header {
    background-color: #151fb0;
    color: white;
    text-align: center;
    padding: 10px;
    top: 0;
    z-index: 1000;
    position: sticky;
}

header h1 {
    margin-top: 0;
}

nav ul {
    list-style-type: none;
    padding: 0;
    display: flex;
    justify-content: center;
    gap: 25px;
}

nav a {
    text-decoration: none;
    color: white;
    font-weight: bold;
    padding: 5px;
}

nav a:hover {
    background-color: rgb(186, 186, 255);
    color: #0c1154;
    padding: 5px;
    border-radius: 5px;
}

/* Centrar el contenido principal (form) y mantener header sticky */
main {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: calc(100vh - 64px);
  padding: 24px;
  box-sizing: border-box;
}

body {
      font-family: Arial, sans-serif;
      background: #f2f2f2;
      margin: 0;
      color: #222;
      -webkit-font-smoothing: antialiased;
    }

    form {
      background: white;
      padding: 25px;
      border-radius: 10px;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
      width: 100%;
      max-width: 420px;
      margin: 0 auto;
    }

    h2 {
      text-align: center;
      margin-bottom: 20px;
      color: #333;
    }

    label {
      font-weight: bold;
      font-size: 14px;
      display: block;
      margin-top: 10px;
    }

    input, select {
      width: 100%;
      padding: 10px;
      margin-top: 5px;
      border: 1px solid #ccc;
      border-radius: 6px;
      box-sizing: border-box;
    }

    button {
      width: 100%;
      padding: 10px;
      background: #007bff;
      border: none;
      color: white;
      border-radius: 6px;
      cursor: pointer;
      font-size: 16px;
      margin-top: 15px;
    }

    button:hover {
      background: #0056b3;
    }

    .error {
      color: red;
      font-size: 13px;
      margin-top: 10px;
    }