@font-face {
  font-family: 'Poppins';
  src: url('../fonts/Poppins-Regular.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'Poppins';
  src: url('../fonts/Poppins-Medium.ttf') format('truetype');
  font-weight: 500;
  font-style: normal;
}

@font-face {
  font-family: 'Poppins';
  src: url('../fonts/Poppins-SemiBold.ttf') format('truetype');
  font-weight: 600;
  font-style: normal;
}

body {
  font-family: 'Poppins', sans-serif;
}
.text-primary {
  color: #000 !important; /* istediğin renk kodu */
}
/* HEADER */
.navbar {
  transition: all 0.3s ease;
}

.navbar .nav-link {
  font-size: 1rem;
  font-weight: 500;
  color: #333 !important;
  margin: 0 12px;
  position: relative;
  transition: color 0.3s ease;
}

.navbar .nav-link::after {
  content: "";
  position: absolute;
  width: 0%;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: #007bff;
  transition: width 0.3s ease;
}

.navbar .nav-link:hover {
  color: #007bff !important;
}

.navbar .nav-link:hover::after,
.navbar .nav-link.active::after {
  width: 100%;
}


/* FOOTER */
footer .col-md-4:nth-child(2),
footer .col-md-4:nth-child(3) {
  text-align: center;
}
footer .col-md-4:nth-child(2) ul {
  display: inline-block;
  text-align: center;
}
footer .col-md-4:nth-child(3) p {
  justify-content: center !important;
}
/* WhatsApp Button - Mobil uyumlu */
.whatsapp-float {
    position: fixed;
    width: 60px;
    height: 60px;
    bottom: 25px;
    right: 15px; /* ekran dışına taşmayı önler */
    background-color: #25d366;
    border-radius: 50%;
    text-align: center;
    font-size: 30px;
    box-shadow: 3px 4px 3px #999;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

/* WhatsApp ikon boyutu */
.whatsapp-float img {
    width: 35px;
    height: 35px;
}

/* Hover efekti */
.whatsapp-float:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 15px rgba(0,0,0,0.3);
}

/* Tablet ve Mobil Uyumluluk */
@media (max-width: 991px) {
    .whatsapp-float {
        width: 50px;
        height: 50px;
        bottom: 20px;
        right: 7%; /* fazla kaymayı engeller */
    }
    .whatsapp-float img {
        width: 28px;
        height: 28px;
    }
}

@media (max-width: 600px) {
    .whatsapp-float {
        width: 45px;
        height: 45px;
        bottom: 15px;
        right: 7%; /* daha küçük ekranlar için */
    }
    .whatsapp-float img {
        width: 25px;
        height: 25px;
    }
}


/* INDEX START */

.hero-section img {
  max-height: 800px;
  object-fit: contain;
}

.card:hover {
    transform: translateY(-5px) !important;
    box-shadow: 0 8px 20px rgba(0,0,0,0.15) !important;
    transition: all 0.3s ease !important;
}

.card {
    transition: all 0.3s ease !important;
}


/* Accordion Section */
.accordion-group {
  display: flex;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  margin: 0;
  padding: 0;
}

.accordion-group li {
  list-style: none;
  flex: 1;
  position: relative;
  background-size: cover;
  background-position: center;
  transition: all 0.5s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: #fff;
  text-align: center;
}

.accordion-group li .accordion-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  transition: all 0.5s ease;
  z-index: 1;
}

.accordion-group li section {
  position: relative;
  z-index: 2;
  width: 100%;
}

.accordion-group li h3 {
  font-size: 2rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  position: relative;
  z-index: 2;
}

.accordion-group li p {
  font-size: 1rem;
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: opacity 0.5s ease, max-height 0.5s ease;
  position: relative;
  z-index: 2;
}

.accordion-group li.out p {
  opacity: 1;
  max-height: 200px;
}

.accordion-group li.out {
  flex: 4;
}

.accordion-group li.out .accordion-overlay {
  background: rgba(0, 0, 0, 0.4);
}

@media (max-width: 768px) {
  .accordion-group {
    flex-direction: column;
    height: 600px;
  }
  .accordion-group li.out {
    flex: 3;
  }
}

/* References Section */
.blurer-right{
    right: 0 !important;
    transform: rotate(180deg);
    position: absolute;
    background: linear-gradient(90deg, #f8f9fa 25.23%, hsla(0, 0%, 100%, 0));
    z-index: 1;
    height: 100%;
    width: 222px;
    display: flex !important;
}
.blurer-left{
    left: 0 !important;
    transform: rotate(180deg);
    position: absolute;
    background: linear-gradient(270deg, #f8f9fa 25.23%, hsla(0, 0%, 100%, 0));
    z-index: 1;
    height: 100%;
    width: 222px;
}
.logos-slider {
  overflow: hidden;
  position: relative;
  width: 100%;
  display: grid;
}

.logos-track {
  display: flex;
  width: calc(250px * 12);
  animation: scroll 15s linear infinite;
}

.logo-item {
  flex: 0 0 250px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px;
}

.logo-item img {
  width: 140px;
  height: auto;
  opacity: 0.8;
  transition: opacity 0.3s ease;
  filter: grayscale(100%);
}

.logo-item img:hover {
  opacity: 1;
  filter: grayscale(0%);
}

@keyframes scroll {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(-50%);
  }
}

@media (max-width: 991px) {
  .logos-track {
    width: calc(180px * 12);
    animation-duration: 22s; /* Daha yavaş kaydırma */
  }

  .logo-item {
    flex: 0 0 180px;
    padding: 8px;
  }

  .logo-item img {
    width: 100px;
    opacity: 0.85;
  }

  .blurer-right,
  .blurer-left {
    width: 100px;
  }
}

@media (max-width: 600px) {
  .logos-track {
    width: calc(140px * 12);
    animation-duration: 28s;
  }

  .logo-item {
    flex: 0 0 140px;
    padding: 6px;
  }

  .logo-item img {
    width: 80px;
  }

  .blurer-right,
  .blurer-left {
    width: 100px;
  }
}

/*INDEX END*/

/* ABOUT PAGE START */

.about-hero {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  text-align: center;
}

.timeline {
  position: relative;
  margin: 2rem 0;
  padding-left: 2rem;
  border-left: 2px solid #00b4d8;
}
.timeline-item {
  margin-bottom: 1.5rem;
  position: relative;
}
.timeline-item .year {
  font-weight: 600;
  color: #0077b6;
  margin-bottom: 0.3rem;
}
.timeline-item::before {
  content: "";
  position: absolute;
  left: -10px;
  top: 5px;
  width: 15px;
  height: 15px;
  background: #00b4d8;
  border-radius: 50%;
}

.stats h2 {
  font-size: 2.4rem;
}

@media (max-width: 600px) {
  .about-hero {
    min-height: 40vh;
    padding: 0 10px; /* sağ ve sol taşmayı engelle */
  }

  .timeline {
    padding-left: 0.6rem; /* sol boşluğu daha da azalt */
  }

  .timeline-item .year {
    font-size: 0.85rem;
  }

  .timeline-item::before {
    width: 10px;
    height: 10px;
    left: -5px;
    top: 3px;
  }

  .stats h2 {
    font-size: 1.6rem;
  }
}
/* ABOUT PAGE END */

/* SERVICES PAGE START */

.page {
  width: 100vw;
  height: 100vh;
  min-height: 700px;
  overflow: hidden;
  font-family: 'Open Sans', sans-serif;
}

/* Tabs */
.tabs-controls {
  position: relative;
  z-index: 10;
  display: flex;
  justify-content: center;
  align-items: stretch;
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  box-sizing: border-box;
  padding: 50px 0 50px;
  list-style-type: none;
}

.tabs-controls__link {
  position: relative;
  display: block;
  padding: 16px 32px;
  font-size: 20px;
  font-weight: 700;
  color: #423E37;
  text-transform: uppercase;
  text-decoration: none;
  transition: color 0.3s;
}

.tabs-controls__link::after {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: block;
  width: 0;
  height: 4px;
  background-color: #423E37;
  border-radius: 2px;
  margin: auto;
  content: '';
  transition: width 0.4s;
}

.tabs-controls__link--active::after {
  width: 100%;
}

/* Cards (renamed) */
.papers-container {
  position: relative;
  z-index: 1;
  width: 500px;
  height: calc(65vh - 205px);
  margin: 0 auto;
}

.paper-card {
  position: absolute;
  width: 500px;
  height: 300px;
  background-color: #fff;
  border: 1px solid #423E37;
  box-shadow: 9px 11px 3px 0px rgba(0, 0, 0, 0.2);
  box-sizing: border-box;
  padding: 40px;
  transition: transform 1s ease, opacity 0.6s ease, background-color 0.4s ease;
}

.paper-card-black {
  position: absolute;
  width: 500px;
  height: 300px;
  background-color: #000 !important;
  border: 1px solid #423E37;
  box-shadow: 9px 11px 3px 0px rgba(0, 0, 0, 0.2);
  box-sizing: border-box;
  padding: 40px;
  transition: transform 1s ease, opacity 0.6s ease, background-color 0.4s ease;
  color: #fff;
}


.paper-card:nth-of-type(1) { z-index: 5; transform: translate(0px, 0px); }
.paper-card:nth-of-type(2) { z-index: 4; transform: translate(10px, 10px); }
.paper-card:nth-of-type(3) { z-index: 3; transform: translate(20px, 20px); }
.paper-card:nth-of-type(4) { z-index: 2; transform: translate(30px, 30px); }
.paper-card:nth-of-type(5) { z-index: 1; transform: translate(40px, 40px); }
.paper-card:nth-of-type(6) { z-index: 0; transform: translate(50px, 50px); }

.paper-card.hidden {
  opacity: 0;
  background-color: #fff;
  color: #fff;
}

@media (max-width: 991px) {
  .papers-container {
    width: 90vw;
    height: auto;
    min-height: 400px;
  }

  .paper-card {
    width: 90vw;
    height: auto;
    min-height: 260px;
    padding: 25px;
  }

  .tabs-controls {
    padding: 30px 10px 70px;
  }

  .tabs-controls__link {
    font-size: 16px;
    padding: 12px 20px;
  }
  .paper-card:nth-of-type(1) { z-index: 5; transform: translate(0px, 0px); }
  .paper-card:nth-of-type(2) { z-index: 4; transform: translate(0px, 10px); }
  .paper-card:nth-of-type(3) { z-index: 3; transform: translate(0px, 20px); }
  .paper-card:nth-of-type(4) { z-index: 2; transform: translate(0px, 30px); }
  .paper-card:nth-of-type(5) { z-index: 1; transform: translate(0px, 40px); }
  .paper-card:nth-of-type(6) { z-index: 0; transform: translate(0px, 50px); }
}

@media (max-width: 600px) {
  .tabs-controls {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px; 
    padding: 20px 10px 60px;
    justify-items: center;
  }

  .tabs-controls__item {
    width: 100%; /* sütun genişliğini doldur */
  }

  .tabs-controls__link {
    display: block;
    text-align: center;
    font-size: 14px;
    padding: 10px 0;
  }
}

/*PROJECTS PAGE*/

.projects-hero {
  min-height: 45vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.filter-btn {
  border: none;
  background: #f1f1f1;
  padding: 10px 20px;
  margin: 5px;
  border-radius: 25px;
  cursor: pointer;
  transition: 0.3s ease;
  font-weight: 500;
}
.filter-btn:hover,
.filter-btn.active {
  background: #0077b6;
  color: #fff;
}

.project-card {
  position: relative;
  overflow: hidden;
  border-radius: 15px;
  cursor: pointer;
  transition: transform 0.3s ease;
}
.project-card img {
  width: 100%;
  height: 250px;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.project-card:hover img {
  transform: scale(1.1);
}
.project-card .overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  opacity: 0;
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: opacity 0.4s ease;
}
.project-card:hover .overlay {
  opacity: 1;
}
.project-card .overlay h5 {
  font-weight: 600;
  margin-bottom: 5px;
}
.project-card .overlay p {
  font-size: 0.9rem;
  opacity: 0.85;
}

.project-item.selected .project-card {
  outline: 3px solid #0077b6;
  transform: scale(1.05);
  transition: transform 0.3s ease, outline 0.3s ease;
}

@media (max-width: 991px) {
  .center-text {
      text-align: center !important;
  }
}

@media (max-width: 600px) {
  .center-text {
      text-align: center !important;
  }
}


/*
.book {
  position: relative;
  border-radius: 15px;
  height: 250px;
  background-color: whitesmoke;
  -webkit-box-shadow: 1px 1px 12px #000;
  box-shadow: 1px 1px 12px #000;
  -webkit-transform: preserve-3d;
  -ms-transform: preserve-3d;
  transform: preserve-3d;
  -webkit-perspective: 2000px;
  perspective: 2000px;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  color: #000;
}

.cover {
  top: 0;
  position: absolute;
  background-color: lightgray;
  width: 100%;
  height: 100%;
  border-radius: 10px;
  cursor: pointer;
  -webkit-transition: all 0.5s;
  transition: all 0.5s;
  -webkit-transform-origin: 0;
  -ms-transform-origin: 0;
  transform-origin: 0;
  -webkit-box-shadow: 1px 1px 12px #000;
  box-shadow: 1px 1px 12px #000;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  background: rgba(0,0,0,1)
}
.cover img {
  width: 100%;
  height: 100%;
  border-radius: 15px;
  object-fit: cover;
  transition: transform 0.5s ease;
  opacity: 0.5;
  position: absolute;
} 

.cover p{
  color: #fff;
  z-index:999;
} 

.book:hover .cover {
  -webkit-transition: all 0.5s;
  transition: all 0.5s;
  -webkit-transform: rotatey(-90deg);
  -ms-transform: rotatey(-90deg);
  transform: rotatey(-90deg);
}
*/ 

/* CONTACT PAGE */

.contact-hero {
  min-height: 45vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.contact {
  position: relative;
  margin: 2rem 0;
  padding-left: 2rem;
  border-left: 2px solid #00b4d8;
}
.contact-item {
  margin-bottom: 1.5rem;
  position: relative;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -10px;
  top: 5px;
  width: 15px;
  height: 15px;
  background: #00b4d8;
  border-radius: 50%;
}