* {
  padding: 0;
  margin: 0;
  font-family: 'Roboto', sans-serif;
  text-decoration: none;
}

main {
  display: grid;
  grid-template-columns: repeat(16, 1fr);
  grid-template-rows: 10vh 50vh 5vh 35vh;
  background: #FEF9E7;

}

.page-loader {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  background-color: rgb(255, 255, 255);

  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 200;
  font-weight: 400;
}

.page-loader img {
  width: 8rem;
  height: 8rem;
}

/* Scroll 2 */
div::-webkit-scrollbar {
  width: 5px;
  height: 5px;
}

div::-webkit-scrollbar-track {
  background-color: rgba(0, 0, 0, 0.082);
  border-radius: 10px;
}

div::-webkit-scrollbar-thumb {
  background-color: #11171a75;
  border-radius: 10px;
}

/*=====================================================================*/
/* containers layout */
#selfintro-container {
  grid-column: 3/8;
  grid-row: 1/5;
  transition: opacity 0.25s ease-in-out;

  display: flex;
  flex-flow: column;
  justify-content: center;
  overflow-y: hidden;
  padding: 2% 2% 2% 2%;

  z-index: 20;
}

#threejs-container {
  grid-column: 8/17;
  grid-row: 1/5;

  overflow: hidden;
}

#highlight-overlay {
  grid-column: 8/17;
  grid-row: 1/5;
  overflow-x: hidden;

}

#about-me-container {
  grid-column: 3/8;
  grid-row: 1/5;
  overflow-y: hidden;
  transition: opacity 0.25s ease-in-out;
  padding: 2% 2% 2% 2%;
  z-index: 10;

}

#publications-container {
  grid-column: 3/8;
  grid-row: 1/5;
  overflow-y: hidden;
  transition: opacity 0.25s ease-in-out;
  padding: 2% 2% 2% 2%;
  z-index: 11;
}

.project-iframe-container {
  grid-column: 1/14;
  grid-row: 1/5;
  overflow-y: hidden;
}

.nav-bar {
  grid-column: 1/3;
  grid-row: 1/5;
  z-index: 15;

  display: flex;
  flex-flow: column;
  gap: 1.75rem;
  justify-content: center;
  padding-left: 2vw;
}

.sub-project-grid {
  grid-column: 3/8;
  grid-row: 1/5;
  height: 70vh;
   min-height: 0;

  align-self: center;
  opacity: 0;
  transition: opacity 0.25s ease-in-out;

  display: grid;
   grid-template-columns: repeat(4, minmax(0, 1fr));
   grid-auto-rows: clamp(140px, 11vw, 220px);
  gap: 0.6rem;
  overflow-y: auto;
   overflow-x: hidden;
  z-index: 20;

  padding: 2% 2% 2% 2%;
}

/*=====================================================================*/
/* nav-bar contents */

.nav-bar img {
  height: 8vh;
  width: 8vh;
  cursor: pointer;
}

.nav-bar img:hover {
  transform: scale(1.12);
}

.nav-bar>ul {
  display: flex;
  flex-flow: column;
  gap: 1rem;
  list-style: none;
  font-size: medium;
  font-weight: 300;
  cursor: pointer;
}

.nav-bar>ul>li:hover {
  color: rgb(255, 71, 71);
}

/* radio buttons */
.nav-bar>form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  list-style: none;
  font-size: medium;
  font-weight: 300;
}

.nav-bar label {
  cursor: pointer;

}

.nav-bar label:hover {
  color: rgb(255, 71, 71);
}

.nav-bar input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.nav-bar input:checked+span {
  color: rgb(255, 71, 71);
}

.link-div {
  display: flex;
  gap: 0.5rem;
}

.link-div img {
  opacity: .75;
  height: 1.25rem;
  width: 1.25rem;
}

/*=====================================================================*/
/* highlight overlay */

.highlight-div {
  position: absolute;
  width: 0.5rem;
  height: 0.5rem;

}

.highlight-rect {
  position: relative;
  background-color: rgb(255, 77, 77);
  width: 0.5rem;
  height: 0.5rem;
  transform: translate(0, 0);
  cursor: pointer;

}

.highlight-rect:hover {
  background-color: rgba(255, 77, 77, 0.596);
  transform: scale(2.5);
  transition: transform 0.25s ease-in-out;
}

.highlight-rect::before {
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: inherit;
  border-radius: 0;
  z-index: -1;
  animation: ripple 1.5s ease-out infinite;
}

@keyframes ripple {
  from {
    opacity: 1;
    transform: scale(0);
  }

  to {
    opacity: 0;
    transform: scale(6);
  }
}

/*=====================================================================*/
/* grid of the projects in different categories */

.grid-span-1 {
  grid-column-start: span 1;
  grid-row-start: span 1;
}

.grid-span-2 {
  grid-column-start: span 2;
  grid-row-start: span 1;
}

.grid-span-4 {
  grid-column-start: span 2;
  grid-row-start: span 2;
}

.hide-grid {
  visibility: hidden;
  opacity: 0;
}

/* project card */
.sub-project-grid img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-card {
  background-size: cover;
   background-position: center;
  transition: transform 0.25s ease;

}

.project-card:hover {
  transform: scale(1.03);
}

.project-card:hover .card-content {
  opacity: 1;
}

.card-content {
  background: rgba(255, 0, 0, 0.219);
  width: 100%;
  height: 100%;

  opacity: 0;
  display: flex;
  align-items: flex-start;
  flex-flow: column;
  gap: 1rem;
  justify-content: center;
  color: aliceblue;
  transition: opacity 0.25s ease-in-out;
  cursor: pointer;

}

.card-content div:first-child {
  font-size: medium;
  font-weight: 500;
  display: inline-block;
  align-self: center;
  text-align: center;
}

.card-content div:last-child {
  font-size: small;
  display: inline-block;
  align-self: center;
  text-align: center;

  border: 1px aliceblue;
  border-style: solid;
  border-radius: 1rem;
  padding: 0.1rem 0.5rem;
}



/*=====================================================================*/
/* content of self introduction container */
.greeting_div {
  display: flex;
  padding: 1rem 0;
}

.greeting_text {
  align-self: center;
  font-size: 3rem;
  font-weight: 200;
  /* background-color:aquamarine; */
}

.intro_text {
  /* background-color: antiquewhite; */
  font-weight: 300;
  line-height: 1.5;
  overflow-y: auto;
}

/*=====================================================================*/
/* sub project iframe */
iframe {
  border: none;
  width: 100%;
  height: 100%;
}

/*=====================================================================*/
/* sub project iframe */
.close {
  position: absolute;
  left: 32px;
  top: 32px;
  width: 32px;
  height: 32px;
  opacity: 0.8;
  cursor: pointer;
}

.close:hover {
  opacity: 1;
}

.close:before,
.close:after {
  position: absolute;
  left: 15px;
  content: ' ';
  height: 33px;
  width: 2px;
  background-color: #000000;
}

.close:before {
  transform: rotate(45deg);
}

.close:after {
  transform: rotate(-45deg);
}

/*=====================================================================*/
/* containers layout for Mobile Devices */
@media screen and (max-width:900px) {
  #selfintro-container {
    grid-column: 1/17;
    grid-row: 4/5;
    justify-content: start;

  }

  #threejs-container {
    grid-column: 1/17;
    grid-row: 1/4;

    overflow: hidden;
  }

  #highlight-overlay {
    grid-column: 1/17;
    grid-row: 1/4;
    overflow-x: hidden;

  }

  #about-me-container {
    grid-column: 1/17;
    grid-row: 4/5;

  }

  #publications-container {
    grid-column: 1/17;
    grid-row: 4/5;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .project-iframe-container {
    grid-column: 1/17;
    grid-row: 1/5;
    overflow-y: hidden;
  }

  .nav-bar {
    grid-column: 1/17;
    grid-row: 3/4;
    z-index: 15;

    flex-flow: column;
    gap: 1rem;
    justify-content: flex-end;
  }

  .sub-project-grid {
    grid-column: 1/17;
    grid-row: 4/5;
    height: 30vh;
     min-height: 0;
     grid-auto-rows: 110px;
  }

  .nav-bar>form {
    display: flex;
    flex-direction: row;
  }

}