how to keep floated item centered within container - html

Question

OK, I've gotten the prelim version of my page started, but I'm having a problem with two floated div's that are wrap in header tag. Basically, I want the two rectangles to center within the containing div tag. One of the rectangles overlaps the other. I had to us positioning to be able to expand them within the container other-wise the second would jump below the first.
Here's what I've have so far.
<div id="div1" class="fluid">
<header id="headGraphics">
<div id="headRectangle1">This will be an image.</div>
<div id="headRectangle2">"This will be text adjusted using opacity."
</div>
Here is the css for the page - I have a follow-up question after we get this solved.
.gridContainer.clearfix #headGraphics {
margin-top: 0px;
margin-right: auto;
margin-left: auto;
margin-bottom: 0px;
font-family: "monotype corsiva";
font-size: 20px;
font-weight: 800;
width: 950px;
text-align: center;
}
.gridContainer.clearfix #headGraphics #headRectangle1 {
float: left;
width: 350px;
height: 75px;
position: relative;
border: medium solid #000000;
-webkit-box-shadow: 3px 3px 3px 1px #FF7878;
box-shadow: 3px 3px 3px 1px #FF7878;
margin-left: auto;
margin-right: auto;
display: inline-block;
}
.gridContainer.clearfix #headGraphics #headRectangle2 {
background-color: #FFAAAA;
float: left;
/*margin-right: 50px;*/
width: 350px;
height: 75px;
position: relative;
top: -50px;
right: 0px;
text-align: center;
clear: both;
left: 100px;
margin-left: auto;
margin-right: auto;
display: block;
}
.gridContainer.clearfix #headGraphics:after {
content: " ";
display: table;
clear: both;
}
I can't remove the position tags because they give me the layout that I'm am trying to accomplish.
Let ma know if you need more info. Thank you in advance. And yes, I have searched this page and others to find a solution, but none seem to apply to my particular situation.
let me clear a few things up... and before I go any further, most of my (98%) selectors are in the boiler plate template. That being said, here the computed effects per selector:
.gridContainer.clearfix #headGraphics;
width 950px, margin 0 auto, font-family monotype weight 800px size 20px, text-align center.
.gridContainer.clearfix #headGraphics #headRectangle1;
width 350px, height 75px, display inline-block, margin rt & lft auto, position relative, box-shadow (which isn't working properly)
.gridContainer.clearfix #headGraphics #headRectangle2
width 350px, height 75px, display inline-block, position relative, top -50px, rt 0px, bot 0px, left 100px (this is to bring object up and offset from rectangle), float left, clear both, text-aligh center.

Answer 1

I would suggest removing the float attributes from both, then just setting both items display as inline-block, you will need to specify width and height on both cases, then apply text-align center to the parent, that will allow the child to be centered to the parents available area.
The Display: inline-block will give the two elements the possibility to behave not just like a block element, it will be both, block and inline, so you will be able to use attributes for both at the same time.
If you need an example, I can provide you with one, Just let me know!
EDIT...
Here is a working example
My JSFiddle
http://jsfiddle.net/dq185dw9/
My CSS
#headGraphics {
margin-top: 0px;
margin-right: auto;
margin-left: auto;
margin-bottom: 0px;
font-family: "monotype corsiva";
font-size: 20px;
font-weight: 800;
width: 950px;
text-align: center;
outline: red dashed 1px;
padding: 35px; /* remove or change if needed */
}
#headGraphics [id*="headRectangle"] {
width: 350px;
height: 75px;
position: relative;
border: medium solid #000000;
-webkit-box-shadow: 3px 3px 3px 1px #FF7878;
box-shadow: 3px 3px 3px 1px #FF7878;
display: inline-block;
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
-ms-box-sizing: border-box;
-o-box-sizing: border-box;
-khtml-box-sizing: border-box;
box-sizing: border-box;
margin: 0px 25px;
line-height: 75px; /* remove or change if you want to have more than one line of text */
}
My HTML
<header id="headGraphics">
<div id="headRectangle1">This will be an image.</div>
<div id="headRectangle2">"This will be text adjusted using opacity.</div>
</header>