html, body {
  height: 100%;
  line-height: 1.4;
  /*font-family: 'Open sans', sans-serif*/
  font-family: 'Roboto', sans-serif;
  font-size: 16px;
  box-sizing: border-box; 
}

header {
  height: 100%;
  width: 100%;
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center;
  background-image: url("sleep.jpg"); 
}

header p {
  font-size: 2em;
  color: hsla(360, 50%, 50%, 1);
  text-align: center;
  position: relative;
  top: 2em;
  margin: auto;
}