CodePen

HTML

            
              <footer>
  <div class="row">
    <div class="col"></div>
    <div class="col"></div>
    <div class="col"></div>
  </div>
  <div class="row">
    <div class="col"></div>
    <div class="col"></div>
    <div class="col"></div>
  </div>
</footer>
            
          
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CSS

            
              * {
  box-sizing:border-box;
}

footer {

  width:960px;
  margin:25px auto;
}

.row {
  padding:10px 0;
  background:#bada55;
  overflow:hidden;
}

.col {
  float:left;
  border:1px solid grey;
  width:29.333%;
  /*100 - 88 = 12 / 4 = 3
  */
  margin-left:3%;
  height:100px;
  background:NavajoWhite;
}
            
          
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JS

            
              
            
          
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