* {
  margin: 0;
  padding: 0;
}

body {
  font-family: Lucida Grande;
  font-size: 12px;
}

#root-view {
  height: 100%;
  height: 100%;
  overflow-y: auto;
  position: relative;
  background-image: url(static/images/linen.png);
}

.column {
  position: absolute;
  width: 100%;
  height: 100%;
  overflow-y: hidden;
}

.row {
  position: absolute;
  width: 100%;
  height: 100%;
  overflow-x: hidden;
}

.column > *, .row > * {
  position: absolute;
  width: 100%;
  height: 100%;
}


* {
  margin: 0;
  padding: 0;
}

body {
  font-family: Lucida Grande;
  font-size: 12px;
}

#root-view {
  height: 100%;
  height: 100%;
  overflow-y: auto;
  position: relative;
  background-image: url(static/images/linen.png);
}

.column {
  position: absolute;
  width: 100%;
  height: 100%;
  overflow-y: hidden;
}

.row {
  position: absolute;
  width: 100%;
  height: 100%;
  overflow-x: hidden;
}

.column > *, .row > * {
  position: absolute;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  -webkit-box-shadow: inset 0px 0px 2px 2px rgba(0, 0, 0, .1);
}

.row > * + * {
  border-left: 5px solid #515151;
}

.column > * + * {
  border-top: 5px solid #515151;
}

Add a border and subtle inset shadow when panes are split.
Add a border and subtle inset shadow when panes are split.