Html <div class="row"> not centering - html

Question

First I'd like to say that I know very little about coding.
In this website I made http://academiadae.com, I added two small divs at each side, so I could get a div class="6u" centered.
<div class="row">
<div class="3u"></div>
<div class="6u"><img src="images/logo.png" /></div>
<div class="3u"></div>
</div>
Can you help me to get it centered without the need for the other divs?
I tried making different elements =center in the CSS, but it didn't work.
Thanks.

Answer 1

First of all, your are using as class 6u which will not be selected. A CSS name must begin with an underscore (_), a hyphen (-), or a letter(a–z) to use it as an CSS selector. You can check this page for any reference.
Second if you want to have the a single div centered you could apply this:
<div class="row">
<div class="item6u">
test
</div>
</div>
Where there is only one div with a class name that starts with a letter.
For you CSS you need to set the width of the div and like #Sprazer told you need to set the margin:
.row{
background-color:yellow;
}
.item6u{
background-color:red;
width:50%; //changed to 50% percentage as wawa suggested
margin:0 auto;
text-align:center;
}
See code here: JSFIDDLE.

Answer 2

So, you currently have something like: HTML
<div class="row">
<div class="3u">
</div>
<div class="6u">
<img src="images/logo.png">
</div>
<div class="3u">
</div>
</div>
and CSS:
div.6u{
width: 50%;
clear: none;
float:left;
margin-left: 0;
}
You need to change this to HTML:
<div class="row>
<div class="6u">
...contents of the div here...
</div>
</div>
and CSS (note: do remove float:left, otherwise it will not work):
div.6u{
width:50%;
clear:none;
margin-left:auto;
margin-right:auto;
}