body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  background-color: #f4f4f4;
}

header {
  background: #35424a;
  color: #ffffff;
  padding: 20px 0;
  text-align: center;
}

.back-to-top {
  position: fixed;
  bottom: 70px;
  right: 20px;
  display: none;
  background-color: #35424a;
  color: #fff;
  padding: 10px;
  border-radius: 10%;
  cursor: pointer;
  font-size: 25px;
}

.footer {
  background-color: #35424a;
  color: white;
  text-align: center;
  padding: 2px;
  position: fixed;
  bottom: 0;
  width: 100%;
}

.container {
  width: 80%;
  margin: auto;
  overflow: hidden;
  padding-bottom: 100px;
}

.module-section {
  background: #ffffff;
  padding: 20px;
  margin: 20px 0;
  border-radius: 5px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.module-header {
  display: flex;
  align-items: center;
}

h1,
h2,
h3 {
  color: #35424a;
}

ul {
  list-style-type: none;
  padding: 0;
}

ul li {
  margin: 10px 0;
}

a {
  text-decoration: none;
  color: #35424a;
}

a:hover {
  color: #e8491d;
}

.back-link {
  display: inline-block;
  margin: 20px 0;
  color: #35424a;
}