Page 104 - CSS

margin-top: -100px; /* width * -0.5 */
}

Using margin: 0 auto;

Objects can be centered by using margin: 0 auto; if they are block elements and have a defined
width.

HTML

<div class="containerDiv">
<div id="centeredDiv"></div>
</div>

<div class="containerDiv">
<p id="centeredParagraph">This is a centered paragraph.</p>
</div>

<div class="containerDiv">
<img id="centeredImage" src="https://i.kinja-img.com/gawker-media/image/upload/s--
c7Q9b4Eh--/c_scale,fl_progressive,q_80,w_800/qqyvc3bkpyl3mfhr8all.jpg" />
</div>

CSS

.containerDiv {
width: 100%;
height: 100px;
padding-bottom: 40px;
}

#centeredDiv {
margin: 0 auto;
width: 200px;
height: 100px;
border: 1px solid #000;
}

#centeredParagraph {
width: 200px;
margin: 0 auto;
}

#centeredImage {
display: block;
width: 200px;
margin: 0 auto;
}

Result:

https://riptutorial.com/ 82