body {
  background: #121212;
  color: #eee;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  padding: 20px;
  box-sizing: border-box;
}

.container {
  background: #1e1e1e;
  padding: 25px 20px;
  border-radius: 10px;
  width: 100%;
  max-width: 380px;
  box-shadow: 0 0 15px #00c6ffaa;
  text-align: center;
}

h2 {
  margin-bottom: 20px;
  font-size: 1.5em;
}

.password-label {
  display: block;
  text-align: left;
  margin-bottom: 8px;
  font-weight: 600;
  font-size: 14px;
}

.input-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}

.input-wrapper input {
  flex: 1 1 100%;
  padding: 12px 15px;
  font-size: 16px;
  border-radius: 6px;
  border: 1px solid #444;
  background: #222;
  color: #eee;
  outline: none;
  box-sizing: border-box;
}

.input-wrapper input:focus {
  border-color: #00c6ff;
}

.input-wrapper button {
  margin-top: 10px;
  width: 100%;
  background: #333;
  border: none;
  color: #ccc;
  font-size: 16px;
  cursor: pointer;
  padding: 10px;
  border-radius: 6px;
  transition: background 0.3s, color 0.3s;
}

.input-wrapper button:hover {
  background: #00c6ff;
  color: #121212;
}

#strength-text {
  margin-top: 15px;
  font-weight: 600;
}

.strength-bar {
  background: #444;
  height: 8px;
  border-radius: 4px;
  margin: 10px 0 20px 0;
  overflow: hidden;
}

#strength-bar-fill {
  height: 100%;
  width: 0%;
  background: red;
  border-radius: 4px;
  transition: width 0.3s ease-in-out, background-color 0.3s ease-in-out;
}

.criteria-list {
  list-style: none;
  padding: 0;
  font-size: 14px;
  text-align: left;
}

.criteria-list li {
  margin: 6px 0;
  padding-left: 20px;
  position: relative;
}

.criteria-list li::before {
  content: "✗";
  position: absolute;
  left: 0;
  color: #ff4444;
  font-weight: bold;
}

.criteria-list li.valid::before {
  content: "✓";
  color: #4caf50;
}

/* --- Mobile Specific Styles --- */
@media (max-width: 480px) {
  h2 {
    font-size: 1.3em;
  }

  .container {
    padding: 20px 15px;
  }

  .input-wrapper {
    flex-direction: column;
    align-items: stretch;
  }

  .input-wrapper input,
  .input-wrapper button {
    width: 100%;
  }
}