body {
  padding: 0;
  margin: 0;

  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  header {
    position: absolute;

    width: 100%;
    height: 150px;

    padding: 25px;
    box-sizing: border-box;

    background-color: #ff00ff;
    color: #006505;

    font-weight: 700;

    transition: all 1s ease-in-out;

    &.fixed {
      position: fixed;
      top: 0;

      width: 50%;
      margin: 0 25%;
    }

    ul {
      list-style: none;

      li {
        display: inline-block;
        padding-left: 25px;
      }
    }
  }

  section {

    width: 100%;
    padding: 200px 25%;
    box-sizing: border-box;

    color: #bfffc0;
    background-color: #00a0d2;
  }

  footer {
    position: fixed;
    bottom: 0;

    width: 50%;
    height: 100px;

    margin: 0 25%;

    background-color: white;

    transition: all 1s ease-in-out;

    &.relative {
      position: relative;
      height: 700px;
      width: 100%;
      margin:0;
    }

    ul {
      list-style: none;

      li {
        display: inline-block;
        padding-left: 25px;
      }
    }
  }
}