.42 1.42M18.36 18.36l1.42 1.42M2 12h2M20 12h2M4.22 19.78l1.42-1.42M18.36 5.64l1.42-1.42"/>
+</>, size, color, sw);
+
+export const MoreIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <circle cx="5" cy="12" r="1.2" fill={color}/>
+  <circle cx="12" cy="12" r="1.2" fill={color}/>
+  <circle cx="19" cy="12" r="1.2" fill={color}/>
+</>, size, color, sw);
+
+export const UserIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <circle cx="12" cy="8" r="4"/>
+  <path d="M4 20c0-4 3.6-7 8-7s8 3 8 7"/>
+</>, size, color, sw);
+
+export const LogOutIcon   = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4"/>
+  <polyline points="16 17 21 12 16 7"/>
+  <line x1="21" y1="12" x2="9" y2="12"/>
+</>, size, color, sw);
+
+export const SearchIcon   = ({size=20,color='currentColor',sw}) => base(<>
+  <circle cx="11" cy="11" r="7"/>
+  <line x1="21" y1="21" x2="16.65" y2="16.65"/>
+</>, size, color, sw);
+
+export const PlusIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <line x1="12" y1="5" x2="12" y2="19"/>
+  <line x1="5" y1="12" x2="19" y2="12"/>
+</>, size, color, sw);
+
+export const XIcon        = ({size=20,color='currentColor',sw}) => base(<>
+  <line x1="18" y1="6" x2="6" y2="18"/>
+  <line x1="6" y1="6" x2="18" y2="18"/>
+</>, size, color, sw);
+
+export const CheckIcon    = ({size=20,color='currentColor',sw}) => base(<>
+  <polyline points="20 6 9 17 4 12"/>
+</>, size, color, sw);
+
+export const EditIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"/>
+  <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"/>
+</>, size, color, sw);
+
+export const TrashIcon    = ({size=20,color='currentColor',sw}) => base(<>
+  <polyline points="3 6 5 6 21 6"/>
+  <path d="M19 6l-1 14a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2L5 6"/>
+  <path d="M10 11v6M14 11v6"/>
+  <path d="M9 6V4a1 1 0 0 1 1-1h4a1 1 0 0 1 1 1v2"/>
+</>, size, color, sw);
+
+export const DownloadIcon = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/>
+  <polyline points="7 10 12 15 17 10"/>
+  <line x1="12" y1="15" x2="12" y2="3"/>
+</>, size, color, sw);
+
+export const UploadIcon   = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/>
+  <polyline points="17 8 12 3 7 8"/>
+  <line x1="12" y1="3" x2="12" y2="15"/>
+</>, size, color, sw);
+
+export const UpdateIcon   = ({size=20,color='currentColor',sw}) => base(<>
+  <circle cx="12" cy="12" r="9"/>
+  <line x1="12" y1="8" x2="12" y2="12"/>
+  <line x1="12" y1="16" x2="12.01" y2="16"/>
+</>, size, color, sw);
+
+export const ChevronIcon  = ({size=20,color='currentColor',sw,dir='right'}) => base(<>
+  {dir==='right' && <polyline points="9 18 15 12 9 6"/>}
+  {dir==='down'  && <polyline points="6 9 12 15 18 9"/>}
+</>, size, color, sw);
+
+export const CameraIcon   = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M23 19a2 2 0 0 1-2 2H3a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h4l2-3h6l2 3h4a2 2 0 0 1 2 2z"/>
+  <circle cx="12" cy="13" r="4"/>
+</>, size, color, sw);
+
+export const KeyIcon      = ({size=20,color='currentColor',sw}) => base(<>
+  <circle cx="8" cy="12" r="5"/>
+  <path d="M13 12h8M17 10v4"/>
+</>, size, color, sw);
+
+export const DatabaseIcon = ({size=20,color='currentColor',sw}) => base(<>
+  <ellipse cx="12" cy="5" rx="9" ry="3"/>
+  <path d="M3 5v4c0 1.66 4.03 3 9 3s9-1.34 9-3V5"/>
+  <path d="M3 9v4c0 1.66 4.03 3 9 3s9-1.34 9-3V9"/>
+  <path d="M3 13v4c0 1.66 4.03 3 9 3s9-1.34 9-3v-4"/>
+</>, size, color, sw);
+
+export const LinkIcon     = ({size=20,color='currentColor',sw}) => base(<>
+  <path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"/>
+  <path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"/>
+</>, size, color, sw);
+
+export const ZapIcon      = ({size=20,color='currentColor',sw}) => base(<>
+  <polygon points="13 2 3 14 12 14 11 22 21 10 12 10 13 2"/>
+</>, size, color, sw);
diff --git a/frontend/src/toolRegistry.js b/frontend/src/toolRegistry.js
index a16d0fa..b84ce3b 100644
--- a/frontend/src/toolRegistry.js
+++ b/frontend/src/toolRegistry.js
@@ -1,17 +1,14 @@
 import Kalkulator3D, { SavedList } from './tools/kalkulator3d.jsx';
+import { CalculatorIcon, ArchiveIcon } from './icons.jsx';
 
 // ══════════════════════════════════════════════════════════════════════════════
 //  Tool-Registry
-//
-//  Neues Tool:
-//   1. backend/src/tools/<id>/routes.js  → automatisch geladen
-//   2. frontend/src/tools/<id>.jsx
-//   3. Hier eintragen, group = Bereichsüberschrift
+//  Neues Tool: id, icon (SVG-Komponente), label, navLabel, group, component
 // ══════════════════════════════════════════════════════════════════════════════
 export const TOOLS = [
   {
     id:        'kalkulator3d',
-    icon:      '◈',
+    Icon:      CalculatorIcon,
     label:     'Kostenrechner',
     navLabel:  'Kosten',
     group:     '3D-Druck',
@@ -19,16 +16,14 @@ export const TOOLS = [
   },
   {
     id:        'kalkulator3d-saved',
-    icon:      '◉',
+    Icon:      ArchiveIcon,
     label:     'Archiv',
     navLabel:  'Archiv',
     group:     '3D-Druck',
     component: SavedList,
   },
-  // { id:'newtool', icon:'◇', label:'Mein Tool', navLabel:'Tool', group:'Mein Bereich', component:MeinTool },
 ];
 
-// Werkzeug zum Gruppieren für Navigation
 export function getGroupedTools() {
   const groups = {};
   for (const t of TOOLS) {
@@ -36,5 +31,5 @@ export function getGroupedTools() {
     if (!groups[g]) groups[g] = [];
     groups[g].push(t);
   }
-  return Object.entries(groups); // [['3D-Druck', [...tools]], ...]
+  return Object.entries(groups);
 }