* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif
}

html {
  scroll-behavior: smooth;
}

body {
  display: flex;
  line-height: 1.6;
}

#navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 250px;
  height: 100%;
  background: #222;
  color: #fff;
  padding: 1rem;
  overflow-y: auto;
}

#navbar header {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  font-weight: bold;
}

#navbar .nav-link {
  display: block;
  color: #ddd;
  text-decoration: none;
  padding: 0.5rem 0;
}

#navbar .nav-link:hover {
  color: #fff;
}

#main-doc {
  margin-left: 260px;
  padding: 2rem;
  max-width: 800px;
}

section {
  margin-bottom: 2rem;
}

code {
  display: block;
  background: #94a3b8;
  padding: 0.5rem;
  margin: 0.5rem 0;
  border-radius: 4px;
}

ul {
  margin: 1rem 0 1rem 2rem;
}


/* Media Query */
@media (max-width: 768px) {
  body {
    flex-direction: column;
  }

  #navbar {
    position: relative;
    width: 100%;
    height: auto;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  #navbar .nav-link {
    padding: 0.5rem;
    border-bottom: 1px solid #444;
    width: 100%;
  }

  #main-doc {
    margin-left: 0;
    padding: 1rem;
  }
}