.header {
    overflow: hidden;
    background-color: transparent;
    position: sticky;
    top: 0;
    z-index: 2;
    transition: all 0.3s;
    height: 80px;
    color: white;
    display: flex;
    justify-content: space-between; 
    align-items: center; 
    font-family: 'Roboto', sans-serif;
    transition: background-color 0.5s ease, height 0.5s ease, color 0.5s ease;
    width: 100%;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
    color: #000000;

    font-family: 'Roboto', sans-serif;

    color: #4a4a4a;  

    font-weight: 300;  
    line-height: 1.5;  

    font-size: 18px;
}

p { 
  font-size: 18px;
}

.logo {
    position: relative;
    height: 50px;
    width: 400px;
    overflow: hidden;
}

.logo-img {
    position: absolute;
    top: 0;
    left: 0;
    height: 50px;
    transition: opacity 0.5s ease;
    padding-left: 40px
}

#logoImg1 {
    opacity: 1;
}

#logoImg2 {
    opacity: 0;
}


.nav-links {
    display: flex; 
}

.nav-links a {
    display: block;
    color: inherit;
    text-align: center;
    padding: 28px 20px;
    text-decoration: none;
    font-size: 16px;
}

/* hides burger icon on wider screen widths*/
.nav-links .icon {
  display: none;
}

@media screen and (max-width: 1100px){ 

  /*Only displays the burger icon if responsive class is not on */
  .nav-links:not(.responsive) a:not(.icon){
  display: none;}

  .nav-links a.icon {
    display: flex;
  }

  /* Allows all the links to be visible */
  .header{
    overflow: visible !important;
  }

  /* Styles the entire dropdown format */
  .nav-links.responsive{
    position: absolute;
    top: 80px;
    display: flex;
    right: 0;
    left: 0;
    flex-direction: column;
    z-index: 1000;
    background-color:rgba(166, 166, 166, 0.5) ;
    max-width: 100%;
  }

  /* Styles individual nav-links in dropdown format */
  .nav-links.responsive a {
    position: static;
    display: block;
    width: auto;
    text-align: left;
    padding: 16px 20px;
  }

  .nav-links a.icon{
    text-align: center;
  }
}

.image-container {
    position: relative;
    z-index: 1;
    margin-top: -80px; 
    width: 100%;  
}

.image-container img {
    width: 100%;
    height: 430px;
    object-fit: cover;

}

/* SPACING BETWEEN SECTIONS*/

.separation{
  padding: 1rem;
}

/* PUBLICATIONS AND TALKS HERO IMAGE*/
.centered-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-family: 'Roboto', sans-serif;
    font-weight: 3400;
}

.centered-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 36px;
  color: WHITE;
  font-family: 'Roboto', sans-serif;
  background-color: rgba(166, 166, 166, 0.5); 
  padding: 10px 20px; 
  border-radius: 0px; 
  text-align: center;
}

.image-container {
  position: relative;
}

/* WHITEPAPER SECTION*/
.whitepaper-container {
  margin: 0 auto;
  padding: 0 30px;
}

.whitepaper h1{
  text-align: center;
  font-family: 'Roboto', sans-serif;
  color: black;
  font-weight: 300;
}

.whitepaper a{
  text-align: center;
  text-decoration: none;
}

/* PUBLICATIONS CONTAINER */
.publications-container {
    margin: 0 auto; 
}

.publications h1 {
    text-align: center;
    font-family: 'Roboto', sans-serif;  
    color: #000000;
    font-weight: 300;
  }

.publications a{
  text-decoration: none;
}

.publications{
  padding: 0 30px;
}

.publications-article-padding{
    margin: 0 auto;
    padding-bottom: 1rem; 
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;  
  max-width: calc(100% - 40px);  
  padding-left: 100px;  
  padding-right: 0px;  
}

.grid-item {
  width: 200px;
  height: auto;
}

/* TALKS SECTION */
.talks-container {
    margin: 0 auto;
    padding: 0 30px; 
}

.talks h1 {
    text-align: left;
    font-family: 'Roboto', sans-serif;
    font-weight: 300;  
}

.talks-grid-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    justify-items: center;  
}

@media screen and (max-width: 800px){
  .talks-grid-container {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

.talks-grid-item {
    width: 100%;  
    height: auto;
    box-sizing: content-box;
}


.talks-thumbnail {
    width: 100%;
    height: 20rem;
    cursor: pointer;
    box-shadow: 0px 4px 8px rgba(0, 0, 0, 0.1);
}
.talks-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Style for the overlay */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.5s ease;
  overflow: hidden;
}

/* Style for the expanded image */
.overlay img {
  max-width: 90%;
  max-height: 90%;
  cursor: zoom-in;
}

.overlay img.zoomed {
  position: fixed;
  cursor: move;
  transform: scale(2);
}

/* Class to show the overlay */
.overlay.show {
  visibility: visible;
  opacity: 1;
}



/* img:active {
  position: fixed;
  top: 50%;
  left: 70%;
  transform: translate(-50%, -50%) scale(2); 
} */

.talks-thumbnail:hover {
    transform: scale(1.1);
    box-shadow: 0px 6px 12px rgba(0, 0, 0, 0.2);
}

.talks-text {
    color: #000000;
    text-align: center;  
    font-size: 14px;  
    line-height: 1.5;  
    padding-top: 10px;  

    font-family: 'Roboto', sans-serif;

    font-weight: 300;
}

.talks h1 {
  font-weight: 300;
  text-align: center;
}

/* FOOTER */

.footer-container {
    background-color: #d7345d;
    width: 100%;
    margin-top: 40px;
  }
  
  .custom-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px; 
  }
  
  .footer-left,
  .footer-middle,
  .footer-right {
    flex: 1;
    text-align: center;
  }
  
  .footer-logo {
    max-width: 300px; 
    height: auto;
  }