style.css

html, body {
  padding: 0px;
  margin: 0px;
  height: 100%;
  width: 100%;
  background: transparent;
}

.tabbar {
  box-sizing: border-box;
  z-index: 1;
  position: relative;
  height: 43px;
  background: #222222;
  box-shadow: inset 0 -8px 8px -4px rgba(0, 0, 0, 0.15);
  padding: 0 0 0 10px;
  margin: 0;
  -webkit-app-region: drag;
}

.tabbar:window-inactive {
  background-color: red;
}

.tabbar:after {
  content: "";
  position: absolute;
  bottom: 0;
  height: 8px;
  left: 0px;
  width: 100%;
  background-color: #222222;
  border-top: 1px solid #484848;
  border-bottom: 1px solid #111111;
}

.tab.drag {
  background: red;
  -webkit-app-region: drag !important;
}

.draggable {
  height: 100px;
  width: 100px;
  background-color: red;
}

.tab.selected {
  z-index: 3;
}

.tab.selected:before {
  background-color: #FFF;
  background-image: -webkit-linear-gradient(top, #343434, #222222);
}

.tab:before {
  border-radius: 5px 5px 0 0;
  background: #EFEFEF;
  background-image: -webkit-linear-gradient(top, #454545, #333333);
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: -1;
  border-left: 1px solid #AAA;
  border-right: 1px solid #AAA;
  border-top: 1px solid #AAA;
  border-bottom: none;
  border: none;
  box-shadow: inset 1px 1px 0 #484848, -4px 0px 4px rgba(0, 0, 0, 0.1);
  -webkit-transform: perspective(5px) rotateX(1deg);
  -webkit-transform-origin: bottom;
  -webkit-app-region: no-drag;
}

.tab {
  padding-top: 8px;
  padding-left: 25px;
  box-sizing: border-box;
  height: 36px;
  width: 180px;
  font-size: 0.8em;

  position: absolute;
  display: inline-block;
  text-align: left;
  font-family: sans-serif;
  color: #585858;
  z-index: 2;

  top: 5px;
  height: 30px;
  line-height: 17px;
  color: #aaaaaa;

  transition: color 0.1s ease-in;
}