demo.css

@import url("https://fonts.googleapis.com/css?family=Fascinate");

* {
  margin: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

html, body {
  padding: 0;
  margin: 0;
  height: 100%;
  width: 100%;
  background-color: floralwhite;
}

.esri-component.esri-attribution.esri-widget {
  opacity: 0.6;
  background-color: transparent;
}

img {
  border: 1px solid black;
}

header {
  position: absolute;
  left: 0;
  top: 0;
  padding: 20px;
  font-family: "Avenir Next W01", "Avenir Next W00", "Avenir Next", "Avenir", "Helvetica Neue", Helvetica, Arial,
    sans-serif;
  font-size: 1.7em;
  font-weight: bold;
  z-index: 2;
  text-shadow: -1px 0 white, 0 1px white, 1px 0 white, 0 -1px white;
}

div.top {
  width: 50%;
  height: 50%;
  float: left;
}

div.top:nth-of-type(1) {
  background: #ccc;
}

div.top:nth-of-type(2) {
  background: #bbb;
  border-left: 1px solid #f00;
}

div.top:nth-of-type(3) {
  background: #aaa;
  border-top: 1px solid #f00;
}

div.top:nth-of-type(4) {
  background: #ddd;
  border-top: 1px solid #f00;
  border-left: 1px solid #f00;
}