css media queriess code example

Example 1: minimum width of different devices in html

<meta name="viewport" content="width=device-width,initial-scale=1">

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); }
}