Question: Is it possible to create an operating system that loads a web browser without menu bars, tabs etc. and that is all it loads.

I do not mean like Chrome OS but I mean all it loads is a html page which can be interacted with like an ordinary web page e.g. google.com, youtube.com.

Also, if this is possible, I would prefer it to be a Linux based OS and Webkit based browser.

Answer: 
What you want to do is make some CSS apply to two different types of elements, but allow them to have some differences as well. You can do this using some simple HTML:

```
<div class="base">
    <div class"inherited">
    </div>
</div>

```

And CSS:

```
.base, .inherited{
    margin-top:3px;
    margin-left:auto;
    margin-right:auto;
    margin-bottom:0px;
}

.inherited{
    background-image:url("images/worldsource/customBackground.gif");
    background-repeat:no-repeat;
    width:950px;
    height:572px;
}

```

This will add the shared properties to both types of `div`, but specific ones only to derived `div`s
If you want all the inner DIVs with a specific class to inherit from the base class build the HTML markup like this:

```
<div class="parent">
    <div class="child">X</div>
</div>

```

And the CSS

```
.parent { border: 2px solid red; color: white }
.parent .child { background: black }

```

If all DIVs must inherit change `.child` to `div`.

[**See this example on jsFiddle**](http://jsfiddle.net/Yeraq/)

The following code

```
// parent     // all DIVs inside the parent
.someClass    div { }

```

Means: A top element (any) with the class `someClass` will add the styles to all its children DIVs (recursively).