.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4,
.reveal h5,
.reveal h6 {
  text-transform: none;
  /* margin-top: 100px; */
}

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


/* ref: https://stackoverflow.com/questions/30861845/how-to-use-two-column-layout-with-reveal-js#answer-44392145 */
.columns {
    display: flex;
}
.col {
    flex: 1;
}


/* fix position for better interaction on mobile devices */
/* html { */
/*     position: fixed; */
/* } */