body{
  font-family: Arial, Helvetica, sans-serif;
  font-size: 20px
}

#nav-placeholder>ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #3385ff;
}

#nav-placeholder li {
  float: left;
}

 #nav-placeholder li a {
  display: block;
  color: white;
  text-align: center;
  padding: 14px;
  text-decoration: none;
}
#nav-placeholder img{
  display: block;
  margin-left: auto;
  margin-right: auto;
  padding: 8px;
}

#nav-placeholder li:hover {
  background-color: #1066;
}

#whole_body img{
  display: block;
  margin-left: auto;
  margin-right: auto;
}
#pdfin li{
  padding: 4px;
}

p{
  display: block;
  margin-left: 20px;
  margin-right: 20px;
}