Canvas Pattern in CSS

Reading Jenifer Tidwell's Designing Interfaces, which is a book on design patterns for UI design, I learned a name for interfaces like MS Paint, and similar: The Canvas Pattern.

What I wanted to do is create a full screen canvas, with "toolbars" docked left and right.

HTML:

<div class="canvas-pattern">
    <div class="canvas-pattern-left"></div>
    <div class="canvas-pattern-canvas"></div>
    <div class="canvas-pattern-right"></div>
</div>

CSS:

/* canvas-pattern */
/** full screen */
.canvas-pattern-canvas{
    position: fixed;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    z-index: -10;
    background-color: lightblue;
}

/*** centered within fullscreen */
.canvas-pattern-canvas > div {
    width: 300px;
    position: fixed;
    top: 50%;
    left: 50%;
}

/** docking ... */
.canvas-pattern{
    position: relative;
}

/*** ... right */
.canvas-pattern-right{
    position: absolute;
    top: 0;
    right: 0;
}

/*** ... left */
.canvas-pattern-left{
    position: absolute;
    top: 0;
    left: 0;
}

Enjoy!