.dialog-background {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background-color: rgba(0,0,0,0.5);
  padding: 0.5em;
  text-align: center;
  -moz-box-sizing: border-box; box-sizing: border-box;
  z-index: 1001;
}

.dialog-outer {
  position: relative;
  width: 100%;
  height: 100%;
}

.dialog {
  position: relative;
  background-color: white;
  padding: 2em;
  box-shadow: 1px 1px 3px rgba(0,0,0,0.1);
  margin: 0 auto;
  display: inline-block;
  max-width: 100%;
  max-height: 100%;
  overflow-y: auto;
  -moz-box-sizing: border-box; box-sizing: border-box;
}