.lesrooster {
  border-collapse: collapse;
  width: 100%;
}
.lesrooster td, .lesrooster th {
  border: 1px solid #aaa;
  padding: 0;
  text-align: center;
  vertical-align: top;
  width: 14.28%;
  position: relative;
}
.lesrooster .tijd {
  width: 60px;
  background: #f0f0f0;
  font-weight: bold;
}
.lesblok {
  background: #cde;
  margin: 0;
  padding: 2px;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  border-radius: 4px;
  cursor: move;
}
.lesblok.dragging {
  opacity: 0.5;
}
.ruilknop {
  display: inline-block;
  font-size: 0.8em;
  background: #eef;
  padding: 2px 4px;
  margin-top: 4px;
  border: 1px solid #88a;
  border-radius: 3px;
  text-decoration: none;
  color: #224;
}