Using splash-container in Pure CSS

Question

I'm using a splash-container this way:

<div class="splash-container">
  <div class="splash">
     <h1 class="splash-head">Ciencias de la Legislación</h1>
     <p class="splash-subhead">
       Listado de archivos disponibles.
     </p>
  </div>
</div>

With the following CSS:

.splash-container {
  background: #595959;
  z-index: 1;
  overflow: hidden;
  width: 100%;
  height: 40%;
  top: 0;
  left: 0;
  /*position: fixed !important;*/
}

But I have a small space between the navbar and the splash-containe, As you can see here:

Is there a way to fix it?