程式設計@筆記

<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
@media screen and (min-width: 721px) {

.content .x700{display:block !important;}
.content .x490{display:none !important;}
.content .x290{display:none !important;}

}

@media screen and (max-width: 720px) {

.content .x700{display:none !important;}
.content .x490{display:block !important;}
.content .x290{display:none !important;}

}

@media screen and (max-width: 479px) {

.content .x700{display:none !important;}
.content .x490{display:none !important;}
.content .x290{display:block !important;}

}
</style>

<div class="content">
<div class="x700">this is the content for desktop</div>
<div class="x490">this is the content for tablet</div>
<div class="x290">this is the content for mobile</div>
</div>