<style>
.container {
	padding: 10px;
    height: 100px;
    width: 100px;
    position: relative;
    background-color: green;
}

div div {
	background: blue;
    position: absolute;
    top: 0px;
    left: 0px;
    height: 10px;
}
</style>
<div class=container>
    <div style="max-width: 10%; width: 100%;"></div>
    <div style="top: 10px; min-width: 100%; width: 10%;"></div>
</div>