How to make a div cover the whole screen
<p>I have a question. </p>

<p>I got this so far: 
<a href="https://i.stack.imgur.com/llcqJ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/llcqJ.png" alt="enter image description here"></a></p>

<p>I basically want the highlighted div to cover your device screen no matter how big the device screen is. now i see 2 different divs when i open this on my phone. i only want to see the one that is highlighted. How do I achieve this? </p>

<p>Thanks in advance, 
kevin</p>