body {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', sans-serif;

    /* Imagen o fondo claro */
    background: 
        linear-gradient(rgba(0, 0, 0, 0.15), rgba(0, 0, 0, 0.15)), 
        url('imagenes/tu-imagen-de-fondo.jpg') no-repeat center center fixed;
    background-size: cover;
}

/* 🔷 Franja superior fija */
.franja-superior {
    background-color: #002147; /* Azul oscuro */
    height: 60px;
    width: 100%;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 999;
}

/* 🔶 Contenedor centrado */
.contenedor-login {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    box-sizing: border-box;
}

/* 🔷 Caja de login */
.login-box {
    background-color: rgba(255, 255, 255, 0.9);
    padding: 30px;
    border-radius: 10px;
    width: 100%;
    max-width: 400px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.15);
    position: relative;
    z-index: 10;
    margin-top: 80px; /* 🔹 separa un poco del borde superior */
}

/* Encabezado */
.login-header {
    text-align: center;
    margin-bottom: 20px;
}

.login-header h4 {
    margin: 10px 0 5px;
    color: #003366;
}

.login-header p {
    font-size: 14px;
    color: #666;
}

/* Inputs */
form label {
    display: block;
    margin: 10px 0 5px;
    font-weight: bold;
}

form input[type="text"],
form input[type="password"] {
    width: 100%;
    padding: 10px;
    margin-bottom: 12px;
    border: 1px solid #ccc;
    border-radius: 6px;
    box-sizing: border-box;
}

/* Grupo de contraseña */
.password-group {
    position: relative;
}

.password-group span {
    position: absolute;
    right: 10px;
    top: 9px;
    cursor: pointer;
    font-size: 18px;
}

/* Botón de login */
button {
    width: 100%;
    background-color: #003366;
    color: white;
    padding: 12px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    margin-top: 10px;
    font-weight: bold;
}

button:hover {
    background-color: #005099;
}

/* Botón secundario */
.btn-secundario {
    display: block;
    text-align: center;
    margin-top: 10px;
    color: #003366;
    text-decoration: none;
    border: 1px solid #003366;
    padding: 10px;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.btn-secundario:hover {
    background-color: #003366;
    color: white;
}

/* Mensajes */
.alert {
    padding: 10px;
    margin-bottom: 15px;
    border-radius: 6px;
    text-align: center;
}

.alert.exito {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}