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

/* Body Layout */
body {
  font-family: Arial, sans-serif;
  background-color: #f1f1f1;
  color: #333;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Navigation Bar */
nav {
  background-color: #222;
  padding: 1rem;
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

nav a {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
}

nav a:hover {
  text-decoration: underline;
}

/* Main Content */
main {
  flex: 1;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Heading */
main h1 {
  font-size: 2rem;
  margin-bottom: 2rem;
  text-align: center;
}

/* Form Container */
form {
  background-color: #fff;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  width: 100%;
  max-width: 400px;
}

/* Fieldset and Legend */
form fieldset {
  border: none;
  padding: 0;
  margin: 0 0 1.5rem 0;
}

form legend {
  font-weight: bold;
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

/* Labels and Inputs */
form label {
  display: block;
  margin-bottom: 1rem;
}

form input[type="text"] {
  width: 100%;
  padding: 0.75rem;
  border-radius: 6px;
  border: 1px solid #ccc;
  margin-top: 0.25rem;
  font-size: 1rem;
}

/* Submit Button */
form input[type="submit"] {
  background-color: #4CAF50;
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s ease;
  width: 100%;
}

form input[type="submit"]:hover {
  background-color: #388e3c;
}

/* Error Message */
main > div:last-child span {
  color: red;
  margin-top: 1rem;
  display: block;
  text-align: center;
}

/* Responsive Adjustments */
@media (max-width: 600px) {
  main h1 {
    font-size: 1.5rem;
  }

  form {
    padding: 1.5rem;
  }

  form input[type="submit"] {
    font-size: 0.95rem;
  }
}