* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Poppins', sans-serif;
  color: #fff;
  min-height: 100vh;
  background: radial-gradient(circle at 20% 20%, #071a3d 0%, #02040d 35%, #000 100%);
  overflow-x: hidden;
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(circle at 30% 20%, rgba(79, 195, 247, 0.14) 0%, transparent 35%),
    radial-gradient(circle at 70% 40%, rgba(255, 215, 120, 0.1) 0%, transparent 35%),
    radial-gradient(circle at 50% 80%, rgba(158, 240, 255, 0.08) 0%, transparent 45%);
  animation: pulseBg 18s ease-in-out infinite;
  z-index: -2;
}

@keyframes pulseBg {
  0%,
  100% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.03);
    opacity: 0.92;
  }
}

.satellite-grid {
  position: fixed;
  inset: 0;
  background-image: radial-gradient(2px 2px at 10% 20%, rgba(255, 255, 255, 0.45), transparent 40%),
    radial-gradient(2px 2px at 40% 70%, rgba(255, 255, 255, 0.3), transparent 40%),
    radial-gradient(2px 2px at 70% 35%, rgba(255, 255, 255, 0.5), transparent 40%);
  z-index: -1;
  pointer-events: none;
  animation: drift 60s linear infinite;
}

@keyframes drift {
  from {
    transform: translate(0, 0);
  }
  to {
    transform: translate(-120px, 90px);
  }
}

nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 16px 32px;
  background: rgba(5, 25, 47, 0.88);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(79, 195, 247, 0.2);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

nav h1 {
  display: none;
}

nav ul {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

nav a {
  color: #c5deff;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 10px 18px;
  border-radius: 8px;
  position: relative;
  transition: all 0.3s ease;
  letter-spacing: 0.4px;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: 8px;
  left: 18px;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #4fbeff, #00e5ff);
  transition: width 0.3s ease;
  border-radius: 1px;
}

nav a:hover {
  color: #ffffff;
  background: rgba(79, 195, 247, 0.12);
}

nav a:hover::after {
  width: calc(100% - 36px);
}

nav a:focus {
  color: #ffffff;
  background: rgba(79, 195, 247, 0.15);
}

nav a:focus::after {
  width: calc(100% - 36px);
}

.hero {
  text-align: center;
  padding: 80px 20px 50px;
  margin-top: 0;
  position: relative;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0, 188, 212, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
}

.hero h2 {
  margin: 0 0 0 0;
  font-size: clamp(2rem, 5vw, 2.8rem);
  line-height: 1.3;
  background: linear-gradient(135deg, #4fbeff 0%, #00bcd4 40%, #00e5ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-align: center;
  font-weight: 700;
  letter-spacing: 0.5px;
  position: relative;
  z-index: 1;
  animation: heroFadeIn 1s ease-out;
}

.hero-subtitle {
  display: none;
}

@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero p {
  margin: 20px auto;
  max-width: 900px;
  color: #dbeafe;
  font-size: 1.15rem;
  line-height: 1.6;
}

.button {
  display: inline-block;
  margin-top: 22px;
  padding: 14px 28px;
  background: #00bcd4;
  color: #031c35;
  text-decoration: none;
  border-radius: 30px;
  font-weight: 700;
  box-shadow: 0 8px 20px rgba(0, 188, 212, 0.35);
  transition: all 0.25s ease;
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 26px rgba(0, 188, 212, 0.45);
}

/* Scroll-triggered animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

section {
  padding: 90px 8vw;
  max-width: 1300px;
  margin: 0 auto;
  opacity: 0;
  animation: fadeInUp 0.8s ease-out forwards;
}

section.visible {
  animation: fadeInUp 0.8s ease-out forwards;
}

section:not(.visible) {
  opacity: 0;
}

section h2 {
  margin-bottom: 42px;
  margin-top: 0;
  color: #f0f8ff;
  font-size: 2rem;
  letter-spacing: 0.4px;
  text-align: center;
}

section p,
section li {
  color: #dde8fc;
  line-height: 1.7;
}

#intro p {
  max-width: 1000px;
  margin: 0 auto 24px auto;
  text-align: justify;
  line-height: 1.85;
  font-size: 1rem;
}

#intro p:last-child {
  margin-bottom: 0;
}

#project p {
  max-width: 1000px;
  margin: 0 auto 24px auto;
  text-align: justify;
  line-height: 1.85;
  font-size: 1rem;
}

#project p:last-child {
  margin-bottom: 0;
}

.team-container {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  max-width: 1100px;
  margin: 0 auto;
}

.member {
  background: rgba(5, 25, 47, 0.9);
  padding: 32px;
  border-radius: 12px;
  border: 1.5px solid rgba(79, 195, 247, 0.3);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
  text-align: center;
}

.member:hover {
  transform: translateY(-8px);
  border-color: rgba(79, 195, 247, 0.6);
  box-shadow: 0 16px 40px rgba(0, 188, 212, 0.25);
  background: rgba(5, 25, 47, 0.95);
}

.member h3 {
  margin: 0 0 6px 0;
  color: #e5f3ff;
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.3px;
}

.role {
  color: #4fbeff;
  font-weight: 600;
  font-size: 0.9rem;
  margin: 0 0 12px 0;
  letter-spacing: 0.2px;
  text-transform: uppercase;
}

.member .description {
  margin: 0 0 20px 0;
  color: #b8d8ff;
  font-size: 0.88rem;
  line-height: 1.5;
  flex-grow: 1;
}

.contact {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: auto;
  padding-top: 16px;
}

.contact a {
  font-size: 1.8rem;
  text-decoration: none;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(79, 195, 247, 0.1);
  border: 1.5px solid rgba(79, 195, 247, 0.3);
}

.contact a:hover {
  background: rgba(79, 195, 247, 0.25);
  border-color: rgba(79, 195, 247, 0.8);
  transform: scale(1.1);
}

.results-showcase {
  margin-top: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  max-width: 1100px;
  margin-left: auto;
  margin-right: auto;
}

.result-image-container {
  background: rgba(8, 22, 50, 0.75);
  border: 1px solid rgba(143, 197, 255, 0.25);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.result-image-container:hover {
  transform: translateY(-8px);
  border-color: rgba(0, 188, 212, 0.7);
  box-shadow: 0 20px 40px rgba(0, 188, 212, 0.2);
}

.result-image-container img {
  width: 100%;
  display: block;
  object-fit: cover;
}

.resources-intro {
  max-width: 1100px;
  margin: -20px auto 50px auto;
  text-align: center;
  color: #b8d8ff;
  font-size: 0.95rem;
  line-height: 1.7;
}

.resources-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  max-width: 600px;
  margin: 0 auto 60px auto;
}

.resource-card {
  background: rgba(5, 25, 47, 0.9);
  border: 1.5px solid rgba(79, 195, 247, 0.3);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.resource-card:hover {
  transform: translateY(-8px);
  border-color: rgba(79, 195, 247, 0.6);
  box-shadow: 0 16px 40px rgba(0, 188, 212, 0.25);
  background: rgba(5, 25, 47, 0.95);
}

.resource-icon {
  font-size: 3.5rem;
  margin-bottom: 16px;
  display: inline-block;
  transition: transform 0.3s ease;
}

.resource-card:hover .resource-icon {
  transform: scale(1.15);
}

.resource-card h3 {
  margin: 0 0 12px 0;
  color: #e5f3ff;
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.resource-card p {
  margin: 0 0 24px 0;
  color: #b8d8ff;
  font-size: 0.9rem;
  line-height: 1.6;
  flex-grow: 1;
}

.resource-btn {
  display: inline-block;
  margin-top: auto;
  padding: 12px 32px;
  background: linear-gradient(135deg, #4fbeff 0%, #00bcd4 100%);
  color: #031c35;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 700;
  font-size: 0.95rem;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(79, 195, 247, 0.25);
}

.resource-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79, 195, 247, 0.4);
  background: linear-gradient(135deg, #5fc5ff 0%, #00d1db 100%);
}

.datasets-section {
  max-width: 1300px;
  margin: 0 auto;
  padding-top: 40px;
  border-top: 1px solid rgba(79, 195, 247, 0.2);
}

.datasets-section h3 {
  text-align: center;
  color: #e5f3ff;
  font-size: 1.8rem;
  margin-bottom: 12px;
  font-weight: 700;
}

.datasets-intro {
  text-align: center;
  color: #b8d8ff;
  font-size: 0.9rem;
  margin-bottom: 36px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

.datasets-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  max-width: 1050px;
  margin: 0 auto;
  justify-content: center;
}

@media (max-width: 1024px) {
  .datasets-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
}

@media (max-width: 640px) {
  .datasets-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

.dataset-card {
  background: rgba(5, 25, 47, 0.8);
  border: 1.5px solid rgba(79, 195, 247, 0.3);
  border-radius: 12px;
  padding: 24px;
  text-align: center;
  transition: all 0.3s ease;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 200px;
}

.dataset-card:hover {
  transform: translateY(-6px);
  border-color: rgba(79, 195, 247, 0.6);
  box-shadow: 0 10px 28px rgba(0, 188, 212, 0.2);
  background: rgba(5, 25, 47, 0.9);
}

.dataset-card h4 {
  margin: 0 0 12px 0;
  color: #4fbeff;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.dataset-card p {
  margin: 0;
  color: #a8d8ff;
  font-size: 0.9rem;
  line-height: 1.6;
}

.papers-intro {
  text-align: center;
  color: #b8d8ff;
  font-size: 0.9rem;
  margin-bottom: 36px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

.papers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 28px;
  max-width: 1300px;
  margin: 0 auto;
}

.paper-card {
  background: rgba(5, 25, 47, 0.9);
  border: 1.5px solid rgba(79, 195, 247, 0.3);
  border-radius: 12px;
  padding: 28px;
  text-align: center;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.paper-card:hover {
  transform: translateY(-6px);
  border-color: rgba(79, 195, 247, 0.6);
  box-shadow: 0 16px 40px rgba(0, 188, 212, 0.25);
  background: rgba(5, 25, 47, 0.95);
}

.paper-icon {
  font-size: 3rem;
  margin-bottom: 12px;
  display: inline-block;
  transition: transform 0.3s ease;
}

.paper-card:hover .paper-icon {
  transform: scale(1.1);
}

.paper-card h3 {
  margin: 0 0 6px 0;
  color: #e5f3ff;
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.paper-semester {
  margin: 0 0 10px 0;
  color: #4fbeff;
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.paper-description {
  display: none;
}

.paper-btn {
  display: inline-block;
  margin-top: auto;
  padding: 10px 28px;
  background: linear-gradient(135deg, #4fbeff 0%, #00bcd4 100%);
  color: #031c35;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 700;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(79, 195, 247, 0.25);
}

.paper-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79, 195, 247, 0.4);
  background: linear-gradient(135deg, #5fc5ff 0%, #00d1db 100%);
}

.paper-btn:disabled,
.paper-btn[disabled] {
  opacity: 0.6;
  cursor: not-allowed;
}

footer {
  text-align: center;
  padding: 24px 14px;
  background: rgba(2, 7, 21, 0.85);
  color: #c7d8f3;
  border-top: 1px solid rgba(179, 215, 255, 0.15);
  margin-top: 30px;
}

footer p {
  margin: 0;
  font-size: 0.85rem;
  line-height: 1.5;
  color: #b8d8ff;
  font-weight: 500;
}

/* Image Modal Lightbox */
.modal {
  display: none;
  position: fixed;
  z-index: 9999;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.95);
  animation: fadeIn 0.3s ease-out;
}

.modal.show {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-image {
  max-width: 90%;
  max-height: 90vh;
  border-radius: 12px;
  box-shadow: 0 0 60px rgba(79, 195, 247, 0.4);
  animation: zoomIn 0.4s ease-out;
  object-fit: contain;
}

.close-btn {
  position: absolute;
  top: 30px;
  right: 40px;
  color: #e5f3ff;
  font-size: 40px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  text-shadow: 0 0 20px rgba(79, 195, 247, 0.3);
}

.close-btn:hover {
  color: #4fbeff;
  text-shadow: 0 0 30px rgba(79, 195, 247, 0.6);
  transform: scale(1.2);
}

.clickable-image {
  cursor: pointer;
  transition: all 0.3s ease;
}

.clickable-image:hover {
  filter: brightness(1.1) drop-shadow(0 0 15px rgba(79, 195, 247, 0.4));
}

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

@keyframes zoomIn {
  from {
    opacity: 0;
    transform: scale(0.7);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@media (max-width: 900px) {
  section {
    padding: 46px 5vw;
  }
  nav {
    padding: 12px 18px;
  }
  nav h1 {
    font-size: 1rem;
  }
}