/* Reset */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Poppins', sans-serif;
  background: linear-gradient(to right, #f8fbff, #eef6f9);
  scroll-behavior: smooth;
  overflow-x: hidden;
}

/* Layout Structure */
.layout {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 250px;
  background: #121212;
  color: white;
  position: fixed;
  height: 100vh;
  padding: 2rem 1rem;
  display: flex;
  flex-direction: column;
  z-index: 100;
  overflow-y: auto;
}

/* Hamburger Menu Toggle */
.menu-toggle {
  display: none;
  background: rgba(18, 18, 18, 0.9);
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.75rem;
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 101;
  border-radius: 8px;
  width: 48px;
  height: 48px;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  transition: all 0.3s ease;
}

.menu-toggle:hover {
  background: rgba(77, 208, 225, 0.9);
  color: white;
  transform: scale(1.05);
}

/* Mobile backdrop overlay */
.sidebar-backdrop {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  z-index: 99;
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.sidebar-backdrop.active {
  display: block;
  opacity: 1;
  pointer-events: auto;
}

.sidebar-header {
  text-align: center;
  margin-bottom: 2rem;
}

.profile-img {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 1rem;
  border: 3px solid #4dd0e1;
  display: block;
}

.name {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.title {
  font-size: 0.9rem;
  color: #aaa;
  margin-bottom: 1rem;
}

.nav-links {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: auto;
}

.nav-links a {
  color: #aaa;
  text-decoration: none;
  padding: 0.8rem 1rem;
  border-radius: 8px;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.nav-links a:hover, .nav-links a.active {
  background: rgba(77, 208, 225, 0.2);
  color: #4dd0e1;
}

.nav-links a i {
  width: 20px;
  text-align: center;
}

/* ✅ Extra spacing before email/contact */
.contact-info {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  margin-top: 2rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 0.8rem;
  color: #aaa;
  font-size: 0.75rem;
}

.contact-item i {
  width: 20px;
  text-align: center;
}

.main-content {
  flex: 1;
  margin-left: 280px;
  padding: 1rem;
}

/* Header */
header {
  background: linear-gradient(to right, #e0f7fa, #ffffff);
  padding: 1.5rem 2rem;
  border-radius: 12px;
  margin-bottom: 2rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.header-content h1 {
  font-size: 2.5rem;
  color: #004d40;
  margin-bottom: 0.5rem;
}

.header-content p {
  color: #555;
  line-height: 1.6;
}

/* Sections */
section {
  background: white;
  border-radius: 12px;
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  animation: fadeIn 1s ease-in-out;
}

.section-title {
  font-size: 1.8rem;
  color: #004d40;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid #e0e0e0;
}

/* About Section */
.about-content {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  align-items: center;
}

.about-img {
  flex: 1;
  min-width: 300px;
}

.about-img img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.about-text {
  flex: 2;
  min-width: 300px;
}

.about-text h2 {
  font-size: 1.8rem;
  color: #004d40;
  margin-bottom: 1rem;
}

/* Button Fix */
.btn {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  padding: 0.5rem 1rem;
  background: #4dd0e1;
  color: white;
  text-decoration: none;
  border-radius: 4px;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
}

.btn:hover {
  background: #26c6da;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(77, 208, 225, 0.3);
}

/* Social Icons */
.social-icons {
  margin-top: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.social-icons a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #aaa;
  font-size: 1.5rem;
  transition: all 0.3s ease;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
}

.social-icons a:hover {
  color: #4dd0e1;
  transform: translateY(-3px);
  background: rgba(77, 208, 225, 0.2);
}

.social-icons .btn {
  padding: 0.4rem 0.8rem;
  font-size: 0.85rem;
  width: auto;
  height: auto;
}

/* ✅ Gallery Responsive */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1rem;
}

.gallery-item { display: flex; 
  flex-direction: column; 
  border-radius: 8px; 
  overflow: hidden; 
  background: #fff; 
  box-shadow: 0 2px 8px rgba(0,0,0,0.03); 
} 

.gallery-item img { 
  width: 100%;
  height: auto; 
  aspect-ratio: 1 / 1;
  object-fit: cover; 
  display: block; 
  transition: transform 0.3s ease;
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.gallery-item figcaption {
  padding: 0.5rem 0.75rem;
  font-size: 0.9rem;
  color: #444;
  text-align: center;
  background: #fafafa;
  border-top: 1px solid rgba(0,0,0,0.03);
}

.gallery-item {
  cursor: pointer;
  transition: transform 0.35s ease, box-shadow 0.35s ease;
  position: relative;
}

.gallery-item::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(77, 208, 225, 0.15), rgba(0, 77, 64, 0.25));
  opacity: 0;
  transition: opacity 0.35s ease;
  pointer-events: none;
}

.gallery-item:hover,
.gallery-item:focus {
  transform: translateY(-6px);
  box-shadow: 0 18px 35px rgba(0, 77, 64, 0.12);
}

.gallery-item:hover::after,
.gallery-item:focus::after {
  opacity: 1;
}

.gallery-item:focus {
  outline: 3px solid rgba(77, 208, 225, 0.6);
  outline-offset: 4px;
}

body.lightbox-open {
  overflow: hidden;
}

.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(8, 19, 33, 0.75);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  z-index: 999;
  backdrop-filter: blur(4px);
}

.lightbox.active {
  display: flex;
}

.lightbox-content {
  position: relative;
  background: #0f172a;
  color: white;
  padding: 2.5rem 3.5rem;
  border-radius: 18px;
  max-width: min(900px, 90vw);
  width: 100%;
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.45);
  overflow: hidden;
}

.lightbox figure {
  margin: 0;
  text-align: center;
}

.lightbox-image {
  max-height: 65vh;
  width: 100%;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
}

.lightbox-caption {
  margin-top: 1.2rem;
  font-size: 1rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.86);
}

.lightbox-counter {
  margin-top: 1.5rem;
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(148, 163, 184, 0.9);
}

.lightbox-close {
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  background: rgba(148, 163, 184, 0.2);
  border: none;
  color: white;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  font-size: 1.2rem;
}

.lightbox-close:hover,
.lightbox-close:focus {
  background: rgba(77, 208, 225, 0.35);
  transform: scale(1.05);
}

.lightbox-nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(148, 163, 184, 0.2);
  border: none;
  color: white;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  font-size: 1.3rem;
}

.lightbox-nav:hover,
.lightbox-nav:focus {
  background: rgba(77, 208, 225, 0.35);
  transform: translateY(-50%) scale(1.08);
}

.lightbox-prev {
  left: 1.2rem;
}

.lightbox-next {
  right: 1.2rem;
}

.lightbox-nav i,
.lightbox-close i {
  pointer-events: none;
}

/* Research, Teaching, Talks Lists */
.research-list,
.teaching-list,
.talks-list,
.interests-list {
  list-style: none;
  padding: 0;
}

.research-list li,
.teaching-list li,
.talks-list li,
.interests-list li {
  padding: 1rem 0;
  border-bottom: 1px solid #f0f0f0;
  line-height: 1.6;
}

.research-list li:last-child,
.teaching-list li:last-child,
.talks-list li:last-child,
.interests-list li:last-child {
  border-bottom: none;
}

.research-list a,
.teaching-list a,
.talks-list a {
  color: #297eff;
  text-decoration: none;
  transition: color 0.3s ease;
}

.research-list a:hover,
.teaching-list a:hover,
.talks-list a:hover {
  color: #004d40;
  text-decoration: underline;
}

section h3 {
  font-size: 1.3rem;
  color: #004d40;
  margin-top: 1.5rem;
  margin-bottom: 1rem;
}

/* Gallery Link */
main > a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 1rem 1.5rem;
  background: linear-gradient(to right, #4dd0e1, #26c6da);
  color: white;
  text-decoration: none;
  border-radius: 8px;
  margin: 2rem 0;
  transition: all 0.3s ease;
  font-weight: 500;
  box-shadow: 0 4px 12px rgba(77, 208, 225, 0.3);
}

main > a:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(77, 208, 225, 0.4);
}

main > a i {
  font-size: 1.2rem;
}

/* Responsive Design */

/* Tablet */
@media (max-width: 992px) {
  .sidebar {
    width: 220px;
  }
  
  .main-content {
    margin-left: 230px;
    padding: 1rem;
  }

  .header-content h1 {
    font-size: 2rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

  section {
    padding: 1.5rem;
  }
}

/* Mobile - Sidebar with hamburger menu */
@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  .layout {
    flex-direction: column;
  }

  /* Backdrop should only be visible when active */
  .sidebar-backdrop { display: none; }
  .sidebar-backdrop.active { display: block; }

  .sidebar {
    width: 280px;
    max-width: 85%;
    height: auto;
    position: fixed;
    top: 0;
    left: 0;
    transform: translateX(-100%);
    transition: transform 0.35s ease, border-radius 0.35s ease, box-shadow 0.35s ease;
    padding: 1rem;
    padding-top: 4rem;
    max-height: 100vh;
    overflow-y: auto;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.3);
    border-top-right-radius: 20px;
    border-bottom-right-radius: 20px;
  }

  .sidebar.active {
    transform: translateX(0);
    animation: sidebarReveal 450ms ease both;
    box-shadow: 12px 0 40px rgba(0, 0, 0, 0.4);
  }

  .main-content {
    margin-left: 0;
    padding: 1rem;
    padding-top: calc(1rem + 56px + env(safe-area-inset-top, 0px));
    width: 100%;
    transition: filter 0.3s ease;
  }

  .main-content.dimmed {
    filter: brightness(0.6);
  }

  .nav-links {
    flex-direction: column;
    gap: 0.5rem;
    margin-top: 1rem;
  }

  .nav-links a {
    padding: 0.7rem 1rem;
    font-size: 0.9rem;
  }

  .profile-img {
    width: 100px;
    height: 100px;
  }

  .name {
    font-size: 1.2rem;
  }

  .title {
    font-size: 0.85rem;
  }

  .sidebar-header {
    margin-bottom: 1.5rem;
  }

  .contact-item {
    font-size: 0.8rem;
    justify-content: center;
    flex-wrap: wrap;
    text-align: center;
  }

  .social-icons {
    margin-top: 1rem;
    gap: 0.8rem;
  }

  .social-icons a {
    width: 36px;
    height: 36px;
    font-size: 1.2rem;
  }

  /* Header */
  header {
    padding: 1rem 1.5rem;
    margin-bottom: 1.5rem;
  }

  .header-content h1 {
    font-size: 1.8rem;
  }

  /* Sections */
  section {
    padding: 1.5rem;
    margin-bottom: 1.5rem;
  }

  .section-title {
    font-size: 1.5rem;
    margin-bottom: 1rem;
  }

  section h3 {
    font-size: 1.1rem;
    margin-top: 1.2rem;
    margin-bottom: 0.8rem;
  }

  /* About Section */
  .about-content {
    flex-direction: column;
    gap: 1.5rem;
  }

  .about-text {
    min-width: 100%;
  }

  .about-text h2 {
    font-size: 1.5rem;
  }

  .about-text p {
    font-size: 0.95rem;
    line-height: 1.7;
  }

  /* Lists */
  .research-list li,
  .teaching-list li,
  .talks-list li,
  .interests-list li {
    padding: 0.8rem 0;
    font-size: 0.9rem;
  }

  /* Gallery */
  .gallery {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .gallery-item figcaption {
    font-size: 0.85rem;
    padding: 0.4rem 0.6rem;
  }

  /* Gallery Link */
  main > a {
    padding: 0.8rem 1.2rem;
    font-size: 0.9rem;
    width: 100%;
    justify-content: center;
    margin: 1.5rem 0;
  }
}

/* Small Phones */
@media (max-width: 480px) {
  .menu-toggle {
    top: 0.75rem;
    left: 0.75rem;
    width: 44px;
    height: 44px;
    font-size: 1.3rem;
  }

  .sidebar {
    padding: 1rem;
    padding-top: 3.5rem;
  }

  .profile-img {
    width: 80px;
    height: 80px;
  }

  .name {
    font-size: 1.1rem;
  }

  .title {
    font-size: 0.8rem;
  }

  .nav-links a {
    padding: 0.6rem 0.8rem;
    font-size: 0.85rem;
  }

  .nav-links a i {
    width: 18px;
    font-size: 0.9rem;
  }

  .main-content {
    padding: 0.8rem;
    padding-top: calc(0.8rem + 56px + env(safe-area-inset-top, 0px));
  }

  header {
    padding: 1rem;
    border-radius: 8px;
  }

  .header-content h1 {
    font-size: 1.5rem;
  }

  section {
    padding: 1rem;
    border-radius: 8px;
  }

  .section-title {
    font-size: 1.3rem;
  }

  section h3 {
    font-size: 1rem;
  }

  .about-text h2 {
    font-size: 1.3rem;
  }

  .about-text p {
    font-size: 0.9rem;
  }

  .research-list li,
  .teaching-list li,
  .talks-list li,
  .interests-list li {
    padding: 0.7rem 0;
    font-size: 0.85rem;
  }

  .gallery {
    grid-template-columns: 1fr;
    gap: 1.1rem;
  }

  .contact-item {
    font-size: 0.75rem;
  }

  .contact-item span {
    word-break: break-word;
  }

  .social-icons {
    gap: 0.6rem;
  }

  .social-icons a {
    width: 32px;
    height: 32px;
    font-size: 1rem;
  }

  .btn {
    padding: 0.4rem 0.8rem;
    font-size: 0.8rem;
  }

  main > a {
    padding: 0.7rem 1rem;
    font-size: 0.85rem;
  }
}

/* Extra Small Phones */
@media (max-width: 360px) {
  .header-content h1 {
    font-size: 1.3rem;
  }

  .section-title {
    font-size: 1.2rem;
  }

  .about-text p,
  .research-list li,
  .teaching-list li,
  .talks-list li,
  .interests-list li {
    font-size: 0.8rem;
  }
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Animated rounded-corner reveal for sidebar */
@keyframes sidebarReveal {
  0% {
    transform: translateX(-100%);
    border-top-right-radius: 40px;
    border-bottom-right-radius: 40px;
  }
  60% {
    transform: translateX(-6%);
  }
  100% {
    transform: translateX(0);
    border-top-right-radius: 20px;
    border-bottom-right-radius: 20px;
  }
}

@media (max-width: 992px) {
  .lightbox-content {
    padding: 2rem 2.5rem;
  }

  .lightbox-image {
    max-height: 60vh;
  }

  .lightbox-prev {
    left: 0.75rem;
  }

  .lightbox-next {
    right: 0.75rem;
  }
}

@media (max-width: 768px) {
  .lightbox {
    padding: 1.5rem;
  }

  .lightbox-content {
    padding: 1.75rem;
    border-radius: 16px;
  }

  .lightbox-nav {
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 576px) {
  .lightbox-content {
    padding: 1.5rem;
  }

  .lightbox-image {
    max-height: 55vh;
  }

  .lightbox-caption {
    font-size: 0.95rem;
  }

  .lightbox-counter {
    margin-top: 1rem;
    font-size: 0.75rem;
  }

  .lightbox-close {
    top: 0.8rem;
    right: 0.8rem;
  }

  .lightbox-nav {
    width: 40px;
    height: 40px;
    font-size: 1.1rem;
  }

  .lightbox-prev {
    left: 0.5rem;
  }

  .lightbox-next {
    right: 0.5rem;
  }
}