nav {
  display: flex;
  justify-content: space-between;
  max-width: 900px;
}

header{
  background-image: url(http://placehold.it/900x300);
  height: 300px;
  max-width: 900px;
  display: flex;
  justify-content: center;
}

header div {
  text-align: center;
  height: inherit;
  /*padding-top: 75px;*/
}
#button {
  border: 1px solid black;
  width: 50px;
  height: 20px;
  color: black;
  margin: auto;
}
main {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  /*max-width: 900px;*/
}
.four {
  display: flex;
  /*flex-wrap: wrap;*/

  justify-content: space-between;
  ;
}
section img {
  display: flex;
  /*padding-right: 50px;
  padding-left: 50px;*/

  margin: inherit;
}
article {
  justify-content: space-around;
  flex-wrap: wrap;
}
section p {
  /*justify-content: space-around;*/
  /*padding: 50px;*/
  /*margin: inherit;*/
}

/*
main section{
  float:left;
  text-align: center;
  padding: 50px;
}*/
section {
  display: flex;
  margin: 50px;
  justify-content: space-around;
  max-width: 900px;
}
main h2 {
  width: 600px;
}