body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f5f7fa;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
}

.container {
    background: #fff;
    padding: 40px 30px;
    border-radius: 15px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
    width: 400px;
    max-width: 90%;
}

.container h2 {
    text-align: center;
    margin-bottom: 25px;
    color: #333;
}

form label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 600;
}

form input[type="text"],
form input[type="email"],
form input[type="password"] {
    width: 100%;
    padding: 10px 15px;
    margin-bottom: 20px;
    border: 1px solid #ccc;
    border-radius: 8px;
    box-sizing: border-box;
    transition: border-color 0.3s ease;
}

form input[type="text"]:focus,
form input[type="email"]:focus,
form input[type="password"]:focus {
    border-color: #007bff;
    outline: none;
}

form button[type="submit"] {
    width: 100%;
    background: #007bff;
    color: #fff;
    border: none;
    padding: 12px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.3s ease;
}

form button[type="submit"]:hover {
    background: #0056b3;
}

button[onclick="volver()"] {
    margin-top: 20px;
    width: 100%;
    background: #6c757d;
    color: #fff;
    border: none;
    padding: 12px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.3s ease;
}

button[onclick="volver()"]:hover {
    background: #5a6268;
}
.btn-volver {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    background-color: #000;
    color: #fff;
    padding: 8px 14px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
  }
  .btn-volver:hover {
    background-color: #fff;
    color: #000;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.3);
  }