media query for width and height code example
Example 1: min and max width media query
@media (max-width: 989px) and (min-width: 768px) {}
Example 2: media query in html style
span { background-image: url(particular_ad.png); }
@media (max-width: 300px) {
span { background-image: url(particular_ad_small.png); }
}