presentation.css

img, a {border:none, outline: none;}

.reveal table th, .reveal table td {
    text-align: center;
    border: 1px solid white;
}

.reveal pre {
    width: 100%;
    border: none;
    box-shadow: none;
}

.main .row img {
    display: inline-block;
    border: 0px;
    background-color: transparent;
}

.noborder .reveal section img {
  background:none; 
  border:none; 
  box-shadow:none;
  }