div.main_div {
  margin-left: 20px;
  margin-right: 30px;
  margin-top: 25px;
  padding: 10px;
  min-height: 240px;
  background-color: white;
  border-color: #111111;
  border-width: 3px;
  border-style: solid;
  border-radius: 5px;
  opacity: 0.9;
}
img.header_img {
  display: block;
  float: left;
  padding-right: 15px;
}
footer {
  text-align: center;
  font-size: 0.75em;
  padding: 10px;
  margin-top: 30px;
  margin-left: 20px;
  margin-right: 30px;
  background-color: white;
  border-color: #111111;
  border-width: 3px;
  border-style: solid;
  border-radius: 5px;
  opacity: 0.9;
}
code {
  background-color: black;
  color: lawngreen;
  padding: 5px;
  margin-top: 5px;
  margin-bottom: 5px;
}
small {
  margin-left: 15px;
}
nav {
  padding-top: 10px;
  margin-top: 30px;
  margin-left: 20px;
  margin-right: 30px;
  min-height: 45px;
  background-color: white;
  border-color: #111111;
  border-width: 3px;
  border-style: solid;
  border-radius: 5px;
  opacity: 0.9;
}
nav ul {
  list-style-type: none;
  margin-top: 0px;
  padding-top: 0px;
  padding-left: 10px;
}
nav li {
  float: left;
  margin-top: 0px;
  /*display: inline;*/
}
nav li a {
  display: block;
  text-decoration: none;
  padding: 5px;
  margin-top: 0px;
  /*text-indent: 5px;*/
}
nav li a[aria-current="page"] {
  background-color: #dedede;
}

body {
  background-size: 30px 30px;
  background-image:
  linear-gradient(to right, #00d8fd 1px, transparent 1px),
  linear-gradient(to bottom, #00d8fd 1px, transparent 1px);
}

aside {
  padding: 15px;
  margin-left: 30px;
  margin-right: 30px;
  background-color: #dedede;
}