* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, sans-serif;
  background: #f5f5f5;
  color: #333;
}

.container {
  max-width: 480px;
  margin: 50px auto;
  background: #fff;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
  text-align: center;
}

.container h2 {
  color: #d32f2f;
  margin-bottom: 15px;
  font-size: 1.6rem;
}

.container form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 15px;
}

.container form input[type="number"] {
  padding: 12px;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: 8px;
  outline: none;
  transition: border-color 0.3s;
}

.container form input[type="number"]:focus {
  border-color: #d32f2f;
}

.container form button {
  background: #d32f2f;
  color: #fff;
  padding: 12px;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s;
}

.container form button:hover {
  background: #b71c1c;
}

.container .how-to-get-imei {
  margin: 15px 0;
  font-size: 0.95rem;
}

.container .how-to-get-imei a {
  color: #d32f2f;
  text-decoration: none;
  font-weight: 600;
}

.container .how-to-get-imei a:hover {
  text-decoration: underline;
}

.container .how-to-get-imei #imeiInfo {
  margin-top: 10px;
  text-align: left;
}

.container .how-to-get-imei #imeiInfo .imei-step {
  margin-bottom: 10px;
}

.container .how-to-get-imei #imeiInfo .imei-step h4 {
  font-size: 1rem;
  margin-bottom: 5px;
  color: #333;
}

.container .how-to-get-imei #imeiInfo .imei-step img {
  width: 100%;
  border-radius: 6px;
  border: 1px solid #ddd;
}

.container .result {
  margin-top: 15px;
  padding: 12px;
  font-weight: 600;
  border-radius: 8px;
}

.container .result.clean {
  color: #2e7d32;
  border: 1px solid #2e7d32;
  background: rgba(46, 125, 50, 0.08);
}

.container .result.bad {
  color: #c62828;
  border: 1px solid #c62828;
  background: rgba(198, 40, 40, 0.08);
}

.container .error {
  margin-top: 10px;
  color: #c62828;
  font-weight: 600;
}

.container .clean-image {
  margin-top: 10px;
}

.container .clean-image img {
  width: 80px;
  height: auto;
}

@media (max-width: 500px) {
  .container {
    margin: 20px;
    padding: 20px;
  }
}