body {
    font-family: Arial, sans-serif;
    background: #f5f5f5;
    margin: 0;
    padding: 20px;
}
h1 {
    color: #333;
}
#bannersList {
    margin-top: 20px;
}
.banner-item {
    background: #fff;
    border: 1px solid #ddd;
    padding: 15px;
    margin-bottom: 10px;
    border-radius: 8px;
}
#bannerPreview {
    margin-top: 20px;
}
pre {
    background: #eee;
    padding: 10px;
    border-radius: 6px;
    overflow-x: auto;
}

.ad-img-wrapper {
    width: 100%;
    height: auto;
    overflow: hidden;
    border-radius: 8px;
    background: #f8f8f8;
}
.ad-img-wrapper img {
    width: 100%;
    max-width: 100%;
    height: auto;
    max-height: 250px;
    object-fit: cover;
    display: block;
    margin: 0 auto;
}
@media (max-width: 600px) {
    .ad-img-wrapper img {
        max-height: 160px;
    }
}