html,
body {
  margin:0;
  padding:0;
  background:#f7f7f7;
  font-family:serif;
  min-width:800px;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

div.content {
  height:auto !important;
  min-height:100%;
  width:90%;
  max-width:1200px;
  margin:10px;

  align-self: center;
  justify-self: center;
  font-family:serif;
}

div.header {
  width:100%;
  height:12em;
  top:-8em;
  position:sticky;
  position:-webkit-sticky;
  left:0;
/*
  background-color:#004;
*/
  /*blue gradient*/
  background: rgb(2,0,36);
/*
  background: linear-gradient(165deg, rgba(2,0,36,1) 0%, rgba(9,7,83,1) 29%, rgba(0,153,255,1) 100%);
*/
  background-image:
    linear-gradient(165deg, rgba(2,0,3,1) 0%, rgba(9,7,13,.4) 50%, rgba(9,153,255,.8) 100%),
/*
    url("img/pexels-fatih-turan-63325184-12216829-scaled");
*/
/*
    url("img/pexels-spacex-586073-scaled3.jpg");
*/
    url("img/pexels-spacex-586056-scaled.jpg");
  background-size:cover;
  /*orange gradient*/
/*
  background: rgb(2,0,36);
  background: linear-gradient(24deg, rgba(2,0,36,1) 0%, rgba(83,13,7,1) 38%, rgba(255,177,0,1) 100%);
*/
}

img.logo {
  top:-85px;
  left:10px;
  position:absolute;
/*
  mix-blend-mode:difference;
*/
/*
  color:black;
*/
/*
  float:left;
*/
  margin:10px;
  margin-right:5px;
  height:160px;
/*
  vertical-align:middle;
*/
  z-index:10;
}

div.header img.background {
  width:100%;
  height:12em;
  justify-content:center;
  align-items:center;
  object-fit:cover;
  object-position:100% 65%;
}

div.header span {
  position:absolute;
  font-weight:bold;
  color:#eee;
  font-size:250%;
  margin:5px 10px;
/*
  backdrop-filter: blur(6px);
*/
  font-family:sans;
/*
  margin-left:125px;
*/
}

div.footer {
  width:100%;
  height:150px;
  left:0;
  background-color:#000;
  background-image:url("img/earth_space-footer_2000.jpg");
  background-position: top -90px right 10px;
  background-repeat:no-repeat;
/*
  background-image:url("img/pexels-gozde-ka-1173272892-27059615-scaled");
*/
/*
  background-image:url("img/pexels-spacex-586073-scaled3.jpg");
*/
/*
  background-size:cover;
  background-position: top -200px right 10px;
  background-repeat:no-repeat;
*/
  clear:both;
  color:#fff;
  margin-top: auto;
  font-size:80%;
  vertical-align:bottom;
  font-family:sans;
}

div.footer div.backdrop {
/*
  background:rgba(0, 0, 0, .3);
*/
  background:rgba(0, 0, 0, .5);
  width:100%;
  height:100%;
}

div.footer div.footer_left {
  display:block;
  float:left;
  width:45%;
  margin:10px 25px;
  font-family:inherit;
}

div.footer div.footer_right {
  display:block;
  float:right;
  width:30%;
  margin:10px 25px;
  text-align:right;
  font-family:inherit;
}

div.footer a {
  color:#fff;
}

div.footer a:hover {
  color:#fc0;
}

nav {
  background-color:rgba(255, 255, 255, .7);
  width:100%;
  height:3em;
  position:sticky;
  position:-webkit-sticky;
  top:.5em;
  display:flex;
  justify-content:center;
  align-items:center;
  box-shadow:0 0 .5em #000;
  margin-top:-4em;
  vertical-align:middle;
}

nav a {
  display:inline-block;
  float:left;
/*
  min-width:40px;
*/
  height:1.5em;
  transition:border-bottom .1s ease, height .1s ease;
  padding:10px 20px;
  margin:0;
  font-family:sans;
  font-size:120%;
  color:#000;
  text-decoration:none;
  font-weight:bold;
  white-space:nowrap;
}
nav a:hover {
/*
  border-bottom: .3em solid #9f7;
*/
  border-bottom: .3em solid #fc0;
/*
  border-bottom: .3em solid #09f;
*/
  height:1.2em;
  background-color:rgba(255, 255, 255, .7);
}

nav a.active {
/*
  border-bottom: .3em solid #f7f7f7;
*/
  border-bottom: .3em solid rgba(255, 204, 0, .7);
  background-color:rgba(255, 204, 0, .7);
/*
  background:linear-gradient(24deg, rgba(2,0,36,1) 0%, rgba(9,7,83,1) 39%, rgba(0,153,255,1) 100%);
*/
/*
  color:#fff;
*/
  height:1.2em;
  transition:border-bottom .1s ease, height .1s ease;
}


/*
 * Bibliography list
 */
ol.biblist {
  counter-reset:list;
  padding-left:0px
}
ol.biblist > li {
  list-style:none;
}
ol.biblist > li:before {
  content:"[" counter(list) "] ";
  counter-increment:list;
}

ul.biblist {
/*
  font-family:serif;
*/
}

ul.biblist span.type {
  font-weight:bold;
  color:#00a;
  margin-right:1ex;
}


ul.biblist span.title {
  font-weight:bold;
/*
  font-style:italic;
*/
/*
  color:#00a;
*/
}

ul.biblist span.self {
/*
  text-decoration:underline;
*/
}

table.events {
  border-spacing:0;
  margin:0;
  padding:0;
  text-align:left;
  width:100%;
}

table.events tr {
  margin:0;
  padding:0;
  vertical-align:top;
}

table.events tr:hover {
  background:#ddd;
}

table.events tr th {
  margin:0;
  padding:2px 5px;
  background:#ccc;
}

table.events td {
  margin:0;
  padding:2px 5px;
  vertical-align:top;
}

table.events tr td.time {
  font-weight:bold;
  color:#00a;
  width:100px;
  white-space: nowrap;
}

h1, h2, h3, h4, h5, h6 {
  font-family:sans;
}

h2 {
  border-bottom:2px solid #000;
  width:100%;
}

h3 {
  border-bottom:1px solid #777;
  width:100%;
}

[id]::before {
  content:'';
  display:block;
  height:75px;
  margin-top:-75px;
  visibility:hidden;
}