body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #1c1c3c, #2a2a72);
    color: white;
    margin: 0;
    padding: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 40px;
    width: 350px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(10px);
    transition: transform 0.3s ease-in-out;
}

.container:hover {
    transform: scale(1.05);
}

h1 {
    font-size: 24px;
    color: #f1f1f1;
    text-align: center;
    margin-bottom: 20px;
    letter-spacing: 1px;
}

.factura-details {
    background-color: rgba(255, 255, 255, 0.2);
    padding: 20px;
    border-radius: 10px;
    text-align: left;
    margin-bottom: 20px;
}

.factura-details p {
    margin: 5px 0;
    font-size: 14px;
}

.factura-details p span {
    color: #ffdf00;
}

.file-links {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.file-links a {
    background-color: #007bff;
    color: white;
    text-decoration: none;
    padding: 15px;
    border-radius: 10px;
    text-align: center;
    transition: background-color 0.3s ease;
    font-size: 14px;
}

.file-links a:hover {
    background-color: #0056b3;
}

.file-links a:first-child {
    background-color: #f5b623;
    color: white;
}

.file-links a:first-child:hover {
    background-color: #d4930e;
}

footer {
    margin-top: 20px;
    text-align: center;
    font-size: 12px;
    color: #ccc;
}

/* Responsive Web Design */
@media (max-width: 768px) {
    body {
        padding: 20px;
        height: auto;
    }

    .container {
        width: 100%;
        padding: 20px;
        box-shadow: none;
        border-radius: 10px;
    }

    h1 {
        font-size: 20px;
    }

    .factura-details {
        padding: 15px;
    }

    .factura-details p {
        font-size: 13px;
    }

    .file-links a {
        padding: 10px;
        font-size: 13px;
    }
}

@media (max-width: 576px) {
    h1 {
        font-size: 18px;
    }

    .factura-details p {
        font-size: 12px;
    }

    .file-links a {
        padding: 8px;
        font-size: 12px;
    }
}