[html] How to position text over an image in css

For a responsive design it is good to use a container having a relative layout and content (placed in container) having fixed layout as.

CSS Styles:

/*Centering element in a base container*/

.contianer-relative{ 
  position: relative;
 }

.content-center-text-absolute{ 
  position: absolute; 
  text-align: center;
  width: 100%;
  height: 0%;
  margin: auto;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  z-index: 51;
}

HTML code:

<!-- Have used ionic classes -->
<div class="row">
    <div class="col remove-padding contianer-relative"><!-- container with position relative -->
        <div class="item item-image clear-border" ><a href="#"><img ng-src="img/engg-manl.png" alt="ENGINEERING MANUAL" title="ENGINEERING MANUAL" ></a></div> <!-- Image intended to work as a background -->
        <h4 class="content-center-text-absolute white-text"><strong>ENGINEERING <br> MANUALS</strong></h4><!-- content div with position fixed -->
    </div>
    <div class="col remove-padding contianer-relative"><!-- container with position relative -->
        <div class="item item-image clear-border"><a href="#"><img ng-src="img/contract-directory.png" alt="CONTRACTOR DIRECTORY" title="CONTRACTOR DIRECTORY"></a></div><!-- Image intended to work as a background -->
        <h4 class="content-center-text-absolute white-text"><strong>CONTRACTOR <br> DIRECTORY</strong></h4><!-- content div with position fixed -->
    </div>       
</div>

For IONIC Grid layout, evenly spaced grid elements and the classes used in above HTML, please refer - Grid: Evenly Spaced Columns. Hope it helps you out... :)