/* 
background
foreground
header
site-title
page-content
footer
*/ 

html, body {
  margin: 0;
  height: 100%;  
  width: 100%;

  overflow: hidden;    
  display: flex;
  justify-content: center;
  align-items: center;  
}

.background {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-size: cover;
  background-position: center;
  z-index: 0;
  background-color: red;
}

.foreground {
  position: relative;
  z-index: 1;
  height: 100%;      
  overflow-y: auto;          
  -webkit-overflow-scrolling: touch;
  box-sizing: border-box;
  padding: 2rem;
  background-color: rgb(255, 255, 255);
  width: 50%;
}