html {
  scroll-behavior: smooth;
  overflow-x: hidden;
}

* {
  margin: 0px;
  padding: 0px;
}

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background-color: rgb(235, 235, 235);
}

::-webkit-scrollbar-thumb {
  border-radius: 111px;
  background: var(--titleColor);
}

body {
  background-color: rgb(255, 255, 255);
  overflow: hidden;
}

::selection {
  background-color: black;
  color: rgb(255, 255, 255);
}

:root {
  --titleColor: #20252b;
  --textColor: #575e65;
}

h1, h2, h3, h4, h5, h6, p, ul, li, a {
  margin: 0px;
  padding: 0px;
}

h1, h2, h3, h4, h5, h6 {
  font-family: Nunito, sans-serif;
  color: var(--titleColor);
}

section {
  padding-bottom: 80px;
}

p {
  font-family: Arimo, sans-serif;
  color: var(--textColor);
}

.top-header {
  padding: 20px 0px;
  position: relative;
  z-index: 99;
}

.mobile_menu {
  display: none;
}

.mobile_menu .nav-link {
  background: black;
  border-bottom: 1px solid white;
  width: 40px;
  height: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  color: rgb(255, 255, 255);
}

.mobile_menu .nav-link:last-child {
  border-bottom: none;
}

.mobile_menu .navbar-collapse {
  position: absolute;
  top: 65px;
  right: 10px;
}

.navbar_nav {
  display: flex;
  justify-content: end;
}

.toggle {
  position: relative;
  width: 60px;
  height: 50px;
  background: transparent;
  box-shadow: none;
  border-radius: 10px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  overflow: hidden;
  color: rgb(32, 37, 43);
}

.toggle span {
  position: absolute;
  width: 35px;
  height: 4px;
  background: black;
  border-radius: 10px;
  transition: 0.5s;
  left: 15px;
}

.toggle span:nth-child(1) {
  transform: translateY(-15px);
  width: 20px;
  left: 15px;
}

.toggle.active span:nth-child(1) {
  width: 40px;
  transform: translateY(0px) rotate(45deg);
  transition-delay: 0.125s;
  background: rgb(32, 37, 43);
}

.toggle span:nth-child(2) {
  transform: translateY(15px);
  width: 15px;
  left: 15px;
}

.toggle.active span:nth-child(2) {
  width: 40px;
  transform: translateY(0px) rotate(315deg);
  transition-delay: 0.25s;
  background: rgb(32, 37, 43);
}

.toggle.active span:nth-child(3) {
  transform: translateX(60px);
}

.navbar-toggler {
  border: none;
}

.navbar-toggler:focus {
  box-shadow: none;
}

.logo a {
  font-weight: 700;
  font-size: 24px;
  text-decoration: none;
  color: black;
}

.top-header ul {
  column-gap: 24px;
}

.top-header ul li {
  list-style: none;
}

.top-header ul li a, .footer_social_link a {
  background-color: black;
  width: 40px;
  height: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  border-radius: 100px;
  text-decoration: none;
  transition: 0.2s ease-out;
  color: #fff;
}

.top-header ul li a:hover {
  border: 1px solid black;
  background-color: transparent;
}
.top-header ul a i {
  color: rgb(255, 255, 255);
  font-size: 1.5rem;
  transition: 0.2s ease-out;
}

.top-header ul a:hover i {
  color: black;
}
.banner {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 90vh;
}

.banner_subTitle {
  color: rgb(168, 168, 168);
  text-align: center;
  font-size: 48px;
  font-weight: 500;
  z-index: 1;
}

.banner_title {
  color: black;
  font-size: 200px;
  font-weight: 700;
  text-align: center;
  animation-name: banner-animation;
  animation-duration: 3.8s;
  animation-iteration-count: 1;
  animation-timing-function: linear;
}

@keyframes banner-animation {
  0% {
      text-shadow: rgb(170, 170, 170) -15px 12px;
  }

  50% {
      text-shadow: rgb(170, 170, 170) 20px 12px;
  }

  100% {
      text-shadow: rgb(170, 170, 170) 0px 0px;
  }
}

.banner_title span {
  color: rgb(217, 217, 217);
  text-shadow: none;
}

.banner_content p {
  font-size: 1.375rem;
}

.projects {
  margin-bottom: 50px;
}

.project-section {
  margin-top: -120px;
}

.banner-image img:first-child {
  position: absolute;
  top: -73px;
  left: 70px;
  max-width: 480px;
  z-index: 2;
}

.banner-image img:last-child {
  position: absolute;
  top: -125px;
  right: 30px;
  max-width: 520px;
  z-index: -1;
}

.banner_two {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.banner_two h3 {
  color: rgb(27, 255, 7);
  font-weight: 700;
  font-size: 30px;
  text-align: center;
}

.banner_two h1 {
  font-size: 200px;
  text-align: center;
  color: black;
  font-weight: 800;
}

.banner_two h1 span {
  color: rgb(217, 217, 217);
}

.banner_two img {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation: auto ease 0s 1 normal none running none;
}

@keyframes banner-two-animation {
  0% {
      transform: translate(-50%, -50%) rotate(10deg);
  }

  100% {
      transform: translate(-50%, -50%) rotate(0deg);
  }
}

.our_people h1 {
  font-size: 5.25rem;
  margin-bottom: 66px;
  font-weight: 500;
}

.section_title h2 {
  font-size: 4rem;
  position: relative;
  margin-bottom: 30px;
  padding-bottom: 5px;
}

.section_title h2::after {
  content: "";
  width: 100%;
  height: 1px;
  background: rgb(52, 61, 70);
  position: absolute;
  left: 0px;
  bottom: 0px;
}

.our_padding {
  padding: 0px;
}

.portfolio-link {
  display: inline-flex;
  justify-content: center;
  gap: 5px;
  align-items: center;
}

.portfolio-link a {
  text-align: center;
  text-transform: capitalize;
  font-size: 1.125rem;
  text-decoration: none;
  color: var(--titleColor);
  font-weight: 600;
}

.postdocs_content h3 {
  font-size: 2.5rem;
  font-weight: 700;
}

.postdocs_content h4 {
  font-size: 1.75rem;
  margin: 10px 0px;
}

.postdocs_content p {
  font-size: 1.375rem;
  max-width: 545px;
  margin-bottom: 2rem;
}

.personal_website_link {
  color: var(--titleColor);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 700;
  position: relative;
  padding-bottom: 4px;
}
/* .single_student_card .personal_website_link{
  border-bottom: 1px solid #20252b;
}
.single_student_card .personal_website_link:hover::after{
  width: 0;
} */
.personal_website_link::after {
  position: absolute;
  content: "";
  background: var(--titleColor);
  height: 1px;
  width: 0%;
  bottom: 0px;
  left: 0px;
  transition: 0.4s ease-out;
}

.personal_website_link:hover::after {
  width: 100%;
}

.secound_row_position {
  top: -70px;
}

.postdocs_img_position {
  left: -120px;
}

.phd {
  margin-bottom: 80px;
}

.single_student_card h3 {
  font-weight: 400;
  font-size: 1.6rem;
  margin: 10px 0px;
}
.owl-carousel .owl-stage-outer{
  padding-bottom: 10px !important;
}
.phd  .owl-nav {
  position: absolute;
  bottom: -70px;
  right: 30px;
  display: flex;
  column-gap: 15px;
  display: inherit !important;
}

.phd .owl-nav button {
  display: inline-block;
  width: 40px;
  height: 40px;
  border-radius: 100px;
  background: var(--titleColor) !important;
  color: white !important;
  font-size: 22px !important;
}

.phd .owl-nav button:hover {
  border: 1px solid var(--titleColor);
  color: var(--titleColor) !important;
  background-color: transparent !important;
}

/* .phd .owl-carousel .owl-stage-outer {
  height: 515px;
} */

.publications .section_title h2::after, .recent .section_title h2::after, .academic .section_title h2::after, .teaching .section_title h2::after, .work .section_title h2::after, .projects .section_title h2::after, .news .section_title h2::after {
  display: none;
}

.publication_content {
  max-width: 700px;
}

.publication_content h3 {
  font-size: 2rem;
  line-height: 45px;
}

.publication_content p {
  margin: 20px 0px;
  font-size: 1.375rem;
}

.publication_content_one {
  margin-left: 60px;
}

.cusotm_row_gap {
  margin-bottom: 100px;
}

.btn_view {
  background: transparent;
  border: 1px solid var(--titleColor);
  padding: 12px 25px;
  color: var(--titleColor);
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 15px;
  margin: 70px auto 0px;
  transition: 0.125s ease-out;
}

.btn_view:hover {
  transform: scale(0.95);
}

.rec_content ul {
  display: flex;
}

.rec_content ul li:first-child {
  margin-left: 0px;
}

.rec_content ul li {
  list-style: none;
  margin-left: -15px;
}

.rec_content h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 30px;
  font-family: "Arimo", serif;
}

.rec_content p {
  font-size: 1.375rem;
  line-height: 30px;
  max-width: 700px;
  font-family: "Arimo", serif;
}

.mb_30 {
  margin-bottom: 30px;
}

.padding_left_right {
  padding: 0px 80px;
}

.recent_carousel .owl-nav .owl-prev {
  top: 50%;
  transform: translateY(-50%);
  left: -70px;
  width: 40px;
  height: 40px;
  border-radius: 100px;
  transition: 0.3s ease-out;
  position: absolute !important;
  background: transparent !important;
  color: var(--titleColor) !important;
  font-size: 20px !important;
}

.recent_carousel .owl-nav {
  display: block !important;
}

.recent_carousel .owl-nav .owl-next {
  top: 50%;
  transform: translateY(-50%);
  right: -70px;
  width: 40px;
  height: 40px;
  border-radius: 100px;
  transition: 0.3s ease-out;
  position: absolute !important;
  background: transparent !important;
  color: var(--titleColor) !important;
  font-size: 20px !important;
}

.recent_carousel .owl-nav .owl-next:hover, .recent_carousel .owl-nav .owl-prev:hover {
  background: black !important;
}

.recent_carousel .owl-nav .owl-prev:hover i, .recent_carousel .owl-nav .owl-next:hover i {
  color: white !important;
}

.single_produtc {
  text-align: center;
}

.single_produtc h4 {
  font-size: 1.65rem;
  font-weight: 600;
  margin: -20px 0px 20px;
}

.single_produtc a {
  background: transparent;
  border: 1px solid var(--titleColor);
  border-radius: 100px;
  padding: 13px 25px;
  display: block;
  width: 95%;
  margin: auto;
  text-decoration: none;
  font-size: 1.1rem;
  font-weight: 700;
  transition: 0.3s ease-out;
  color: var(--titleColor);
}

.product_btn:hover {
  background-color: var(--titleColor);
  color: rgb(255, 255, 255);
}

.teaching .accordion-button::after {
  background-size: initial;
  background-attachment: initial;
  background-origin: initial;
  background-clip: initial;
  background-color: transparent;
  width: 40px;
  height: 40px;
  background-repeat: no-repeat;
  background-position: center center;
  border-radius: 100px;
  content: '\2b';
  font-family: 'Font Awesome 6 Free';
   background-image: none;
   font-size: 30px;
   text-align: center;
   padding-top: 2px;
}
.teaching .accordion-button:not(.collapsed)::after {
  background-image: url(../images/minus-sign.png);
  content: "";
  background-size: 30px;
}


.teaching .accordion-button:focus {
  z-index: 3;
  outline: 0px;
  box-shadow: none;
}

.custom_border {
  border-top: 1px solid;
  padding: 20px 0px;
}

.custom_border:last-child {
  border-bottom: 1px solid black;
}

.teaching .section_title {
  margin-bottom: 50px;
}

.teach_accor_image img {
  max-height: 140px;
}

.teaching .accordion-button:not(.collapsed) {
  background-color: transparent;
  box-shadow: none;
}

.teaching .accordion-item:last-of-type > .accordion-.top-header .accordion-button.collapsed, .accordion-item:first-of-type > .accordion-.top-header .accordion-button {
  border-radius: 0px;
  padding: 0px;
}

.teach_card h2 {
  font-size: 2.2rem;
  font-weight: 700;
}

.teach_card h1 {
  font-size: 4.2rem;
  font-weight: 500;
}

.work_body {
  margin-top: 60px;
}

.work .accordion-button:focus {
  box-shadow: none;
}

.work .accordion-button:not(.collapsed) {
  background-color: transparent;
  box-shadow: none;
}

.work .accordion-item {
  border: none;
}

.work .accordion-button {
  padding: 0px;
  border-bottom: 2px solid rgba(52, 61, 70, 0.537);
}

.acco_primary_title {
  font-size: 3rem;
  padding-bottom: 15px;
}

.work .accordion-item:last-of-type > .accordion-.top-header .accordion-button.collapsed {
  border-radius: 0px;
}

.accordion_body_title {
  font-size: 2rem;
  font-weight: 700;
  margin: 30px 0px 5px;
}

.accordion_body_text {
  font-size: 1.25rem;
}

.accordion_body_top_.top-header {
  font-size: 2rem;
  font-weight: 700;
  margin: 30px 0px 20px;
}

footer {
  border-top: 2px solid rgba(32, 37, 43, 0.494);
  overflow: hidden;
}

.primary_footer {
  padding-top: 75px;
  padding-bottom: 85px;
}

.footer_card_text {
  font-size: 1.25rem;
}

.footer_card_title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 45px;
}

.f_link {
  text-decoration: none;
  font-weight: 700;
  color: var(--titleColor);
  padding-bottom: 3px;
}

.f_link_wrap {
  display: flex;
  align-items: center;
  column-gap: 10px;
  margin-top: 45px;
  width: fit-content; 
}

.footer_content_profile {
  display: flex;
  column-gap: 20px;
}

.f_left_img {
  width: 55px;
}

.f_right_content {
  width: auto;
}

.f_right_content h2 {
  font-size: 1.6rem;
  font-weight: 400;
  margin-top: 10px;
}

.footer_social_link {
  display: flex;
  column-gap: 15px;
}

.footer_social_link li {
  list-style: none;
}

.footer_social_link li a {
  text-decoration: none;
}
.footer_social_link li a:hover{
  border: solid 1px #20252b;
  background: #fff;
  color: #20252b;
}
.footer_social_link li a i{
  font-size: 1.5rem;
  transition: 0.2s ease-out;
}

.footer_social_link li a:hover i{
  color: #20252b;
}
/* .footer_social_link li a i {
  color: var(--titleColor);
  font-size: 42px;
} */

.footer_content_address {
  margin-top: 33px;
}

.footer_content_address li {
  list-style: none;
  line-height: 40px;
}

.footer_content_address p {
  font-size: 1.25rem;
}

.f_right_content .f_link_wrap {
  margin-top: 20px;
}

.secondary_footer {
  padding: 30px 0px;
  border-top: 1px solid rgba(32, 37, 43, 0.494);
  font-size: 1.25rem;
}

.news_card {
  padding: 10px 20px;
  border: 1px solid var(--textColor);
  margin-bottom: 30px;
}

.news_card span {
  display: block;
  text-align: end;
  color: var(--textColor);
  font-family: Nunito, sans-serif;
}

.news_card p {
  font-size: 1.4rem;
  color: var(--titleColor);
  margin: 10px 0px 20px;
}

.news_card a {
  text-decoration: none;
  color: var(--titleColor);
  display: inline-flex;
  gap: 15px;
  align-items: center;
  font-weight: 700;
  text-transform: capitalize;
  padding-bottom: 2px;
}

.hover_line{
  position: relative;
}
.hover_line::before{
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  height: 1px;
  width: 0%;
  background-color: #20252b;
  transition: .4s all ease-in-out;
}
.hover_line:hover::before{
  width: 100%;
}

.projects .accordion-item:hover .accordion-button::after{
  background-color: black !important;
  color: #fff;
}
.works .accordion-item:hover .accordion-button::after{
  background-color: #fff;
}

.secondary_footer a{
  color: #20252b;
  text-decoration: none;
  text-align: right;
  font-size: 18px;
  cursor: pointer;
  font-weight: 500;
}
.teaching .accordion-body p{
  font-size: 1.75rem;;
}
.teaching .accordion-button{
  padding: 0;
}

/* professors carousel css  */
.professors_carousel.owl-carousel .owl-nav{
  display: contents;
}
.professors_carousel.owl-carousel .owl-nav .owl-next{
  display: inline-block;
  width: 40px;
  height: 40px;
  border-radius: 100px;
  background: var(--titleColor) !important;
  color: white !important;
  font-size: 22px !important;
  top: 50%;
  right: -60px;
  transform: translateY(-50%);
  position: absolute;
}
.professors_carousel.owl-carousel .owl-nav .owl-next:hover, .professors_carousel.owl-carousel .owl-nav .owl-prev:hover{
  background-color: #fff !important;
  border:1px solid #20252b !important;
  color: #20252b !important;
}
.professors_carousel.owl-carousel .owl-nav .owl-prev{
  display: inline-block;
  width: 40px;
  height: 40px;
  border-radius: 100px;
  background: var(--titleColor) !important;
  color: white !important;
  font-size: 22px !important;
  top: 50%;
  left: -60px;
  transform: translateY(-50%);
  position: absolute;
}
.hidden-row {
  display: none;
}