body {
    margin: 0;
    padding: 0;
    font-family: "Segoe UI", Arial, sans-serif;
    text-align: center;
    color: #ffffff;

    background: linear-gradient(to bottom, #3a6ea5, #1b3f73);
    background-attachment: fixed;

    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Título estilo Aero */
h2 {
    margin-top: 60px;
    font-size: 44px;
    font-weight: 300;
    text-shadow: 0 2px 6px rgba(0, 0, 0, 0.6);
}

/* Caja efecto vidrio */
.container {
    margin-top: 60px;
    padding: 40px 60px;

    background: rgba(255, 255, 255, 0.15);
    border-radius: 18px;

    border: 1px solid rgba(255, 255, 255, 0.3);

    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    box-shadow:
        0 0 25px rgba(255, 255, 255, 0.2),
        0 15px 30px rgba(0, 0, 0, 0.5);
}

/* Botón estilo Windows 7 */
button {
    margin-top: 25px;
    padding: 12px 30px;
    font-size: 16px;
    font-family: inherit;
    color: #ffffff;

    background: linear-gradient(to bottom, #6db3f2, #1e69de);
    border: 1px solid #1b5fc4;
    border-radius: 6px;

    cursor: pointer;
    font-weight: 600;

    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.6),
        0 3px 8px rgba(0, 0, 0, 0.5);

    transition: 0.2s ease;
}

button:hover {
    background: linear-gradient(to bottom, #7fc7ff, #2a7bff);
}

button:active {
    transform: translateY(2px);
    box-shadow:
        inset 0 2px 6px rgba(0, 0, 0, 0.4);
}

/* Botón de regreso */
.back-btn {
    margin: 40px 0 60px 0;
    padding: 12px 30px;
    font-size: 16px;
    font-family: inherit;
    color: #ffffff;

    background: linear-gradient(to bottom, #a3c1ff, #4f86ff);
    border: 1px solid #3a6ee8;
    border-radius: 6px;

    cursor: pointer;
    font-weight: 600;

    box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.6),
        0 3px 8px rgba(0, 0, 0, 0.5);

    transition: 0.2s ease;
}

.back-btn:hover {
    background: linear-gradient(to bottom, #b9d2ff, #5d95ff);
}