Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class="ratio">
  <div class="fpp">
    <div class="fpp-inner">
        <div class="field--name-field-fpp-text-body"> More text perhaps, was on the dockett, we could never be sure. How many words will need to fit in the box?</div>
        <div class="field--name-field-fpp-text-url"> And what if there's more? What then?</div>
    </div> 
  </div>
</div>

SassMeister-input.scss

// ----
// Sass (v3.4.7)
// Compass (v1.0.1)
// ----

.ratio {
height: 0;
text-align: center;
background: #EEE;
margin: 20px;
padding-top: 25%; // Ratio of BG image
max-width: 40%; // just for demo purposes to keep it small
position: relative;
}

.fpp {
display: inline-block;
vertical-align: middle;
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
box-sizing: border-box;
}

.fpp:before {
content: '';
display: inline-block;
height: 100%;
vertical-align: middle;
}

.fpp-inner {
display: inline-block;
vertical-align: middle;
width: 98%;
background: #F5F5F5;
}

SassMeister-output.css

.ratio {
  height: 0;
  text-align: center;
  background: #EEE;
  margin: 20px;
  padding-top: 25%;
  max-width: 40%;
  position: relative;
}

.fpp {
  display: inline-block;
  vertical-align: middle;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
}

.fpp:before {
  content: '';
  display: inline-block;
  height: 100%;
  vertical-align: middle;
}

.fpp-inner {
  display: inline-block;
  vertical-align: middle;
  width: 98%;
  background: #F5F5F5;
}

SassMeister-rendered.html

<div class="ratio">
  <div class="fpp">
    <div class="fpp-inner">
        <div class="field--name-field-fpp-text-body"> More text perhaps, was on the dockett, we could never be sure. How many words will need to fit in the box?</div>
        <div class="field--name-field-fpp-text-url"> And what if there's more? What then?</div>
    </div> 
  </div>
</div>