/* ============================================
   RESET & BASE
   ============================================ */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #050505;
  --surface: #0a0a0a;
  --border: #1a1a1a;
  --text: #ffffff;
  --text-dim: #666;
  --accent: #3b82f6;
  --accent-glow: rgba(59, 130, 246, 0.4);
}

/* Light Mode */
[data-theme="light"] {
  --bg: #ffffff;
  --surface: #f5f5f5;
  --border: #e5e5e5;
  --text: #171717;
  --text-dim: #737373;
  --accent: #2563eb;
  --accent-glow: rgba(37, 99, 235, 0.3);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  overflow-x: hidden;
}

::selection {
  background: var(--accent);
  color: white;
}

/* ============================================
   BACKGROUND
   ============================================ */
#particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.8;
  display: block;
  background: transparent;
  /* iOS Safari fix */
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
}

/* ============================================
   LAYOUT
   ============================================ */
.main {
  position: relative;
  z-index: 1;
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0 10vw;
  position: relative;
}

.hero-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.3em;
  color: var(--text-dim);
  margin-bottom: 2rem;
  opacity: 0;
  animation: fadeIn 1s ease forwards;
  animation-delay: 0.5s;
}

.hero-name {
  font-size: clamp(3rem, 12vw, 10rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 0.9;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
}

.hero-name .name-line:first-child {
  font-size: 0.85em;
  word-spacing: 10px;
}

.name-line {
  display: block;
  background: linear-gradient(135deg, #fff 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  cursor: pointer;
  position: relative;
  min-height: 1em;
}

/* Prevent layout shift by using invisible text for sizing */
.name-line::before {
  content: attr(data-text);
  visibility: hidden;
  display: block;
  height: 0;
  overflow: hidden;
}

.hero-name .scramble-char {
  color: var(--accent);
  -webkit-text-fill-color: var(--accent);
}

.hero-tagline {
  font-size: clamp(1rem, 2vw, 1.5rem);
  color: var(--text-dim);
  max-width: 500px;
  margin-bottom: 3rem;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards;
  animation-delay: 1s;
}

.hero-cta {
  display: flex;
  gap: 1.5rem;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards;
  animation-delay: 1.2s;
}

/* Magnetic Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 2.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 50px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn svg {
  width: 18px;
  height: 18px;
  transition: transform 0.3s ease;
}

.btn-primary {
  background: var(--accent);
  color: white;
  border: none;
  position: relative;
  overflow: hidden;
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  transition: width 0.6s ease, height 0.6s ease;
}

.btn-primary:hover::before {
  width: 300px;
  height: 300px;
}

.btn-primary:hover {
  box-shadow: 0 0 40px var(--accent-glow);
}

.btn-primary:hover svg {
  transform: translateX(4px);
}

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--text);
  background: rgba(255, 255, 255, 0.05);
}

/* Hero scroll hint */
.hero-scroll {
  position: absolute;
  bottom: 3rem;
  left: 10vw;
  display: flex;
  align-items: center;
  gap: 1rem;
  opacity: 0;
  animation: fadeIn 1s ease forwards;
  animation-delay: 2s;
}

.hero-scroll span {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-dim);
}

.scroll-line {
  width: 60px;
  height: 1px;
  background: var(--border);
  position: relative;
  overflow: hidden;
}

.scroll-line::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: var(--accent);
  animation: scrollLine 2s ease-in-out infinite;
}

@keyframes scrollLine {
  0% { left: -100%; }
  50% { left: 100%; }
  50.01% { left: -100%; }
  100% { left: -100%; }
}

/* ============================================
   HORIZONTAL SCROLL PROJECTS
   ============================================ */
.projects {
  position: relative;
  height: 300vh; /* Creates scrollable area */
  background: var(--surface);
}

.projects-container {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
}

.projects-header {
  padding: 0 10vw;
  margin-bottom: 3rem;
}

.section-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.3em;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: clamp(2rem, 5vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.projects-track {
  display: flex;
  gap: 2rem;
  padding: 0 10vw;
  will-change: transform;
}

.project-card {
  flex-shrink: 0;
  width: clamp(300px, 35vw, 500px);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2.5rem;
  text-decoration: none;
  color: var(--text);
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.project-card:hover {
  border-color: var(--accent);
  transform: translateY(-10px) scale(1.02);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(59, 130, 246, 0.2);
}

.project-card:hover::before {
  opacity: 1;
}

.project-card--featured {
  width: clamp(375px, 44vw, 625px);
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, var(--bg) 100%);
}

.project-meta {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  margin-bottom: 1rem;
}

.project-year {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.project-type {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  padding: 0.4rem 1rem;
  background: rgba(59, 130, 246, 0.1);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: 50px;
}

.project-title {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.project-desc {
  font-size: 0.9375rem;
  color: var(--text-dim);
  line-height: 1.7;
  margin-bottom: 2rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.project-tags span {
  font-size: 0.7rem;
  padding: 0.4rem 0.875rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--text-dim);
  font-weight: 500;
  transition: all 0.3s ease;
}

.project-card:hover .project-tags span {
  border-color: rgba(59, 130, 246, 0.3);
}

.project-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.875rem;
  color: var(--text-dim);
  transition: color 0.3s ease;
}

.project-card:hover .project-link {
  color: var(--accent);
}

.project-link svg {
  width: 20px;
  height: 20px;
  transition: transform 0.3s ease;
}

.project-card:hover .project-link svg {
  transform: translate(5px, -5px);
}

/* Projects scroll indicator */
.projects-scroll {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 2rem 10vw 0;
}

.projects-scroll span {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-dim);
}

.projects-scroll .scroll-line {
  width: 60px;
  height: 1px;
  background: var(--border);
  position: relative;
  overflow: hidden;
}

.projects-scroll .scroll-line::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: var(--accent);
  animation: scrollLine 2s ease-in-out infinite;
}

/* ============================================
   ABOUT SECTION
   ============================================ */
.about {
  padding: 15vh 10vw;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8rem;
  align-items: center;
}

.about-content h2 {
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 2rem;
  line-height: 1.1;
}

.about-content p {
  font-size: 1.125rem;
  color: var(--text-dim);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.about-content p strong {
  color: var(--text);
}

.text-link {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease;
}

.text-link:hover {
  border-bottom-color: var(--accent);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 3rem;
}

.stat {
  text-align: center;
  padding: 1.5rem 0;
}

.stat-value {
  display: block;
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-dim);
  line-height: 1.4;
}

/* ============================================
   R&D PROJECTS SECTION
   ============================================ */
.rd-projects {
  padding: 10vh 10vw;
}

.rd-projects-header {
  margin-bottom: 4rem;
}

.rd-projects-intro {
  font-size: 1.125rem;
  color: var(--text-dim);
  max-width: 600px;
  line-height: 1.7;
  margin-top: 1.5rem;
}

.rd-projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.rd-project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  transition: all 0.3s ease;
}

.rd-project-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.rd-project-program {
  display: inline-block;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  padding: 0.25rem 0.6rem;
  background: rgba(59, 130, 246, 0.1);
  border-radius: 50px;
  margin-bottom: 1rem;
}

.rd-project-name {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.rd-project-desc {
  font-size: 0.875rem;
  color: var(--text-dim);
  line-height: 1.5;
  margin-bottom: 1rem;
}

.rd-project-year {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.rd-project-card-link {
  text-decoration: none;
  color: inherit;
  display: block;
}

.rd-project-card-link .rd-project-card {
  position: relative;
}

.rd-project-link-icon {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 18px;
  height: 18px;
  color: var(--text-dim);
  opacity: 0.5;
  transition: all 0.3s ease;
}

.rd-project-card-link:hover .rd-project-link-icon {
  opacity: 1;
  transform: translate(2px, -2px);
  color: var(--accent);
}

/* ============================================
   CONTACT SECTION
   ============================================ */
.contact {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 10vh 10vw;
  position: relative;
}

.contact-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.3em;
  color: var(--text-dim);
  margin-bottom: 2rem;
}

.contact-title {
  font-size: clamp(3rem, 10vw, 8rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  margin-bottom: 2rem;
  line-height: 1;
}

.contact-subtitle {
  font-size: 1.25rem;
  color: var(--text-dim);
  margin-bottom: 3rem;
  max-width: 500px;
}

.contact-email {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  font-size: 1.25rem;
  color: var(--text);
  text-decoration: none;
  padding: 1.25rem 3rem;
  border: 1px solid var(--border);
  border-radius: 50px;
  transition: all 0.4s ease;
}

.contact-email:hover {
  border-color: var(--accent);
  background: var(--accent);
  box-shadow: 0 0 50px var(--accent-glow);
}

.contact-email svg {
  width: 24px;
  height: 24px;
}

.contact-location {
  margin-top: 4rem;
  font-size: 0.875rem;
  color: var(--text-dim);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  padding: 3rem 10vw;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--border);
}

.footer-left {
  font-size: 0.875rem;
  color: var(--text-dim);
}

.footer-social {
  display: flex;
  gap: 1.5rem;
}

.footer-social a {
  color: var(--text-dim);
  transition: color 0.3s ease, transform 0.3s ease;
}

.footer-social a:hover {
  color: var(--accent);
  transform: translateY(-3px);
}

.footer-social svg {
  width: 20px;
  height: 20px;
}

/* ============================================
   TOP BAR (Theme + Language)
   ============================================ */
.top-bar {
  position: fixed;
  top: 1.5rem;
  right: 2rem;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 50px;
  padding: 0.25rem;
}

.theme-toggle {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: 50%;
  border: none;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  background: rgba(59, 130, 246, 0.1);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
  color: var(--text);
  transition: transform 0.3s ease;
}

.theme-toggle:hover svg {
  transform: rotate(15deg);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.theme-toggle .icon-sun {
  display: none;
}

.theme-toggle .icon-moon {
  display: block;
}

[data-theme="light"] .theme-toggle .icon-sun {
  display: block;
}

[data-theme="light"] .theme-toggle .icon-moon {
  display: none;
}

.lang-switch {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-dim);
  text-decoration: none;
  transition: all 0.3s ease;
}

.lang-switch:hover {
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent);
}

.theme-label-dark,
.theme-label-light {
  display: none;
}

/* Light mode specific overrides */
[data-theme="light"] .name-line {
  background: linear-gradient(135deg, #171717 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="light"] .btn-primary::before {
  background: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .project-card {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .project-card:hover {
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.15), 0 0 0 1px rgba(37, 99, 235, 0.2);
}

[data-theme="light"] .blog-section-header:hover {
  background: rgba(0, 0, 0, 0.03);
}

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

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Reveal animations */
.reveal {
  opacity: 0;
  transform: translateY(50px);
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-child {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal-child.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1024px) {
  .about {
    grid-template-columns: 1fr;
    gap: 4rem;
  }

  .about-stats {
    max-width: 500px;
  }
}

@media (max-width: 768px) {
  .hero {
    padding: 0 6vw;
    min-height: auto;
    padding-top: 15vh;
    padding-bottom: 10vh;
  }

  .hero-scroll {
    display: none;
  }

  .hero-name {
    font-size: clamp(2.5rem, 14vw, 5rem);
    line-height: 1.2;
  }

  .hero-name .name-line:first-child {
    font-size: 0.85em;
    word-spacing: 4px;
  }

  /* Ensure name shows on mobile */
  .name-line {
    min-height: auto;
  }

  .name-line::before {
    display: none;
  }

  /* Disable sticky horizontal scroll on mobile */
  .projects {
    height: auto;
    padding: 8vh 0;
  }

  .projects-container {
    position: relative;
    height: auto;
    overflow: visible;
  }

  .projects-header {
    padding: 0 6vw;
    margin-bottom: 2rem;
  }

  .projects-track {
    padding: 0 6vw;
    overflow-x: auto;
    overflow-y: hidden;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: 1rem;
  }

  .projects-track::-webkit-scrollbar {
    display: none;
  }

  .project-card {
    width: 80vw;
    min-width: 280px;
    max-width: 350px;
    scroll-snap-align: start;
    padding: 1.5rem;
  }

  .project-card--featured {
    width: 85vw;
    max-width: 380px;
  }

  .project-title {
    font-size: 1.5rem;
  }

  .project-desc {
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
  }

  .project-tags {
    margin-bottom: 1.5rem;
  }

  .projects-scroll {
    display: none;
  }

  .about {
    padding: 8vh 6vw;
  }

  .about-content h2 {
    font-size: clamp(1.75rem, 6vw, 2.5rem);
  }

  .about-content p {
    font-size: 1rem;
  }

  .about-stats {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }

  .stat-value {
    font-size: 2.5rem;
  }

  .stat-label {
    font-size: 0.75rem;
  }

  .rd-projects {
    padding: 8vh 6vw;
  }

  .rd-projects-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .rd-project-card {
    padding: 1.25rem;
  }

  .contact {
    padding: 8vh 6vw;
    min-height: auto;
  }

  .contact-title {
    font-size: clamp(2rem, 12vw, 4rem);
  }

  .contact-subtitle {
    font-size: 1rem;
  }

  .footer {
    flex-direction: column;
    gap: 2rem;
    text-align: center;
    padding: 3rem 6vw;
  }

  .hero-cta {
    flex-direction: column;
    gap: 1rem;
  }

  .btn {
    justify-content: center;
    padding: 0.875rem 2rem;
    font-size: 0.8125rem;
  }

  .top-bar {
    top: 1rem;
    right: 1rem;
  }

  /* Ensure sections are visible on mobile */
  .about,
  .rd-projects,
  .contact,
  .footer {
    position: relative;
    z-index: 1;
  }

  /* Simpler reveal on mobile - show immediately */
  .reveal {
    opacity: 1;
    transform: none;
  }

  .reveal-child {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 480px) {
  .stat-value {
    font-size: 2.5rem;
  }

  .contact-email {
    font-size: 1rem;
    padding: 1rem 2rem;
  }
}