* {
  margin: 0;
  padding: 0;
}


body {
  background-color: whitesmoke;
}

nav {
  background-color: white;
  font-size: larger;
  position: sticky;
  top: 0;
}

li {
  display: inline-block;
  margin: 20px 40px;
}

li a {
  text-decoration: none;
  color: black;
}

.article-section {
  display: flex;
  background-color: #ffb785;
}



.article-section article {
  max-width: 400px;
  margin: 40px auto;
  padding: 40px;
  line-height: 1.5;
  border-radius: 10px;
  font-size: 18px;
}

.article-section article:nth-child(1) {
  background-color: peachpuff;
}

.article-section article:nth-child(2) {
  background-color: azure;
}

.main-section {
  border: 2px solid black;
  border-radius: 30px;
  text-align: center;
  margin: 40px;
  padding: 40px;
}

#fixed-btn {
  position: fixed;
  top: 83vh;
  right: 20px;
  background-color: #9567f7;
  border-radius: 50%;
  height: 100px;
  width: 100px;
  cursor: pointer;
}

footer {
  background-color: white;
  font-weight: 200;
  padding: 30px;
  text-align: center;
}

@media screen and (max-width: 455px) {
  .article-section {
    flex-direction: column;
  }

  .article-section article {
    margin: 20px 20px;
  }

  nav {
    font-size: medium;
  }

  li {
    margin: 10px 20px;
  }

  .main-section {
    margin: 20px;
    padding: 20px;
  }

  #fixed-btn {
    height: 75px;
    width: 75px;

  }
}