diff --git a/frontend/src/tools/devtools.jsx b/frontend/src/tools/devtools.jsx
index defccb6..bc28776 100644
--- a/frontend/src/tools/devtools.jsx
+++ b/frontend/src/tools/devtools.jsx
@@ -1001,13 +1001,24 @@ function TextDiff({ mobile }) {
             <div style={{display:'flex', alignItems:'center', gap:8, marginBottom:6}}>
               <span style={{color:'rgba(255,255,255,0.55)', fontFamily:'monospace', fontSize:10, flex:1}}>{label}</span>
               <label style={{...S.btn('#4ecdc4',false), fontSize:10, padding:'3px 10px', cursor:'pointer'}}>
-                📂 .txt laden
+                📂 Datei laden
                 <input type="file" accept=".txt,.md,.log,.csv,.json,.xml,.yaml,.yml,.js,.ts,.jsx,.tsx,.py,.php,.sh,.env"
                   style={{display:'none'}} onChange={e=>loadFile(e,setter)}/>
               </label>
             </div>
-            <textarea style={ta} value={val} placeholder="Text hier einfügen…"
-              onChange={e=>{ setter(e.target.value); setDiff(null); }}/>
+            {/* Textarea mit Zeilennummern */}
+            <div style={{display:'flex', borderRadius:6, overflow:'hidden', border:'1px solid rgba(255,255,255,0.1)', background:'rgba(255,255,255,0.04)'}}>
+              <div style={{
+                padding:'7px 6px', minWidth:36, textAlign:'right', userSelect:'none',
+                fontFamily:"'Courier New',monospace", fontSize:12, lineHeight:'1.6',
+                color:'rgba(255,255,255,0.25)', background:'rgba(0,0,0,0.2)',
+                borderRight:'1px solid rgba(255,255,255,0.07)', whiteSpace:'pre'}}>
+                {(val||' ').split('\n').map((_,i)=>i+1).join('\n')}
+              </div>
+              <textarea style={{...ta, border:'none', borderRadius:0, background:'transparent', flex:1, resize:'vertical'}}
+                value={val} placeholder="Text hier einfügen…"
+                onChange={e=>{ setter(e.target.value); setDiff(null); }}/>
+            </div>
           </div>
         ))}
       </div>
@@ -1036,21 +1047,35 @@ function TextDiff({ mobile }) {
           overflow:'auto', maxHeight:480, background:'rgba(0,0,0,0.2)'}}>
           <table style={{width:'100%', borderCollapse:'collapse', fontFamily:"'Courier New',monospace", fontSize:12}}>
             <tbody>
-              {diff.map((d, i) => (
-                <tr key={i} style={{
-                  background: d.type==='add' ? 'rgba(78,205,196,0.1)' : d.type==='del' ? 'rgba(255,107,157,0.1)' : 'transparent',
-                  borderBottom: '1px solid rgba(255,255,255,0.03)'}}>
-                  <td style={{width:24, textAlign:'center', padding:'2px 6px', userSelect:'none',
-                    color: d.type==='add'?'#4ecdc4': d.type==='del'?'#ff6b9d':'rgba(255,255,255,0.2)',
-                    fontWeight:700, fontSize:14, borderRight:'1px solid rgba(255,255,255,0.05)'}}>
-                    {d.type==='add'?'+': d.type==='del'?'−':''}
-                  </td>
-                  <td style={{padding:'3px 10px', whiteSpace:'pre-wrap', wordBreak:'break-all',
-                    color: d.type==='add'?'#a8f0eb': d.type==='del'?'#ffb3cc':'rgba(255,255,255,0.65)'}}>
-                    {d.text || ' '}
-                  </td>
-                </tr>
-              ))}
+              {(()=>{
+                let lnA=0, lnB=0;
+                return diff.map((d,i)=>{
+                  if (d.type==='del') lnA++;
+                  else if (d.type==='add') lnB++;
+                  else { lnA++; lnB++; }
+                  const ln = d.type==='add' ? lnB : lnA;
+                  return (
+                    <tr key={i} style={{
+                      background: d.type==='add'?'rgba(78,205,196,0.1)':d.type==='del'?'rgba(255,107,157,0.1)':'transparent',
+                      borderBottom:'1px solid rgba(255,255,255,0.03)'}}>
+                      <td style={{width:36,textAlign:'right',padding:'2px 8px',userSelect:'none',
+                        color:'rgba(255,255,255,0.2)',fontFamily:"'Courier New',monospace",fontSize:11,
+                        borderRight:'1px solid rgba(255,255,255,0.05)'}}>
+                        {ln}
+                      </td>
+                      <td style={{width:24,textAlign:'center',padding:'2px 6px',userSelect:'none',
+                        color:d.type==='add'?'#4ecdc4':d.type==='del'?'#ff6b9d':'rgba(255,255,255,0.2)',
+                        fontWeight:700,fontSize:14,borderRight:'1px solid rgba(255,255,255,0.05)'}}>
+                        {d.type==='add'?'+':d.type==='del'?'−':''}
+                      </td>
+                      <td style={{padding:'3px 10px',whiteSpace:'pre-wrap',wordBreak:'break-all',
+                        color:d.type==='add'?'#a8f0eb':d.type==='del'?'#ffb3cc':'rgba(255,255,255,0.65)'}}>
+                        {d.text||' '}
+                      </td>
+                    </tr>
+                  );
+                });
+              })()}
             </tbody>
           </table>
         </div>
@@ -1073,6 +1098,8 @@ function NetzwerkRechner({ mobile }) {
   // ── Geschwindigkeit ──
   const [speedVal, setSpeedVal] = useState('');
   const [speedUnit, setSpeedUnit] = useState('mbps');
+  const [customSize, setCustomSize] = useState('');
+  const [customSizeUnit, setCustomSizeUnit] = useState('mb');
 
   const SPEED_UNITS = [
     { id:'bps',   label:'bit/s',   toBps: 1 },
@@ -1239,6 +1266,22 @@ function NetzwerkRechner({ mobile }) {
                 {[['700 MB CD',700e6],['4,7 GB DVD',4.7e9],['25 GB Blu-ray',25e9],['50 GB Spiel',50e9],['100 GB',100e9]].map(([lbl,b])=>(
                   <NRow key={lbl} label={lbl} value={dlTime(speedBps,b)} muted/>
                 ))}
+                <div style={{borderTop:'1px solid rgba(255,255,255,0.07)',marginTop:8,paddingTop:8}}>
+                  <div style={{display:'flex',gap:8,alignItems:'center',flexWrap:'wrap',marginBottom:6}}>
+                    <span style={{color:'rgba(255,255,255,0.5)',fontFamily:'monospace',fontSize:11,minWidth:80}}>Eigene Größe</span>
+                    <input style={{...inp,width:90,flex:'none'}} type="number" min="0" placeholder="z.B. 8"
+                      value={customSize} onChange={e=>setCustomSize(e.target.value)}/>
+                    <select style={{...inp,width:70,flex:'none',cursor:'pointer'}} value={customSizeUnit} onChange={e=>setCustomSizeUnit(e.target.value)}>
+                      <option value="kb">kB</option>
+                      <option value="mb">MB</option>
+                      <option value="gb">GB</option>
+                      <option value="tb">TB</option>
+                    </select>
+                    {!!customSize && <span style={{color:'#4ecdc4',fontFamily:"'Courier New',monospace",fontSize:13,fontWeight:700}}>
+                      {dlTime(speedBps, parseFloat(customSize) * ({kb:1e3,mb:1e6,gb:1e9,tb:1e12}[customSizeUnit]||1e6))}
+                    </span>}
+                  </div>
+                </div>
               </div>
               <div style={{marginTop:10,padding:'8px 12px',borderRadius:7,
                 background:'rgba(255,255,255,0.02)',border:'1px solid rgba(255,255,255,0.06)'}}>