html {
  box-sizing: border-box;
}

*, *:before, *:after {
  box-sizing: inherit;
}

body {
  display: block;
  margin: auto;
  font-family: "neuzeit-grotesk", Helvetica, sans-serif;
  background-color: beige;
}

/* header element */
header {
  width: 100%;
  height: 40px;
  padding-left: 20px;
  padding-right: 20px;
  top: 0;
  display: flex;
  flex-wrap: wrap;
  margin-left: auto;
  margin-right: auto;
  align-items: center;
  position: fixed;
  justify-content: space-between;
  z-index: 10;
  border-bottom: solid 1px;
  background-color: beige;
}

header h1 {
  font-size: 16px;
  font-weight: 700;
  padding-right: 50px;
  letter-spacing: 0.5px
}

header h1 a {
  text-decoration: none;
  color: black;
  cursor: crosshair;
}

nav a {
  font-size: 16px;
  font-weight: 300;
  text-decoration: none;
  padding-left: 10px;
  padding-right: 10px;
  color: black;
  cursor: crosshair;
}

nav a:hover {
  background-color: white;
  transition: .4s;
}

/* main element */
div.about {
  position: relative;
  width: 100%;
  margin-top: 40px;
  padding-left: 20px;
  padding-right: 20px;
}

div.introduction {
  float: left;
  width: 80%;
  padding-right: 50px;
}

.introduction p {
  font-family: "linotype-sabon", serif;
  font-size: 20px;
  font-weight: 400;
  line-height: 1.6;
}

p.introduction-add {
    font-size: 15px;
    line-height:1.6;
}

div.contact {
  margin-top: 25px;
  float: right;
  width: 20%;
  padding-left: 50px;
  margin-bottom: 100px;
}

.contact a {
  font-size: 14px;
  font-weight: 400;
  line-height: 2;
  text-decoration: none;
  color: black;
  cursor: crosshair;
}

.contact a:hover {
  text-decoration: underline;
}

/* footer element */
footer {
  margin-top: 100px;
  bottom: 0px;
  position: fixed;
  width: 100%;
  padding-left: 20px;
  padding-right: 20px;
  display: flex;
  flex-direction: row;
  border-top: solid 1px;
  background-color: beige;
}

footer p {
  font-size: 12px;
  font-weight: 300;
  color: grey;
}

/* media query */
@media only screen and (max-width:800px) {
  div.about {
    overflow: hidden;
  }

  div.introduction {
    display: block;
    width: 100%;
    padding-right: 0px;
  }

  .introduction p {
    font-size: 16px;
  }

  div.contact {
    display: block;
    width: 100%;
    padding-left: 0px;
  }