UI / CSS: DNA bars not properly formatted

[diva-exchange]

See Block 19:

[diva-exchange]

HTML / CSS:

<div class="column block-dna is-4">
  <div class="dna dna-data" style="width: 56.3%"></div>
  <div class="dna dna-decision" style="width: 43.8%"></div>
</div>

Problem: rounding error, width calculation