html {
  height: 100%;
  display: table;
  margin: auto;
}

body {
  height: 100%;
  display: table-cell;
}

img {  vertical-align: middle; }

span {
  display: inline-block;
  vertical-align: middle;
}

h1 {
  font-size:1.5em;
}

h2 {
  font-size:1.2em;
}

.title_bar {
  padding: 0.5em;
  padding-top: 0.5em;
  border-top-style: solid;
  border-top-width: 0.3em;
  border-top-color: darkblue;
  border-bottom-style: solid;
  border-bottom-width: 0.3em;
  border-bottom-color: darkblue;
  background-image: url(/images/titleplaneengine.png);
  background-repeat: no-repeat;
  background-position: top right;
}

 /* unvisited link */
a:link {
  color: black;
  text-decoration: none;
  font-weight:bold;
}

/* visited link */
a:visited {
  color: black;
}

/* mouse over link */
a:hover {
  color: grey;
}

/* selected link */
a:active {
  color: grey;
} 

.title_link {
  font-size:1.25em;
  margin-left:2em;
}

.nav-link { color: grey; font-size: 1em; padding-left: 3em;}
.text-muted { color: grey; font-size:.75em; }

#nav_top_border {
  border-top-style: solid;
  border-top-width: 0.5em;
  border-top-color: darkblue;
}

#nav_bottom_border {
  //border-top-style: solid;
  //border-top-width: 0.5em;
  //border-top-color: darkblue;
}

#sitelogo {
  float:left;
  margin-bottom: 1em;
}

#logotext {
  margin-left: 0.4em;
  margin-top: 0.4em;
  margin-bottom: 0.2em;
  font-size:1.75em;
  color: darkblue;
}

#footer_div {
  margin:2em;
}

#wrapper {
  margin-top: 2em;
}

#mainbox {
  display: flex;
  max-width: 800px;
}

#left {
  flex: 0 0 50%;
  text-align: center;
}

#right {
  flex: 1;
  text-align: center;
}

#footer_div {
  text-align: center;
}

.content_div {
  margin: 1em;
  margin-top 2em;
  max-width: 750px;
}

.button {
  background-color: #1c87c9;
  border: none;
  color: white;
  padding: 20px 25px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 20px;
  margin: 4px 2px;
  cursor: pointer;
}

#bptech {
  width:200px;
  float:right;
  margin:0.25em;
  padding-left: 0.25em;
  border-style: solid;
  border-width: 3px;
  border-color: darkblue;
  background-image: url(/images/spinningturbine.svg); background-repeat: no-repeat;
  //background-attachment: fixed;
  background-position: top right; background-size: 300px 300px;
}