/* ============================================
   DUALITY — Humanity × Technology
   ============================================ */

/* ============================================
   1. Design Tokens
   ============================================ */
:root {
  --bg: #F7F6F3;
  --bg-alt: #EEEDEA;
  --bg-card: #FFFFFF;
  --text: #1A1A1A;
  --text-secondary: #6B6B6B;
  --text-muted: #A0A0A0;
  --warm: #C8A87C;
  --cool: #4A6FA5;
  --warm-soft: rgba(200, 168, 124, 0.12);
  --cool-soft: rgba(74, 111, 165, 0.10);
  --border: rgba(0, 0, 0, 0.08);
  --glow: radial-gradient(600px circle, rgba(200, 168, 124, 0.07), rgba(74, 111, 165, 0.05), transparent 70%);

  --font-display: 'Cormorant Garamond', 'Georgia', serif;
  --font-body: 'Inter', 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'Space Mono', monospace;

  --header-h: 64px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --transition: 0.4s var(--ease);
}

[data-theme="dark"] {
  --bg: #0E0E11;
  --bg-alt: #151518;
  --bg-card: #1A1A1E;
  --text: #E8E6E1;
  --text-secondary: #8A8A8A;
  --text-muted: #555;
  --warm: #D4B88A;
  --cool: #7DA1D4;
  --warm-soft: rgba(212, 184, 138, 0.08);
  --cool-soft: rgba(125, 161, 212, 0.08);
  --border: rgba(255, 255, 255, 0.06);
  --glow: radial-gradient(600px circle, rgba(212, 184, 138, 0.04), rgba(125, 161, 212, 0.03), transparent 70%);
}

/* ============================================
   2. Reset & Base
   ============================================ */
*, *::before, *::after { box-sizing: border-box; }
body, h1, h2, h3, p, ul, ol, figure { margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 32px);
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: color 0.5s ease, background 0.5s ease;
}

::selection {
  background-color: rgba(74, 111, 165, 0.2);
}

a { color: var(--cool); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--warm); }
img { max-width: 100%; height: auto; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* ============================================
   3. Cursor Glow
   ============================================ */
.cursor-glow {
  position: fixed;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: var(--glow);
  pointer-events: none;
  z-index: 0;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s ease;
  opacity: 0;
}

.cursor-glow.active {
  opacity: 1;
}

/* ============================================
   4. Header
   ============================================ */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--header-h);
  transition: background 0.5s ease, box-shadow 0.5s ease;
}

.header.scrolled {
  background: rgba(247, 246, 243, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--border);
}

[data-theme="dark"] .header.scrolled {
  background: rgba(14, 14, 17, 0.85);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 48px;
  display: flex;
  align-items: center;
  height: 100%;
}

.header-name {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.05em;
}

.header-name:hover { color: var(--cool); }

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
  margin-left: auto;
  margin-right: 16px;
}

.nav-link {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  position: relative;
  padding: 4px 0;
  transition: color var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 1px;
  background: linear-gradient(to right, var(--warm), var(--cool));
  transition: width var(--transition);
}

.nav-link:hover, .nav-link.active { color: var(--text); }
.nav-link:hover::after, .nav-link.active::after { width: 100%; }

.theme-toggle {
  padding: 8px;
  border-radius: 50%;
  color: var(--text-muted);
  transition: color var(--transition), background var(--transition);
  display: flex;
  align-items: center;
}

.theme-toggle:hover { color: var(--cool); background: var(--cool-soft); }

.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  width: 36px; height: 36px;
  justify-content: center;
}

.menu-toggle span {
  display: block;
  width: 20px; height: 1.5px;
  background: var(--text);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

.menu-toggle.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ============================================
   5. Hero
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  padding: 120px 32px 80px;
}

/* Duality Symbol */
.duality-symbol {
  position: relative;
  width: 280px;
  height: 280px;
  margin: 0 auto 48px;
}

.duality-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.duality-organic {
  stroke: var(--warm);
  opacity: 0.5;
  animation: breathe 6s ease-in-out infinite;
}

.duality-geometric {
  stroke: var(--cool);
  opacity: 0.5;
  animation: breathe 6s ease-in-out infinite 3s;
}

.duality-center {
  fill: var(--text);
  opacity: 0.3;
}

@keyframes breathe {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 0.7; }
}

/* Rotating orbit text */
.orbit-text {
  position: absolute;
  inset: -30px;
  animation: orbit 30s linear infinite;
}

.orbit-text svg {
  width: 100%;
  height: 100%;
}

.orbit-text-content {
  font-family: var(--font-mono);
  font-size: 9px;
  fill: var(--text-muted);
  letter-spacing: 0.25em;
  text-transform: uppercase;
}

@keyframes orbit {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* Hero typography */
.hero-name {
  margin-bottom: 32px;
}

.hero-name-en {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(3rem, 6vw, 5.5rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.hero-name-cn {
  display: block;
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--text-muted);
  letter-spacing: 0.4em;
  margin-top: 12px;
}

/* Hero divider — organic line | dot | geometric line */
.hero-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin: 32px auto;
}

.divider-organic {
  width: 48px;
  height: 1px;
  background: var(--warm);
  opacity: 0.5;
  border-radius: 1px;
}

.divider-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--warm), var(--cool));
}

.divider-geometric {
  width: 48px;
  height: 1px;
  background: var(--cool);
  opacity: 0.5;
}

/* Hero tagline */
.hero-tagline {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 400;
  font-style: italic;
  color: var(--text-secondary);
  letter-spacing: 0.03em;
}

/* ============================================
   6. Interlude — philosophical bridge
   ============================================ */
.interlude {
  padding: 120px 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
  overflow: hidden;
}

.interlude-inner {
  text-align: center;
  position: relative;
}

/* Morphing shape: circle ↔ square */
.shape-morph {
  width: 120px;
  height: 120px;
  margin: 0 auto 40px;
  border: 1px solid var(--border);
  animation: morph 8s ease-in-out infinite;
  transition: border-color 0.5s ease;
  background: linear-gradient(135deg, var(--warm-soft), var(--cool-soft));
}

@keyframes morph {
  0%, 100% {
    border-radius: 50%;
    transform: rotate(0deg) scale(1);
  }
  25% {
    border-radius: 50% 20% 50% 20%;
    transform: rotate(45deg) scale(1.05);
  }
  50% {
    border-radius: 8px;
    transform: rotate(90deg) scale(1);
  }
  75% {
    border-radius: 20% 50% 20% 50%;
    transform: rotate(135deg) scale(1.05);
  }
}


/* ============================================
   7. About Section
   ============================================ */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 48px;
}

.section {
  position: relative;
  z-index: 1;
  padding: 100px 0;
}

.about-layout {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

/* Photo with rotating orbit */
.about-photo-wrapper {
  position: relative;
  width: 300px;
  height: 300px;
  margin-bottom: 56px;
}

.photo-orbit {
  position: absolute;
  inset: -10px;
  animation: orbit 25s linear infinite;
}

.photo-orbit svg {
  width: 100%;
  height: 100%;
}

.photo-orbit-text {
  font-family: var(--font-mono);
  font-size: 8.5px;
  fill: var(--text-muted);
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.photo-container {
  position: absolute;
  inset: 20px;
  border-radius: 50%;
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(0,0,0,0.08);
  transition: transform 0.6s var(--ease), box-shadow 0.6s var(--ease);
}

[data-theme="dark"] .photo-container {
  box-shadow: 0 16px 48px rgba(0,0,0,0.3);
}

.photo-container:hover {
  transform: scale(1.03);
  box-shadow: 0 20px 60px rgba(0,0,0,0.12);
}

.photo-container img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Bio */
.about-text {
  max-width: 640px;
}

.bio p {
  margin-bottom: 20px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.85;
}

.bio p:first-child {
  color: var(--text);
  font-size: 1.05rem;
}

.bio p:last-child {
  margin-bottom: 0;
}

/* ============================================
   8. Cards Section — CV & Contact
   ============================================ */
.cards-section {
  padding: 60px 0 120px;
}

.cards-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

/* 3D Tilt Card */
.tilt-card {
  perspective: 800px;
}

.card-inner {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 48px 40px;
  text-align: center;
  overflow: hidden;
  transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease);
  transform-style: preserve-3d;
  box-shadow: 0 4px 24px rgba(0,0,0,0.03);
}

.card-inner:hover {
  box-shadow: 0 16px 48px rgba(0,0,0,0.08);
}

[data-theme="dark"] .card-inner:hover {
  box-shadow: 0 16px 48px rgba(0,0,0,0.3);
}

.card-icon {
  color: var(--text-muted);
  margin-bottom: 24px;
  transition: color var(--transition), transform var(--transition);
}

.card-inner:hover .card-icon {
  color: var(--cool);
  transform: translateY(-4px) rotateY(180deg);
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.card-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 32px;
  line-height: 1.7;
}

.card-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 28px;
  background: linear-gradient(135deg, var(--warm), var(--cool));
  color: #fff;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  transition: transform var(--transition), box-shadow var(--transition);
  box-shadow: 0 4px 16px rgba(74, 111, 165, 0.2);
}

.card-btn:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(74, 111, 165, 0.3);
}

/* Card background patterns */
.card-pattern {
  position: absolute;
  width: 200px;
  height: 200px;
  opacity: 0.15;
  z-index: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.card-inner:hover .card-pattern {
  opacity: 0.25;
}

.card-pattern-organic {
  bottom: -40px;
  right: -40px;
  border-radius: 50%;
  border: 1px solid var(--warm);
  animation: breathe 6s ease-in-out infinite;
}

.card-pattern-geometric {
  bottom: -40px;
  right: -40px;
  border: 1px solid var(--cool);
  transform: rotate(45deg);
  animation: breathe 6s ease-in-out infinite 3s;
}

/* Contact card specifics */
.contact-email {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 8px;
  transition: color var(--transition);
}

.contact-email:hover {
  color: var(--cool);
}

.contact-affiliation {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 24px;
}

.contact-info {
  margin-bottom: 8px;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 16px;
}

.social-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  color: var(--text-muted);
  border: 1px solid var(--border);
  transition: color var(--transition), border-color var(--transition), transform var(--transition), background var(--transition);
}

.social-icon:hover {
  color: var(--cool);
  border-color: var(--cool);
  background: var(--cool-soft);
  transform: translateY(-3px) rotate(5deg);
}

/* ============================================
   9. Footer
   ============================================ */
.footer {
  position: relative;
  z-index: 1;
  padding: 48px 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.footer-duality {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-size: 1rem;
  font-style: italic;
}

.footer-organic { color: var(--warm); }
.footer-dot { color: var(--text-muted); }
.footer-geometric { color: var(--cool); }

.footer p {
  color: var(--text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

/* ============================================
   10. Scroll Reveal
   ============================================ */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.9s var(--ease), transform 0.9s var(--ease);
}

[data-reveal].revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   11. Media Queries
   ============================================ */
@media (max-width: 768px) {
  .container, .header-inner {
    padding: 0 24px;
  }

  .hero-content { padding: 100px 24px 60px; }

  .duality-symbol { width: 200px; height: 200px; }

  .hero-name-en { font-size: 2.8rem; }

  .cards-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .about-photo-wrapper {
    width: 240px; height: 240px;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    background: var(--bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition), opacity var(--transition);
  }

  .nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .menu-toggle { display: flex; }

  .interlude { padding: 80px 24px; }

  .section { padding: 60px 0; }
}

@media (max-width: 480px) {
  .hero-name-en { font-size: 2.2rem; }
  .hero-name-cn { font-size: 1rem; letter-spacing: 0.3em; }
  .duality-symbol { width: 160px; height: 160px; margin-bottom: 32px; }
  .card-inner { padding: 36px 24px; }
  .about-photo-wrapper { width: 200px; height: 200px; }
}

/* ============================================
   12. Print
   ============================================ */
@media print {
  .cursor-glow, .header, .orbit-text, .photo-orbit,
  .duality-symbol, .interlude, .card-pattern, .theme-toggle { display: none !important; }
  .hero { min-height: auto; padding: 32px 0; }
  [data-reveal] { opacity: 1; transform: none; }
}