Centre div in remaining line space - html

Question

I'm trying to work out the best way using CSS to keep Block 2 centred in the remaining space that exists to the right of Block 1. This space could increase or decrease with the size of the browser window / orientation of device. Block1's position does not move.
I was hoping to be able to use a combination of float, margin-left:auto and margin-right:auto as way of keep Block2 centred, however, sadly my CSS is still in it's infancy.
Any guidance / help would be greatly appreciated.
#block1 {
position:relative;
top:10px;
left:0px;
width:50px;
height:100px;
background-color:#009;
}
#block2 {
position:relative;
width:100px;
height:100px;
top:10px;
float:right;
margin-left:auto;
margin-right:auto;
background-color:#999;
}
<div id="block1"></div>
<div id="block2"></div>
http://jsfiddle.net/d4agp0h6/
Thanks in advance

Answer 1

An easier way to do this would be to use nested divs rather than trying to position two within the same block element.
Here's the updated jsFiddle
So, you create a wrapper (#block1) which is the size of the entire page so you can move stuff around inside. Position each subsequent piece of content within this area so you can set margins, position, etc.
HTML
<div id="block1">
<div id="block2">
<div id="content">
<p>This is some text</p>
</div>
</div>
</div>
Then, with your CSS, set the positions relative to one another so you can use margins and percentage spacing to keep things fluid.
CSS
#block1 {
position:relative;
top:10px;
left:0px;
width:200px;
height:400px;
background:#555;
}
#block2 {
position:relative;
width:75%;
height:100%;
float:right;
margin:0 auto;
background-color:#999;
}
#content {
margin:0 auto;
border:1px solid black;
position:relative;
top:45%;
}
#content p {
text-align:center;
}

Answer 2

It appears you want a fixed side bar and a fluid content area.
DEMO: http://jsfiddle.net/fem4uf6c/1/
CSS:
body, html {padding:0;margin:0;}
#side {
width: 50px;
background-color: red;
box-sizing: border-box;
float: left;
height: 500px;
position: relative;
z-index: 1;
}
.content {
position: relative;
box-sizing: border-box;
width: 100%;
padding: 20px 20px 20px 70px;
text-align: center;
}
#box2 {
width: 50%;
height: 300px;
background: purple;
margin: 0 auto;
}
HTML:
<div id="side"></div>
<div class="content">
<p>This is the content box. Text inside here centers. Block items need margin: 0 auto; inline and inline-blocks will auto center.</p>
<div id="box2"></div>
</div>

Answer 3

Here is my take on a solution. I used Brian Bennett's fiddle as a base, since I agreed with how he laid out the markup and was going to do something similar myself.
Link to JSFiddle
Where I differed is to add a container section:
<section id='container'>
<div id="block1"></div>
<div id="block2">
<div id="content">
<p>This is some text</p>
</div>
</div>
</section>
I also used percentages to determine widths instead of px values - with the exception of #container. Changing the width of the container should demonstrate that the relevant content is always centered.

Answer 4

Option 1
Here is one of the correct way of putting Block side by side... where one Block is on the Top Left... and the other Block is Top Center
Working Demo 1 : http://jsfiddle.net/wjtnddy5/
HTML
<div id="mainBlock">
<div id="block1">
<div class="box"></div>
</div>
<div id="block2">
<div class="box"></div>
</div>
</div>
CSS:
html, body {
height:100%;
margin:0;
padding:0;
}
#mainBlock {
height:98%;
width:98.9%;
border:5px solid #000;
}
#block1 {
width:10%;
height:100px;
display:inline-block;
border:1px solid #ff0000;
overflow:hidden;
}
#block2 {
width:89.2%;
height:100px;
margin-left:auto;
margin-right:auto;
border:1px solid #ff0000;
display:inline-block;
}
.box {
margin:0 auto;
background-color:#009;
width:100px;
height:100px;
}
Its using the "display:inline-block;" to put Blocks side by side which is better than using Float technique... let me know incase you need only Float!
Option 2
Here is the Other technique using "float: left" incase you need this only...
For this I have just replaced "display:inline-block" with "float: left" for both Blocks.... rest is same..
Working Demo 2 : http://jsfiddle.net/h78poh52/
Hope this will help!!!