diff --git a/index.html b/index.html
index 7384b32..c855d2b 100644
--- a/index.html
+++ b/index.html
@@ -12,11 +12,11 @@
 
     <form>
       <input
-        type="number"
+        type="text"
         id="taj"
+        oninput="restrictInput(this, 'number')"
+        maxlength="9"
         required
-        pattern="/^-?\d+\.?\d*$/"
-        onKeyPress="if(this.value.length==9) return false;"
       />
       <button type="button" onclick="checkTAJ()">Ellenőrzés</button>
     </form>
diff --git a/script.js b/script.js
index 1200fb0..38ed9c3 100644
--- a/script.js
+++ b/script.js
@@ -1,31 +1,28 @@
-function validateTAJ(taj) {
-  taj = taj.replace(/[^0-9]/g, '');
+// Input 0
+function restrictInput(input) {
+  input.value = input.value.replace(/[^0-9]/g, '').slice(0, 9);
+}
 
-  if (taj.length != 9) {
-    return false;
+function validateTAJ(a) {
+  a = a.replace(/[^0-9]/g, '');
+  if (9 != a.length) {
+    return !1;
   }
-
-  let sum = 0;
-  let num = '';
-
-  for (let i = 0; i < taj.length; i++) {
-    if (i <= 7) {
-      sum += (i + 1) % 2 == 0 ? parseInt(taj[i]) * 7 : parseInt(taj[i]) * 3;
-      num += taj[i];
-    }
+  for (var b = 0, d = '', c = 0; c < a.length; c++) {
+    7 >= c &&
+      ((b += 0 == (c + 1) % 2 ? 7 * parseInt(a[c]) : 3 * parseInt(a[c])),
+      (d += a[c]));
   }
-
-  num += sum % 10;
-  return taj == num;
+  return a == d + (b % 10);
 }
 
 function checkTAJ() {
-  const tajInput = document.querySelector('#taj');
-  const resultElement = document.querySelector('#result');
+  var a = document.querySelector('#taj'),
+    b = document.querySelector('#result');
 
-  validateTAJ(tajInput.value)
-    ? ((resultElement.textContent = 'A TAJ szám érvényes.'),
-      (resultElement.style.color = '#4CAF50'))
-    : ((resultElement.textContent = 'A TAJ szám érvénytelen.'),
-      (resultElement.style.color = '#FF5733'));
+  validateTAJ(a.value)
+    ? ((b.textContent = 'A TAJ sz\u00e1m \u00e9rv\u00e9nyes.'),
+      (b.style.color = '#4CAF50'))
+    : ((b.textContent = 'A TAJ sz\u00e1m \u00e9rv\u00e9nytelen.'),
+      (b.style.color = '#FF5733'));
 }
diff --git a/style.css b/style.css
index cdc8b7d..d44a429 100644
--- a/style.css
+++ b/style.css
@@ -3,18 +3,18 @@ body {
   background-color: #121212;
   color: #338ef7;
   text-align: center;
-  margin-top: 10%;
   font-size: 1.5rem;
+  margin: 10% auto;
+  width: 100%;
 }
 
 form {
-  width: 300px;
+  max-width: 300px;
   margin: 0 auto;
 }
 
 label,
 input {
-  display: block;
   margin: 10px 0;
   color: #338ef7;
   font-size: 2rem;