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

:root {
  --primary-dark: #0f172a;
  --primary-blue: #1e293b;
  --accent-orange: #ff612e;
  --accent-orange-light: #fb923c;
  --light-gray: #e2e8f0;
  --dark-gray: #475569;
  --white: #ffffff;
  --gradient-bg: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  --premium-gold: #fcd34d;
  --text-light: #cbd5e1;
}

body {
  font-family: "Inter", "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--dark-gray);
  overflow-x: hidden;
  background: #fafafa;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  background: var(--gradient-bg);
  color: white;
  padding: 80px 0;
  position: relative;
  overflow: hidden;
}

.header-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-20px);
  }
}

.hero {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero-content h1 {
  font-size: 3.5rem;
  margin-bottom: 20px;
  font-weight: 700;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
  animation: slideInLeft 1s ease-out;
}

.hero-content .subtitle {
  font-size: 1.3rem;
  margin-bottom: 30px;
  opacity: 0.9;
  animation: slideInLeft 1s ease-out 0.2s both;
}

.hero-content .description {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 40px;
  max-width: 600px;
  animation: slideInLeft 1s ease-out 0.4s both;
  color: var(--text-light);
}

.profile-image {
  width: 250px;
  height: 250px;
  border-radius: 50%;
  border: 6px solid var(--accent-orange);
  box-shadow: 0 25px 50px rgba(249, 115, 22, 0.3);
  animation: slideInRight 1s ease-out 0.6s both;
  object-fit: cover;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-blue));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  color: var(--accent-orange);
  position: relative;
  overflow: hidden;
}

.profile-image::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(
    45deg,
    transparent,
    rgba(249, 115, 22, 0.1),
    transparent
  );
  animation: shimmer 3s infinite;
}

@keyframes shimmer {
  0% {
    transform: translateX(-100%) translateY(-100%) rotate(45deg);
  }
  100% {
    transform: translateX(100%) translateY(100%) rotate(45deg);
  }
}

@keyframes slideInLeft {
  from {
    transform: translateX(-100px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@keyframes slideInRight {
  from {
    transform: translateX(100px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.contact-links {
  display: flex;
  gap: 20px;
  margin-top: 30px;
}

.contact-links a {
  color: white;
  text-decoration: none;
  padding: 14px 28px;
  border: 2px solid var(--accent-orange);
  border-radius: 8px;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  background: rgba(249, 115, 22, 0.1);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
}

.contact-links a:hover {
  background: var(--accent-orange);
  transform: translateY(-2px);
  box-shadow: 0 15px 30px rgba(249, 115, 22, 0.4);
}

/* Navigation */
nav {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  padding: 20px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 20px rgba(15, 23, 42, 0.1);
}

.nav-links {
  display: flex;
  justify-content: center;
  gap: 40px;
  list-style: none;
}

.nav-links a {
  color: var(--primary-blue);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  transition: all 0.3s ease;
  position: relative;
  padding: 8px 0;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--accent-orange),
    var(--accent-orange-light)
  );
  transition: width 0.3s ease;
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-links a:hover {
  color: var(--accent-orange);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: none;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--primary-blue);
  cursor: pointer;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    background: white;
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    z-index: 100;
  }

  .profile-image {
    margin: 0 auto;
  }

  .nav-links.open {
    display: flex;
  }
  .nav-logo {
    display: block;
    font-weight: bold;
    font-size: 1.2rem;
    color: var(--primary-blue);
  }
  .menu-toggle {
    display: block;
  }

  .nav-logo {
    font-weight: bold;
    font-size: 1.2rem;
  }
}

/* Sections */
section {
  padding: 80px 0;
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 60px;
  color: var(--primary-dark);
  position: relative;
  font-weight: 700;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: -15px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--accent-orange),
    var(--accent-orange-light)
  );
  border-radius: 2px;
}

/* Education & Experience */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 100%;
  background: linear-gradient(
    to bottom,
    var(--light-gray),
    var(--accent-orange)
  );
  border-radius: 2px;
  transition: background 0.3s ease;
}

.timeline-progress {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 0%;
  background: linear-gradient(
    to bottom,
    var(--accent-orange),
    var(--accent-orange-light)
  );
  border-radius: 2px;
  transition: height 0.3s ease;
  z-index: 1;
}

.timeline-item {
  position: relative;
  margin-bottom: 60px;
  padding: 0 40px;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 20px;
  background: var(--accent-orange);
  border: 4px solid white;
  border-radius: 50%;
  top: 20px;
  z-index: 2;
  box-shadow: 0 0 0 4px rgba(249, 115, 22, 0.2);
}

.timeline-content {
  background: white;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.1);
  position: relative;
  width: 45%;
  transition: all 0.3s ease;
  border: 1px solid rgba(226, 232, 240, 0.5);
}

.timeline-content:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.15);
  border-color: var(--accent-orange);
}

.timeline-item:nth-child(even) .timeline-content {
  margin-left: auto;
}

.timeline-content h3 {
  color: var(--primary-dark);
  font-size: 1.4rem;
  margin-bottom: 10px;
  font-weight: 600;
}

.timeline-content .date {
  color: var(--accent-orange);
  font-weight: 600;
  margin-bottom: 15px;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.timeline-content .institution {
  font-weight: 600;
  margin-bottom: 15px;
  color: var(--primary-blue);
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
  margin-top: 60px;
}

.skill-category {
  background: white;
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease;
}

.skill-category:hover {
  transform: translateY(-5px);
}

.skill-category h3 {
  color: var(--primary-blue);
  margin-bottom: 20px;
  font-size: 1.3rem;
}

.skill-bar {
  margin-bottom: 20px;
}

.skill-name {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
  font-weight: 600;
}

.skill-progress {
  height: 8px;
  background: var(--light-gray);
  border-radius: 4px;
  overflow: hidden;
}

.skill-fill {
  height: 100%;
  background: linear-gradient(
    90deg,
    var(--accent-orange),
    var(--accent-orange-light)
  );
  border-radius: 4px;
  transition: width 2s ease;
  position: relative;
}

.skill-fill::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.3),
    transparent
  );
  animation: skill-shimmer 2s infinite;
}

@keyframes skill-shimmer {
  0% {
    transform: translateX(-100%);
  }
  100% {
    transform: translateX(100%);
  }
}

/* Publications */
.publications {
  background: #f8f9fa;
}

.publication-item {
  background: white;
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  margin-bottom: 30px;
  transition: transform 0.3s ease;
}

.publication-item:hover {
  transform: translateY(-5px);
}

.publication-item h3 {
  color: var(--primary-blue);
  margin-bottom: 15px;
}

.publication-item .journal {
  color: var(--accent-orange);
  font-weight: 600;
  margin-bottom: 10px;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Research Interests */
.interests-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.interest-card {
  background: white;
  padding: 30px;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.1);
  transition: all 0.3s ease;
  border-top: 4px solid var(--accent-orange);
  border: 1px solid rgba(226, 232, 240, 0.5);
}

.interest-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.15);
  border-color: var(--accent-orange);
}

.interest-card .icon {
  font-size: 3rem;
  margin-bottom: 20px;
  color: var(--accent-orange);
}

/* Footer */
footer {
  background: var(--primary-dark);
  color: var(--text-light);
  padding: 60px 0;
  text-align: center;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  margin-bottom: 20px;
  color: var(--accent-orange);
  font-weight: 600;
}

.footer-section a {
  color: var(--text-light);
  text-decoration: none;
  display: block;
  margin-bottom: 10px;
  transition: color 0.3s ease;
}

.footer-section a:hover {
  color: var(--accent-orange);
}

/* Responsive Design */
@media (max-width: 768px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 40px;
  }

  .hero-content h1 {
    font-size: 2.5rem;
  }

  .profile-image {
    width: 200px;
    height: 200px;
  }

  .nav-links {
    flex-direction: column;
    gap: 20px;
  }

  .timeline::before {
    left: 20px;
  }

  .timeline-item::before {
    left: 20px;
  }

  .timeline-content {
    width: calc(100% - 60px);
    margin-left: 60px;
  }

  .timeline-item:nth-child(even) .timeline-content {
    margin-left: 60px;
  }

  .contact-links {
    flex-direction: column;
    align-items: center;
  }
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.8s ease forwards;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.quantum-particle {
  position: absolute;
  width: 3px;
  height: 3px;
  background: var(--accent-orange);
  border-radius: 50%;
  bottom: -6px;
  animation: quantum-float 8s infinite linear;
  box-shadow: 0 0 6px var(--accent-orange);
}

@keyframes quantum-float {
  0% {
    transform: translateY(100vh) rotate(0deg);
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  90% {
    opacity: 1;
  }
  100% {
    transform: translateY(-100px) rotate(360deg);
    opacity: 0;
  }
}

/* Feather Icons Integration */
.feather {
  width: 20px;
  height: 20px;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

.feather-large {
  width: 48px;
  height: 48px;
}

#backToTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 999;
  background: var(--accent-orange);
  color: white;
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.4s ease, visibility 0.4s ease;
}

#backToTop.show {
  opacity: 1;
  visibility: visible;
}

#backToTop:hover {
  background: var(--accent-orange-light);
  transform: translateY(-4px);
}