body {
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  font-family: sans-serif;
  min-height: 100vh;
}

header {
  position: relative;
  height: 25vw;
  overflow: hidden;
}

.header-video {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  min-width: 100%;
  min-height: 100%;
}

.header-title {
  position: absolute;
  top: 25%;
  left: 5%;
  font-weight: 900;
  font-size: 8vw;
  line-height: 1;
  -webkit-text-stroke: 2px white;
  opacity: 0.9;
  color: transparent;
  margin-left: 10vw;
  background-clip: text;
  -webkit-background-clip: text;
  background-image: linear-gradient(to bottom, transparent 50%, black 50%);
  transition: background-position ease-out 0.4s;
  background-size: 1% 200%;
}

.header-subtitle {
  position: absolute;
  bottom: 10%;
  right: 15%;
  font-weight: 900;
  font-size: 5vw;
  -webkit-text-stroke: 2px black;
  color: transparent;
}

.header-title:hover {
  background-position: 0 -100%;
}

.group-element {
  margin: 4em 0;
}

footer {
  bottom: 0;
  text-align: center;
  background-color: black;
  color: white;
  padding: 20px;
}

.copyright {
  font-size: 12px;
}

.email-link {
  color: white;
  text-decoration: none;
}

h1 {
  text-align: center;
  font-weight: 900;
  font-size: 1.7vw;
  margin-bottom: 1em;
}

.youtube-video iframe {
  margin: 0 auto;
  display: block;
  aspect-ratio: 16 / 9;
  width: 70%;
  height: 100%;
}

.presentation-text {
  margin: 10px 20%;
  text-align: justify;
  text-justify: auto;
}

.presentation-text-signature {
  text-align: left;
  margin-left: 85%;
  margin-top: 3em;
}




/* Image grid */
.row {
  display: flex;
  flex-wrap: wrap;
  padding: 0 4px;
  justify-content: center;
}



.column img {
  margin-top: 40px;
  vertical-align: middle;
  width: 80%;
}

.gallery-image{
  text-align: center;
}

/* Create four equal columns that sits next to each other */
.column {
  flex: 25%;
  max-width: 30%;
  padding: 0 0px;
}

/* Responsive layout - makes a two column-layout instead of four columns */
@media screen and (max-width: 1000px) {
  .column {
    flex: 60%;
    max-width: 60%;
  }
}


/* Responsive layout - makes the two columns stack on top of each other instead of next to each other */
@media screen and (max-width: 800px) {
  .column {
    flex: 80%;
    max-width: 80%;
  }
}