<style>
  .container {
    margin-top: -1px;
    font-size: 10px;
    font-family: Ahem;
    color: green;
  }
</style>

<div style="width: 100px; background-color: green; padding-top: 50px;">
  <div style="float: left; width: 100px; height: 100px;"></div>
  <div class=container>should be right below the blue box</div>
</div>