style.css

#hero{
  background-image:
    radial-gradient(ellipse at center, rgba(0,0,0,0.3) 0%, rgba(0,0,0,0.9) 100%),
    url("/images/hero-4k.jpg");
    background-size:cover;
    background-position:center;
}

@media(max-width:1920px){
  #hero{
    background-image:
      radial-gradient(ellipse at center, rgba(0,0,0,0.3) 0%, rgba(0,0,0,0.9) 100%),
      url("/images/hero-1080.jpg");
    }
}

@media(max-width:640px){
  #hero{
    background-image:
      radial-gradient(ellipse at center, rgba(0,0,0,0.3) 0%, rgba(0,0,0,0.9) 100%),
      url("/images/hero-mobile.jpg");
    }
}

#hero .text.container{
  text-shadow:0 0 3em #000;
}
#hero .menu .logo.image{
  padding:0 0.5em 0 0;
}

/* past talks */
span.ui.avatar.image{
  background:#ccc;
}
.talk.title{
  position:absolute;
  bottom:0;
  right:0;
  left:0;
  display: flex;
  justify-content: flex-start;
  line-height:1em;
  align-items: flex-end;
  background:linear-gradient(to bottom, rgba(0,0,0,0) 0%,rgba(0,0,0,0.8) 2.5em);
  color:white;
  font-size:1.5rem;
  padding:2em 0.75em 0.5em;
}

.talk.placeholder{
  background: url("images/hero-mobile.jpg") no-repeat center;
  background-size:cover;
  padding-top:56%;
}

.card .resource{
  margin-right:1em;
}

.ui.horizontal.divider{
  padding:4em 0;
}

/* single talk pages */
.player-wrapper{
  position:relative;
  width:100%;
  padding-bottom:56.25%;
  margin-bottom:1em;
}
.player-wrapper iframe{
  position:absolute;
  left:0;
  top:0;
  width:100%;
  height:100%;
  z-index:10;
}
.player-wrapper .ui.segment{
  position:absolute;
  left:0;
  top:0;
  width:100%;
  height:100%;
  z-index:5;
  color:white;
}
.player-wrapper.no-video .active.dimmer{
  display: flex;
  justify-content:center;
  align-items:center;
}
/* misc */
.ui.card{
  width:auto;
  overflow:hidden;
  word-wrap: break-word;
}
.ui.vertical.stripe .card p{
  font-size:1em;
}

.home .masthead.segment {
  min-height: 700px;
  padding: 1em 0em;
}
.masthead .logo.item img {
  margin-right: 1em;
}
.masthead .ui.menu .ui.button {
  margin-left: 0.5em;
}
.home .masthead h1.ui.header {
  margin-top: 3em;
  margin-bottom: 0em;
  font-size: 4em;
  font-weight: normal;
  font-weight: bold;
}
body:not(.home) .masthead .text{
  display:none;
}
.masthead h2 {
  font-size: 1.7em;
  font-weight: normal;
}

.ui.vertical.stripe {
  padding: 5em 0em;
}
.ui.vertical.stripe h3 {
  font-size: 2em;
}
.ui.vertical.stripe .floated.image {
  clear: both;
}
.ui.vertical.stripe p {
  font-size: 1.33em;
}
.ui.vertical.stripe .horizontal.divider {
  margin: 3em 0em;
}

.quote.stripe.segment {
  padding: 0em;
}
.quote.stripe.segment .grid .column {
  padding-top: 5em;
  padding-bottom: 5em;
}

.footer.segment {
  padding: 5em 0em;
}

.secondary.pointing.menu .toc.item {
  display: none;
}

@media only screen and (max-width: 700px) {
  .ui.fixed.menu {
    display: none !important;
  }
  .secondary.pointing.menu .item,
  .secondary.pointing.menu .menu {
    display: none;
  }
  .secondary.pointing.menu .toc.item {
    display: block;
  }
  .home .masthead.segment {
    min-height: 350px;
  }
  .home .masthead h1.ui.header {
    font-size: 2em;
    margin-top: 1.5em;
  }
  .masthead h2 {
    margin-top: 0.5em;
    font-size: 1.5em;
  }
}