(CSS) How position text (with background color) over

Answer 1

position:relative solves your problem

Answer 2

I see no reason not to use position: absolute.

See: http://jsfiddle.net/NeaR4/

CSS:

.container {
    border: 2px dashed #444;
    float: left;
    position: relative
}
.container img {
    display: block
}
.container > div {
    position: absolute;
    left: 0;
    bottom: 0;
    right: 0;
    height: 14px;
    background: #000;
    background: rgba(0,0,0,0.7);
    color: #fff;
    overflow: hidden;
    font: bold 14px Arial, sans-serif;
    padding: 5px;
}
.container:hover > div {
    height: auto
}

HTML:

<div class="container">
    <img src="http://dummyimage.com/230x180/f0f/fff" />
    <div>some text with line oneeee, line twoooooooo ooooooo , line three</div>
</div>