diff --git a/index.html b/index.html
index c683354..2771445 100644
--- a/index.html
+++ b/index.html
@@ -9,11 +9,17 @@
 body{font:17px/1.5 -apple-system,BlinkMacSystemFont,"Segoe UI",Inter,system-ui,sans-serif;background:#f0f2f5;color:#0F1218;min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:24px}
 .card{background:#fff;border-radius:20px;padding:48px;max-width:520px;width:100%;box-shadow:0 4px 24px rgba(0,0,0,.06)}
 h1{font-size:28px;font-weight:800;margin-bottom:8px}
-.sub{color:#5B6573;font-size:15px;margin-bottom:32px}
-label{display:block;font-weight:600;font-size:15px;margin-bottom:8px}
-input[type=number]{width:100%;padding:16px 20px;font-size:24px;font-weight:700;border:2px solid #d0d5dd;border-radius:12px;outline:none;transition:.15s;text-align:center}
-input:focus{border-color:#0F1218}
-input::placeholder{font-weight:400;color:#9aa3b2;font-size:17px}
+.sub{color:#5B6573;font-size:15px;margin-bottom:24px}
+.settings{background:#f6f8fa;border-radius:12px;padding:20px;margin-bottom:24px}
+.settings-row{display:flex;gap:12px;margin-bottom:12px}
+.settings-row:last-child{margin-bottom:0}
+.settings-row label{flex:1;font-size:14px;font-weight:600;color:#5B6573}
+.settings-row input{width:100%;padding:10px 14px;font-size:16px;font-weight:600;border:2px solid #d0d5dd;border-radius:8px;outline:none;text-align:center;transition:.15s}
+.settings-row input:focus{border-color:#0F1218}
+label[for=port]{display:block;font-weight:600;font-size:15px;margin-bottom:8px}
+input#port{width:100%;padding:16px 20px;font-size:24px;font-weight:700;border:2px solid #d0d5dd;border-radius:12px;outline:none;transition:.15s;text-align:center}
+input#port:focus{border-color:#0F1218}
+input#port::placeholder{font-weight:400;color:#9aa3b2;font-size:17px}
 button{width:100%;padding:16px;background:#0F1218;color:#fff;border:none;border-radius:12px;font-size:18px;font-weight:700;cursor:pointer;margin-top:16px;transition:.15s}
 button:hover{background:#2a2f3a}
 button:active{transform:scale(.98)}
@@ -33,16 +39,23 @@ button:active{transform:scale(.98)}
 .history-item .h-result{color:#0088cc;font-weight:600}
 .history-item .h-copy{color:#9aa3b2;font-size:13px;cursor:pointer;padding:4px 8px;border-radius:4px}
 .history-item .h-copy:hover{background:#d0d5dd;color:#0F1218}
-@media(max-width:480px){.card{padding:24px}h1{font-size:24px}input[type=number]{font-size:20px}}
+@media(max-width:480px){.card{padding:24px}.settings-row{flex-direction:column;gap:8px}h1{font-size:24px}input#port{font-size:20px}}
 </style>
 </head>
 <body>
 <div class="card">
   <h1>🔢 Кассеты и порты</h1>
-  <p class="sub">84 кассеты × 16 портов = 1–1344</p>
+  <p class="sub" id="subtitle">84 кассеты × 16 портов = 1–1344</p>
+
+  <div class="settings">
+    <div class="settings-row">
+      <label>Кассет <input type="number" id="cassettes" min="1" max="999" onchange="applySettings()"></label>
+      <label>Портов на кассете <input type="number" id="perPort" min="1" max="999" onchange="applySettings()"></label>
+    </div>
+  </div>
 
   <label for="port">Введи номер порта</label>
-  <input type="number" id="port" min="1" max="1344" placeholder="например, 699" autofocus>
+  <input type="number" id="port" min="1" placeholder="например, 699" autofocus>
   <div class="error" id="error">Введи число от 1 до 1344</div>
   <button onclick="calc()">Рассчитать</button>
 
@@ -58,13 +71,41 @@ button:active{transform:scale(.98)}
 </div>
 
 <script>
-const PORTS_PER_CASSETTE = 16;
-const TOTAL_CASSETTES = 84;
-const TOTAL_PORTS = TOTAL_CASSETTES * PORTS_PER_CASSETTE;
 const MAX_HISTORY = 50;
-
+let PORTS_PER_CASSETTE = 16;
+let TOTAL_CASSETTES = 84;
+let TOTAL_PORTS = TOTAL_CASSETTES * PORTS_PER_CASSETTE;
 let history = JSON.parse(localStorage.getItem('portHistory')||'[]');
 
+function loadSettings(){
+  const c=localStorage.getItem('pcCassettes');
+  const p=localStorage.getItem('pcPerPort');
+  if(c)document.getElementById('cassettes').value=TOTAL_CASSETTES=parseInt(c);
+  if(p)document.getElementById('perPort').value=PORTS_PER_CASSETTE=parseInt(p);
+  TOTAL_PORTS=TOTAL_CASSETTES*PORTS_PER_CASSETTE;
+}
+function saveSettings(){
+  localStorage.setItem('pcCassettes',TOTAL_CASSETTES);
+  localStorage.setItem('pcPerPort',PORTS_PER_CASSETTE);
+}
+function updateUI(){
+  document.getElementById('port').max=TOTAL_PORTS;
+  document.getElementById('port').placeholder=`1–${TOTAL_PORTS}`;
+  document.getElementById('subtitle').textContent=`${TOTAL_CASSETTES} кассет${TOTAL_CASSETTES%10===1?'а':''} × ${PORTS_PER_CASSETTE} портов = 1–${TOTAL_PORTS}`;
+}
+function applySettings(){
+  const c=parseInt(document.getElementById('cassettes').value);
+  const p=parseInt(document.getElementById('perPort').value);
+  if(!c||c<1)return;
+  if(!p||p<1)return;
+  TOTAL_CASSETTES=c;
+  PORTS_PER_CASSETTE=p;
+  TOTAL_PORTS=TOTAL_CASSETTES*PORTS_PER_CASSETTE;
+  saveSettings();
+  updateUI();
+  document.getElementById('result').classList.remove('show');
+}
+
 function calc(){
   const input=document.getElementById('port');
   const error=document.getElementById('error');
@@ -77,6 +118,7 @@ function calc(){
   result.classList.remove('show');
 
   if(!val||val<1||val>TOTAL_PORTS){
+    error.textContent=`Введи число от 1 до ${TOTAL_PORTS}`;
     error.classList.add('show');
     return;
   }
@@ -100,7 +142,6 @@ function addHistory(portNum,cassette,port,firstPort,lastPort){
   localStorage.setItem('portHistory',JSON.stringify(history));
   renderHistory();
 }
-
 function renderHistory(){
   const el=document.getElementById('history');
   const list=document.getElementById('historyList');
@@ -114,12 +155,10 @@ function renderHistory(){
     </div>
   `).join('');
 }
-
 function useHistory(i){
   document.getElementById('port').value=history[i].portNum;
   calc();
 }
-
 function copyResult(i){
   const h=history[i];
   const text=`${h.portNum} → ${h.cassette} кассета — ${h.port} порт`;
@@ -127,6 +166,8 @@ function copyResult(i){
 }
 
 document.getElementById('port').addEventListener('keydown',e=>{if(e.key==='Enter')calc()});
+loadSettings();
+updateUI();
 renderHistory();
 </script>
 </body>
