.sidebar-ad {
    position: fixed;
    top: 150px;
    left: 20px;
    z-index: 100;
}

.banner-ad {
    display: flex;
    justify-content: center;
    margin: 40px 0;
}

/* Hide sidebar on mobile */
@media (max-width: 768px) {
    .sidebar-ad {
        display: none;
    }
}