body {
    font-family: 'Segoe UI', sans-serif;
    background: #f4f7fa;
    margin: 0;
    padding: 0;
}
header {
    background: #1a1f71;
    color: white;
    padding: 2em;
    text-align: center;
}
header h1 {
    margin: 0;
}
.banner {
    background: #0070ba;
    color: white;
    padding: 1em;
    text-align: center;
    font-size: 1.2em;
}
main {
    padding: 2em;
    max-width: 1000px;
    margin: auto;
}
section {
    margin-bottom: 2.5em;
}
ul {
    list-style: none;
    padding-left: 0;
}
li {
    margin-bottom: 1.2em;
}
.card {
    background: white;
    padding: 1em;
    border-radius: 10px;
    box-shadow: 0 0 8px rgba(0,0,0,0.1);
}
a {
    color: #0070ba;
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}
.paypal-button {
    display: inline-block;
    background: #0070ba;
    color: white;
    padding: 8px 15px;
    border-radius: 5px;
    margin-top: 10px;
    text-decoration: none;
}
footer {
    background: #1a1f71;
    color: white;
    text-align: center;
    padding: 1em;
    font-size: 0.9em;
}
.whatsapp {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: #25D366;
    color: white;
    padding: 10px 15px;
    border-radius: 50px;
    text-decoration: none;
    font-size: 18px;
}
.youtube-link {
    margin-top: 10px;
    display: inline-block;
    background: red;
    color: white;
    padding: 8px 14px;
    border-radius: 5px;
    text-decoration: none;
}

@media screen and (max-width: 768px) {
    header, footer {
        padding: 1.5em;
        font-size: 1em;
    }
    .banner {
        font-size: 1em;
        padding: 1em;
    }
    main {
        padding: 1.5em;
    }
    .card {
        font-size: 0.95em;
    }
    .paypal-button {
        padding: 10px;
        font-size: 15px;
    }
    .youtube-link {
        padding: 6px 12px;
        font-size: 14px;
    }
    .whatsapp {
        font-size: 16px;
        padding: 10px;
    }
}

.whatsapp {
    position: relative;
    display: inline-block;
    background: #25D366;
    color: white;
    padding: 10px 20px;
    border-radius: 30px;
    text-decoration: none;
    font-size: 18px;
    margin-top: 15px;
}
footer .whatsapp-container {
    margin-top: 10px;
}

footer .whatsapp-container {
    text-align: center;
}

footer .whatsapp {
    position: relative;
    background: #25D366;
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 18px;
    text-decoration: none;
    display: inline-block;
    margin-bottom: 10px;
}

@media screen and (max-width: 768px) {
    footer .whatsapp {
        font-size: 16px;
        padding: 10px 20px;
    }
}