How to make container 100% of parent if it have ul inside

Question

I have markup:

http://jsfiddle.net/ZVXFD/85/

i need to make .step of 100% of parent container, how to accomplish that. html:

 <div class="steps-container">
        <div class="group">
            <div class="step">
                <ul class="sortable">
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                </ul>
            </div>
            <div class="step">
                <ul class="sortable">
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                    <li class="item">Item</li>

                </ul>
            </div>
            <div class="step">
                <ul class="sortable">
                    <li class="item">Item</li>
                    <li class="item">Item</li>
                </ul>
            </div>
        </div>

    </div>

css:

* {
    margin: 0px;
    padding: 0px;
}

ul {
    list-style-type: none;
    margin: 0px;
    padding: 0px;
    display: inline-block;
}

.sortable li {
    margin: 0px;
    padding: 0px;
    width: 100px;
    height: 100px;
    border: 1px solid black;
    background-color: lightgrey;
}


.group {
    display:inline-block;
    border: 1px solid red;
}

.step {
    border: 1px solid green;
    display:inline-block;
    background-color: yellow;
}

.item {
    background-color: lightgray;
}

Answer 1

You could set position: relative; to .group

and

position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;

to .step

I'm assuming you are showing only one .step element at the time, am I wrong?

Answer 2

http://jsfiddle.net/ZVXFD/94/

If you want .group to be 100% wide, you'll need these styles:

.group {
    border: 1px solid red;
    display:table; /* make the element 100% fill the entire available width */
    width: 100%;
}

If you want .step to be equal height, you'll need these styles:

.step {
    border: 1px solid green;
    display:table-cell; /* make the element 100% of its parent's height/equal height columns */
    background-color: yellow;
}