*, ::before, ::after {
    box-sizing: border-box;
}

body {
    padding: 0;
    margin: 0;
}
#baan {
    padding: 10px;
}
.naam {
    font-size: 1.2em;
}
.slider {
    width: 100%;
    padding-left: 25px;
    padding-right: 25px;
}
.slide {
    background-color: #9cf;
    width: 50px;
    height: 50px;
    position: relative;
    margin-left: -25px;
}

.slide.img {
    background-color: transparent;
    background-size: contain;
    background-position: center center;
    background-repeat: no-repeat;
}

#overlay {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  text-align: center;
  font-size: 4em;
  font-weight: bold;
}
#overlay::before {
  content: '';
  height: 100%;
  vertical-align: middle;
  display: inline-block;
}
#overlay:empty {
  display: none;
}