@import url(http://fonts.lug.ustc.edu.cn/css?family=Roboto+Slab:400,700);

.section{
  font-family: 'Roboto Slab', serif;
  font-weight: 500;
  font-size: 2em;
  color: #fff;
  box-sizing: border-box;
  width: 100%;
  position: relative;
  float: left;
  text-align: center;
  
  &:nth-child(1){
    height: 100vh;
    line-height: 100vh;
    background: #3498db;
  }
  &:nth-child(2){
    height: 90vh;
    line-height: 90vh;
    background: #e74c3c;
  }
  &:nth-child(3){
    height: 70vh;
    line-height: 70vh;
    background: #1abc9c;
  }
  &:nth-child(4){
    height: 100vh;
    line-height: 100vh;
    background: blue;
    background-size: cover;
  }
}