Keep Text Centered when resizing

So I have looked at other questions like this, yet none have solved my problem. What I want to be able to do is resize the window of the browser, yet keep the text in the centre of the window.

HTML:

<div id=inside>
Navjeeven Mann
</div>

CSS:

#inside {
  position:relative;
  width: 100%;
  height: 100%;
  font-size: 60px;
  text-align: center;
  color: black;
  top:50%;
  left:50%;
}

What it looks like now



To keep it centred horizontally, remove the top:50%;left:50%;

#inside {
  position:relative;
  width: 100%;
  height: 100%;
  font-size: 60px;
  text-align: center;
  color: black;
}
<div id="inside">
  Navjeeven Mann
</div>

To center it horizontally and vertically, flex really does the job well, unless you have to support older browsers.

html, body {
  margin: 0;
}

#inside {
  display: flex;
  width: 100vw;
  height: 100vh;
  align-items: center;
  justify-content: center;
  font-size: 60px;
}
<div id="inside">
  Navjeeven Mann
</div>

Looks like you want the text vertically and horizontally centered inside a div. I would first wrap your text inside a p tag. Then changeup the css a bit so your code will look like this:

This should work across all devices