body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(to right, #396b42, #194624, #1d4526);
  color: #fff;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.container {
  max-width: 400px;
  width: 90%;
  background: #1f1f2e;
  padding: 30px;
  border-radius: 10px;
  text-align: center;
  box-shadow: 0 0 15px rgba(244, 1, 37, 0.4);
}

h1 {
  color: #00ffc8;
  margin-bottom: 20px;
}

input, button {
  padding: 10px;
  margin: 10px 5px;
  border: none;
  border-radius: 5px;
  font-size: 16px;
  width: 90%;
}

button {
  background: #ff0000;
  color: #000;
  font-weight: bold;
  cursor: pointer;
  transition: 0.3s;
}

button:hover {
  background: #00ccaa;
}

#output {
  margin-top: 20px;
}

#strengthBar {
  width: 100%;
  height: 20px;
  background: #444;
  border-radius: 10px;
  margin: 10px auto;
  overflow: hidden;
}

#strength {
  height: 100%;
  width: 0%;
  background: limegreen;
  transition: width 0.3s;
}

.btn-group {
  display: flex;
  justify-content: space-around;
  margin-top: 10px;
}

.hidden {
  display: none;
}

#successMessage {
  color: #00ffc8;
  font-weight: bold;
  margin-top: 15px;
}