/* =============================================
   Custom Properties
   ============================================= */
:root {
  --bg:          #F7F9FF;
  --bg-alt:      #EEF2FF;
  --surface:     #FFFFFF;
  --primary:     #0D9488;
  --primary-lt:  #14B8A6;
  --primary-dim: #F0FDFA;
  --cyan:        #0891B2;
  --text:        #0F172A;
  --muted:       #64748B;
  --border:      #E2E8F0;
  --shadow:      rgba(13, 148, 136, 0.12);

  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', monospace;

  --nav-h:    64px;
  --max-w:    1100px;
  --sec-pad:  100px;
  --r-sm:     8px;
  --r-md:     12px;
  --r-lg:     20px;
  --ease:     0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body.dark-theme {
  --bg:          #071312;
  --bg-alt:      #0B1F1D;
  --surface:     #102522;
  --primary:     #2DD4BF;
  --primary-lt:  #5EEAD4;
  --primary-dim: rgba(45, 212, 191, 0.12);
  --cyan:        #67E8F9;
  --text:        #E6FFFA;
  --muted:       #94A3B8;
  --border:      rgba(148, 163, 184, 0.22);
  --shadow:      rgba(45, 212, 191, 0.14);
}

/* =============================================
   Custom Cursor
   ============================================= */
@media (hover: hover) {
  *, a, button { cursor: none !important; }
}

#cursor-dot {
  position: fixed;
  top: 0; left: 0;
  width: 8px; height: 8px;
  margin: -4px 0 0 -4px;
  background: var(--primary);
  border-radius: 50%;
  pointer-events: none;
  z-index: 10000;
  transition: opacity 0.3s, transform 0.08s;
  will-change: transform;
}

#cursor-ring {
  position: fixed;
  top: 0; left: 0;
  width: 40px; height: 40px;
  margin: -20px 0 0 -20px;
  border: 1.5px solid var(--primary);
  border-radius: 50%;
  pointer-events: none;
  z-index: 9999;
  transition: width 0.35s ease, height 0.35s ease,
              margin 0.35s ease, background 0.35s ease,
              border-color 0.35s ease, opacity 0.3s;
  will-change: transform;
}

#cursor-ring.hover {
  width: 64px; height: 64px;
  margin: -32px 0 0 -32px;
  background: rgba(13, 148, 136, 0.09);
}

#cursor-ring.click {
  width: 28px; height: 28px;
  margin: -14px 0 0 -14px;
  background: rgba(13, 148, 136, 0.22);
}

/* Distortion canvas — fixed full-screen WebGL overlay */
#distortion-canvas {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 1;
}

/* Magnetic buttons — let JS drive transform, remove CSS hover translate */
.btn-primary:hover,
.btn-outline:hover {
  transform: none;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 32px);
  font-size: 16px;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background var(--ease), color var(--ease);
}

a { color: var(--primary); text-decoration: none; transition: color var(--ease); }
a:hover { color: var(--primary-lt); }
ul { list-style: none; }

/* =============================================
   Layout
   ============================================= */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
section {
  padding: var(--sec-pad) 0;
  scroll-margin-top: calc(var(--nav-h) + 32px);
}
.section-alt { background: var(--bg-alt); }

.section-header { margin-bottom: 52px; }

.section-label {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--primary);
  background: var(--primary-dim);
  padding: 4px 12px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 14px;
}

.section-header h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
}

/* =============================================
   Scroll Reveal
   ============================================= */
.reveal {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.js-loaded .reveal {
  opacity: 0;
  transform: translateY(28px);
}
.js-loaded .reveal.visible { opacity: 1; transform: translateY(0); }

/* =============================================
   Navigation
   ============================================= */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 1000;
  transition: background var(--ease), box-shadow var(--ease);
}

#navbar.scrolled {
  background: rgba(255, 255, 255, 0.90);
  backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--border);
}

body.dark-theme #navbar.scrolled {
  background: rgba(7, 19, 18, 0.88);
}

.nav-container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  width: 38px; height: 38px;
  border-radius: var(--r-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  transition: transform var(--ease);
}
.nav-logo img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
}
.nav-logo:hover { transform: scale(1.07); }

.nav-links { display: flex; gap: 4px; }

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.88);
  padding: 6px 12px;
  border-radius: var(--r-sm);
  transition: color var(--ease), background var(--ease);
}

#navbar.scrolled .nav-links a { color: var(--muted); }

.nav-links a:hover {
  color: var(--primary);
  background: var(--primary-dim);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  display: block;
  width: 22px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--ease), opacity var(--ease);
}

/* =============================================
   Hero
   ============================================= */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--nav-h) 24px 48px;
  overflow: hidden;
  background: linear-gradient(135deg, #0D9488 0%, #0891B2 55%, #06B6D4 100%);
}

#hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 50% 42%, rgba(15, 23, 42, 0.42), rgba(15, 23, 42, 0.18) 34%, transparent 62%),
    linear-gradient(180deg, rgba(15, 23, 42, 0.26), rgba(15, 23, 42, 0.12));
  pointer-events: none;
  z-index: 1;
}

#hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 700px;
  text-align: center;
  text-shadow: 0 2px 18px rgba(15, 23, 42, 0.28);
}

.hero-badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 500;
  color: #fff;
  background: rgba(15, 23, 42, 0.20);
  border: 1px solid rgba(255, 255, 255, 0.34);
  backdrop-filter: blur(8px);
  padding: 6px 18px;
  border-radius: 100px;
  margin-bottom: 26px;
  letter-spacing: 0.05em;
}

.hero-name {
  font-size: clamp(2.75rem, 6vw, 4.25rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.hero-sub {
  font-size: clamp(0.82rem, 1.8vw, 0.92rem);
  font-family: var(--mono);
  color: rgba(255, 255, 255, 0.86);
  margin-bottom: 22px;
  letter-spacing: 0.04em;
}

.hero-desc {
  font-size: 1.0625rem;
  color: rgba(255, 255, 255, 0.95);
  line-height: 1.75;
  margin: 0 auto 36px;
  max-width: 560px;
}

.hero-cta {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  border-radius: var(--r-md);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--ease);
}

.btn-primary {
  background: #fff;
  color: var(--primary);
}
.btn-primary:hover {
  background: var(--primary-dim);
  color: var(--primary);
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.16);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.38);
  backdrop-filter: blur(8px);
}
.btn-outline:hover {
  background: rgba(255, 255, 255, 0.24);
  color: #fff;
  transform: translateY(-2px);
}

.hero-socials {
  display: flex;
  gap: 10px;
  justify-content: center;
  align-items: center;
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.55);
}
.hero-socials a {
  color: rgba(255, 255, 255, 0.82);
  font-weight: 500;
}
.hero-socials a:hover { color: #fff; }

.hero-mode-hint {
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.86);
  letter-spacing: 0.04em;
}

.hero-scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.45);
  font-size: 0.65rem;
  font-family: var(--mono);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  z-index: 2;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, rgba(255,255,255,0.55), transparent);
  animation: pulse 2.2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

/* =============================================
   About
   ============================================= */
.about-grid {
  display: grid;
  grid-template-columns: 220px 1fr 320px;
  gap: 52px;
  align-items: start;
}

.about-photo {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  position: sticky;
  top: calc(var(--nav-h) + 24px);
}

.photo-frame {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 4px solid var(--primary-dim);
  outline: 2px solid var(--primary);
  position: relative;
  background: transparent;
  perspective: 900px;
  transition: box-shadow var(--ease), outline-color var(--ease);
}

.photo-frame:hover,
.photo-frame:focus-within {
  box-shadow: 0 18px 44px var(--shadow);
}

.photo-flip-inner {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  transform-style: preserve-3d;
  transition: transform 0.75s cubic-bezier(0.23, 1, 0.32, 1);
}

.photo-frame:hover .photo-flip-inner,
.photo-frame:focus-within .photo-flip-inner,
.photo-frame:focus .photo-flip-inner {
  transform: rotateY(180deg);
}

.photo-face {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  overflow: hidden;
  backface-visibility: hidden;
  background: var(--bg-alt);
}

.photo-front {
  transform: rotateY(0deg);
}

.photo-back {
  transform: rotateY(180deg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 22px;
  text-align: center;
  background:
    radial-gradient(circle at 50% 30%, rgba(94, 234, 212, 0.24), transparent 45%),
    linear-gradient(135deg, var(--primary), var(--cyan));
  color: #fff;
}

.photo-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  position: relative;
  z-index: 1;
}

.photo-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  color: var(--border);
}

.photo-frame.photo-missing img { display: none; }

.theme-question {
  font-size: 0.95rem;
  font-weight: 800;
  line-height: 1.2;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: rgba(15, 23, 42, 0.22);
  color: #fff;
  border-radius: 100px;
  padding: 7px 9px 7px 12px;
  font-family: var(--font);
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
  backdrop-filter: blur(10px);
}

.theme-toggle-track {
  width: 32px;
  height: 18px;
  border-radius: 100px;
  background: rgba(255, 255, 255, 0.28);
  padding: 2px;
  display: flex;
  align-items: center;
  transition: background var(--ease);
}

.theme-toggle-track span {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #fff;
  transform: translateX(0);
  transition: transform var(--ease);
}

body.dark-theme .theme-toggle-track {
  background: rgba(15, 23, 42, 0.56);
}

body.dark-theme .theme-toggle-track span {
  transform: translateX(14px);
}

.photo-socials {
  display: flex;
  gap: 10px;
}

.photo-socials a {
  width: 34px; height: 34px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  transition: all var(--ease);
}
.photo-socials a:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: var(--primary-dim);
}

.about-text p {
  color: var(--muted);
  font-size: 1.0625rem;
  line-height: 1.8;
  margin-bottom: 16px;
}
.about-text strong { color: var(--text); font-weight: 600; }
.about-text em { color: var(--primary); font-style: normal; font-weight: 500; }

.about-edu {
  margin-top: 28px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.edu-item {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-left: 14px;
  border-left: 2px solid var(--primary-dim);
}

.edu-degree {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text);
}

.edu-school {
  font-size: 0.8125rem;
  color: var(--muted);
}

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: transform var(--ease), box-shadow var(--ease);
}
.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 14px 36px var(--shadow);
}

.stat-number {
  font-size: 2.1rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-size: 0.78rem;
  color: var(--muted);
  font-weight: 500;
}

/* =============================================
   Publications
   ============================================= */
#research {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 18% 18%, rgba(20, 184, 166, 0.12), transparent 30%),
    radial-gradient(circle at 82% 70%, rgba(8, 145, 178, 0.10), transparent 34%),
    linear-gradient(135deg, #F7F9FF 0%, #FFFFFF 52%, #F0FDFA 100%);
  color: var(--text);
}

body.dark-theme #research {
  background:
    radial-gradient(circle at 18% 18%, rgba(20, 184, 166, 0.16), transparent 30%),
    radial-gradient(circle at 82% 70%, rgba(8, 145, 178, 0.14), transparent 34%),
    linear-gradient(135deg, #081817 0%, #0B2623 48%, #071312 100%);
  color: #E6FFFA;
}

#research .container {
  position: relative;
  z-index: 2;
}

#research .section-label {
  color: var(--primary);
  background: var(--primary-dim);
  border: 1px solid rgba(20, 184, 166, 0.18);
}

#research .section-header h2 {
  color: var(--text);
}

body.dark-theme #research .section-label {
  color: #A7F3D0;
  background: rgba(20, 184, 166, 0.14);
  border: 1px solid rgba(167, 243, 208, 0.18);
}

body.dark-theme #research .section-header h2 {
  color: #F0FDFA;
}

#research-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.92;
  z-index: 0;
}

.pub-list {
  position: relative;
  min-height: 620px;
  margin: 0 auto;
  overflow: visible;
}

.planet-label {
  position: absolute;
  z-index: 3;
  transform: translate(-50%, -50%);
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 800;
  color: #fff;
  text-shadow: 0 1px 8px rgba(15, 23, 42, 0.8);
  pointer-events: none;
  user-select: none;
  opacity: 0.9;
}

.planet-label.research-planet {
  color: #FEF3C7;
  letter-spacing: 0.03em;
}

.pub-card {
  position: absolute;
  right: clamp(8px, 1.2vw, 22px);
  top: 58%;
  width: clamp(250px, 26vw, 330px);
  background: rgba(255, 255, 255, 0.54);
  border: 1px solid rgba(13, 148, 136, 0.18);
  border-radius: var(--r-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  align-items: flex-start;
  backdrop-filter: blur(8px);
  opacity: 0;
  pointer-events: none;
  transform: translateY(-50%) translateX(22px) scale(0.96);
  transition: opacity var(--ease), transform var(--ease), box-shadow var(--ease), border-color var(--ease), background var(--ease);
}

.pub-close {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid rgba(13, 148, 136, 0.20);
  background: rgba(255, 255, 255, 0.7);
  color: var(--muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  transition: background var(--ease), color var(--ease), transform var(--ease), border-color var(--ease);
}

.pub-close:hover,
.pub-close:focus-visible {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  transform: scale(1.08);
}

.pub-card:hover {
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 24px 60px rgba(13, 148, 136, 0.14);
  border-color: rgba(94, 234, 212, 0.48);
}

.pub-card.active {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(-50%) translateX(0) scale(1);
  z-index: 6;
}

.js-loaded #research .pub-card.reveal.visible {
  opacity: 0;
  transform: translateY(-50%) translateX(22px) scale(0.96);
}

.js-loaded #research .pub-card.reveal.visible.active {
  opacity: 1;
  transform: translateY(-50%) translateX(0) scale(1);
}

.research-hint {
  position: absolute;
  left: clamp(0px, 0.6vw, 10px);
  top: 50%;
  max-width: 145px;
  z-index: 3;
  margin-top: 0;
  transform: translateY(-50%);
  text-align: left;
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--muted);
  line-height: 1.55;
  padding: 10px 12px;
  border-left: 2px solid rgba(13, 148, 136, 0.35);
  background: rgba(255, 255, 255, 0.48);
  border-radius: var(--r-sm);
  backdrop-filter: blur(8px);
}

body.dark-theme .research-hint {
  color: rgba(203, 213, 225, 0.82);
  background: rgba(15, 23, 42, 0.28);
  border-left-color: rgba(167, 243, 208, 0.35);
}

.research-hint-mobile {
  display: none;
}

body.dark-theme .pub-card {
  background: rgba(15, 23, 42, 0.24);
  border: 1px solid rgba(148, 163, 184, 0.2);
}

body.dark-theme .pub-close {
  background: rgba(15, 23, 42, 0.62);
  border-color: rgba(148, 163, 184, 0.24);
  color: rgba(226, 232, 240, 0.72);
}

body.dark-theme .pub-card:hover {
  background: rgba(15, 23, 42, 0.48);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
}

.pub-meta {
  flex-shrink: 0;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  width: 100%;
}

.pub-venue {
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-dim);
  border: 1px solid rgba(20, 184, 166, 0.18);
  padding: 4px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-align: center;
}

.pub-year {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--muted);
}

.pub-body { flex: 1; display: flex; flex-direction: column; gap: 8px; }

.pub-body h3 {
  font-size: 1.0rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.45;
}

.pub-authors { font-size: 0.875rem; color: var(--muted); }

.pub-doi {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--cyan);
  font-weight: 500;
  align-self: flex-start;
}
.pub-doi:hover { color: var(--primary); }

body.dark-theme .pub-venue {
  color: #A7F3D0;
  background: rgba(20, 184, 166, 0.12);
  border: 1px solid rgba(167, 243, 208, 0.18);
}

body.dark-theme .pub-year { color: rgba(226, 232, 240, 0.66); }
body.dark-theme .pub-body h3 { color: #F8FAFC; }
body.dark-theme .pub-authors { color: rgba(203, 213, 225, 0.78); }
body.dark-theme .pub-doi { color: #67E8F9; }
body.dark-theme .pub-doi:hover { color: #A7F3D0; }

/* =============================================
   Experience / Timeline
   ============================================= */
.timeline {
  position: relative;
  display: grid;
  gap: 34px;
  padding: 8px 0;
  counter-reset: timeline;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 8px;
  bottom: 8px;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(to bottom, transparent, var(--primary), var(--primary-lt), transparent);
  box-shadow: 0 0 24px rgba(13, 148, 136, 0.26);
}

.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 64px minmax(0, 1fr);
  align-items: start;
  min-height: 128px;
  counter-increment: timeline;
}
.timeline-item:last-child { margin-bottom: 0; }

.timeline-dot {
  position: relative;
  grid-column: 2;
  justify-self: center;
  top: 22px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--surface);
  border: 2px solid var(--primary);
  box-shadow: 0 0 0 8px var(--primary-dim), 0 0 28px rgba(13, 148, 136, 0.32);
  z-index: 2;
}

.timeline-dot::after {
  content: counter(timeline);
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-family: var(--mono);
  font-size: 0.58rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.timeline-content {
  position: relative;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 24px 28px;
  transform: perspective(900px) rotateY(0deg);
  transition: transform var(--ease), box-shadow var(--ease), border-color var(--ease), background var(--ease);
}

.timeline-item:nth-child(odd) .timeline-content {
  grid-column: 1;
}

.timeline-item:nth-child(even) .timeline-content {
  grid-column: 3;
}

.timeline-content::before {
  content: '';
  position: absolute;
  top: 28px;
  width: 18px;
  height: 18px;
  background: inherit;
  border-top: 1px solid var(--border);
  border-right: 1px solid var(--border);
  transform: rotate(45deg);
}

.timeline-item:nth-child(odd) .timeline-content::before {
  right: -10px;
}

.timeline-item:nth-child(even) .timeline-content::before {
  left: -10px;
  transform: rotate(225deg);
}

.timeline-content:hover {
  background: #fff;
  border-color: rgba(20, 184, 166, 0.45);
  box-shadow: 0 18px 44px var(--shadow);
}

body.dark-theme .timeline-content,
body.dark-theme .timeline-content:hover {
  background: rgba(16, 37, 34, 0.94);
}

.timeline-item:nth-child(odd) .timeline-content:hover {
  transform: perspective(900px) rotateY(-3deg) translateY(-4px);
}

.timeline-item:nth-child(even) .timeline-content:hover {
  transform: perspective(900px) rotateY(3deg) translateY(-4px);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 6px;
}

.timeline-header h3 {
  font-size: 1.0rem;
  font-weight: 700;
  color: var(--text);
}

.timeline-period {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--primary);
  background: var(--primary-dim);
  padding: 3px 10px;
  border-radius: 100px;
  white-space: nowrap;
  flex-shrink: 0;
}

.timeline-company {
  font-size: 0.875rem;
  color: var(--muted);
  font-weight: 500;
  margin-bottom: 14px;
}

.timeline-content ul {
  list-style: disc;
  padding-left: 18px;
}

.timeline-content li {
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.65;
  margin-bottom: 6px;
}

/* =============================================
   Projects
   ============================================= */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: transform var(--ease), box-shadow var(--ease), border-color var(--ease);
}
.project-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 18px 44px var(--shadow);
  border-color: var(--primary-lt);
}

.project-fa-icon {
  font-size: 1.5rem;
  color: var(--primary);
}

.project-content h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.35;
}

.project-content p {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.65;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 2px;
}
.project-tags span {
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--primary);
  background: var(--primary-dim);
  padding: 3px 10px;
  border-radius: 100px;
}

.project-link {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--cyan);
  margin-top: 4px;
}
.project-link:hover { color: var(--primary); }

/* =============================================
   Skills
   ============================================= */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 18px;
}

.skill-group {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 22px;
}

.skill-group h4 {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.skill-group h4 i { color: var(--primary); font-size: 0.8rem; }

.skill-tags { display: flex; flex-wrap: wrap; gap: 8px; }

.skill-tags span {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 100px;
  transition: all var(--ease);
  cursor: default;
}
.skill-tags span:hover {
  color: var(--primary);
  border-color: var(--primary-lt);
  background: var(--primary-dim);
}

/* =============================================
   Contact
   ============================================= */
.contact-content {
  max-width: 580px;
  margin: 0 auto;
  text-align: center;
}

.contact-content > p {
  font-size: 1.0625rem;
  color: var(--muted);
  line-height: 1.75;
  margin-bottom: 36px;
}

.contact-links {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 22px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  color: var(--text);
  font-weight: 500;
  font-size: 0.9rem;
  transition: all var(--ease);
}
.contact-link:hover {
  color: var(--primary);
  border-color: var(--primary-lt);
  background: var(--primary-dim);
  transform: translateY(-2px);
  box-shadow: 0 10px 24px var(--shadow);
}

.contact-icon {
  width: 30px; height: 30px;
  border-radius: 7px;
  background: var(--primary-dim);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.78rem;
  font-weight: 700;
  font-family: var(--mono);
  flex-shrink: 0;
}

/* =============================================
   Footer
   ============================================= */
footer {
  background: linear-gradient(135deg, #0D9488 0%, #0891B2 62%, #06B6D4 100%);
  padding: 24px 0;
  text-align: center;
}

body.dark-theme footer {
  background: linear-gradient(135deg, #064E49 0%, #0F766E 58%, #155E75 100%);
}
footer p {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.45);
  font-family: var(--mono);
}

/* =============================================
   3D Project Carousel
   ============================================= */
.carousel-wrapper {
  position: relative;
  margin: 0 -24px;
}

#carousel-container {
  position: relative;
  height: 560px;
  overflow: hidden;
}

.carousel-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 24px 0 8px;
}

#carousel-prev,
#carousel-next {
  width: 44px; height: 44px;
  border-radius: 50%;
  border: 1.5px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.875rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--ease);
}
#carousel-prev:hover,
#carousel-next:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-dim);
}

#carousel-dots { display: flex; gap: 8px; align-items: center; }

.c-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  border: none;
  background: var(--border);
  cursor: pointer;
  padding: 0;
  transition: all var(--ease);
}
.c-dot.active {
  background: var(--primary);
  width: 22px;
  border-radius: 4px;
}

/* 3D Card (CSS3DObject element) */
.p3d-card {
  width: 340px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0,0,0,0.10);
  display: flex;
  flex-direction: column;
  cursor: pointer;
  transition: box-shadow 0.3s;
  box-sizing: border-box;
}
.p3d-card:hover { box-shadow: 0 20px 56px rgba(13,148,136,0.22); }

.p3d-img-wrap {
  width: 100%;
  height: 160px;
  overflow: hidden;
  flex-shrink: 0;
}
.p3d-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.5s ease;
}
.p3d-card:hover .p3d-img-wrap img { transform: scale(1.07); }

.p3d-body {
  padding: 20px 22px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

.p3d-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.p3d-icon { font-size: 1.4rem; color: var(--primary); }

.p3d-num {
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.1em;
}

.p3d-title {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}

.p3d-desc {
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.6;
  flex: 1;
}

.p3d-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}
.p3d-tags span {
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 500;
  color: var(--primary);
  background: var(--primary-dim);
  padding: 2px 8px;
  border-radius: 100px;
}

.p3d-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--primary);
  padding: 7px 13px;
  border: 1.5px solid var(--primary);
  border-radius: var(--r-sm);
  transition: all var(--ease);
  align-self: flex-start;
}
.p3d-link:hover { background: var(--primary); color: #fff; }

/* =============================================
   3D Skill Sphere
   ============================================= */
.skills-sphere-container {
  position: relative;
  height: 620px;
  margin: 0 -24px;
}

.skill-3d-tag {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 7px 18px;
  font-size: 0.82rem;
  font-weight: 500;
  font-family: var(--font);
  color: var(--primary);
  white-space: nowrap;
  cursor: pointer;
  pointer-events: auto;
  user-select: none;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
}
.skill-3d-tag:hover {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 6px 24px rgba(13,148,136,0.4);
}

.sphere-hint {
  text-align: center;
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

/* =============================================
   Section Sub-heading
   ============================================= */
.section-sub {
  font-size: 1.0625rem;
  color: var(--muted);
  margin-top: 10px;
  line-height: 1.6;
}

/* =============================================
   About — Awards & Certifications
   ============================================= */
.about-right { display: flex; flex-direction: column; gap: 24px; }

.about-awards {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 22px;
  margin-top: 28px;
}

.about-awards h4,
.cert-list h4 {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text);
  margin-bottom: 14px;
}

.about-awards ul { display: flex; flex-direction: column; gap: 10px; }

.about-awards li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.5;
}

.award-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--primary);
  flex-shrink: 0;
  margin-top: 6px;
}

.cert-list {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.cert-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.cert-item:last-child { border-bottom: none; padding-bottom: 0; }
.cert-item:first-of-type { padding-top: 0; }

.cert-icon-fa {
  font-size: 1rem;
  color: var(--primary);
  width: 22px;
  text-align: center;
  flex-shrink: 0;
  margin-top: 2px;
}

.cert-name {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.4;
}

.cert-year {
  display: block;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
  margin-top: 2px;
}

/* =============================================
   Projects — top row & icon links
   ============================================= */
.project-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.project-links-row { display: flex; gap: 8px; }

.icon-link {
  width: 32px; height: 32px;
  border-radius: var(--r-sm);
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--ease);
}
.icon-link:hover {
  color: var(--primary);
  border-color: var(--primary-lt);
  background: var(--primary-dim);
}

/* =============================================
   Interactive Demos
   ============================================= */
.demos-header {
  margin-top: 64px;
  margin-bottom: 28px;
}

.demos-header h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.demos-header p {
  font-size: 0.9375rem;
  color: var(--muted);
}

.demos-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}

.demo-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  color: var(--text);
  transition: transform var(--ease), box-shadow var(--ease), border-color var(--ease);
  cursor: pointer;
}
.demo-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px var(--shadow);
  border-color: var(--primary-lt);
  color: var(--text);
}

.demo-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.demo-fa-icon {
  font-size: 1.4rem;
  color: var(--primary);
}

.demo-badge {
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #059669;
  background: #ECFDF5;
  border: 1px solid #A7F3D0;
  padding: 3px 8px;
  border-radius: 100px;
}

.demo-card h4 {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}

.demo-card p {
  font-size: 0.84rem;
  color: var(--muted);
  line-height: 1.6;
  flex: 1;
}

.demo-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}
.demo-tags span {
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 500;
  color: var(--primary);
  background: var(--primary-dim);
  padding: 2px 8px;
  border-radius: 100px;
}

.demo-play {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--cyan);
  margin-top: 2px;
  transition: color var(--ease);
}
.demo-card:hover .demo-play { color: var(--primary); }

/* =============================================
   Contact — improved layout
   ============================================= */
#contact {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 100%, rgba(20, 184, 166, 0.14), transparent 42%),
    var(--bg-alt);
}

body.dark-theme #contact {
  background:
    radial-gradient(circle at 50% 100%, rgba(45, 212, 191, 0.18), transparent 42%),
    var(--bg-alt);
}

#contact .container {
  position: relative;
  z-index: 2;
}

#contact-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.75;
  z-index: 0;
}

.contact-content {
  max-width: 760px;
}

.contact-content > p {
  max-width: 620px;
  margin-left: auto;
  margin-right: auto;
}

.contact-links {
  gap: 32px;
}

.contact-link {
  position: relative;
  gap: 12px;
  padding: 10px 0 14px;
  text-align: left;
  background: transparent;
  border: 0;
  border-radius: 0;
  box-shadow: none;
}

.contact-link::after {
  content: '';
  position: absolute;
  left: 50px;
  right: 0;
  bottom: 4px;
  height: 1px;
  background: linear-gradient(90deg, var(--primary), transparent);
  transform: scaleX(0.35);
  transform-origin: left;
  opacity: 0.45;
  transition: transform var(--ease), opacity var(--ease);
}

.contact-link:hover {
  background: transparent;
  border-color: transparent;
  box-shadow: none;
  transform: translateY(-3px);
}

.contact-link:hover::after {
  transform: scaleX(1);
  opacity: 1;
}

.contact-link .contact-icon {
  width: 42px; height: 42px;
  border-radius: 50%;
  background: rgba(13, 148, 136, 0.10);
  border: 1px solid rgba(13, 148, 136, 0.22);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background var(--ease), color var(--ease), transform var(--ease), box-shadow var(--ease);
}

.contact-link:hover .contact-icon {
  background: var(--primary);
  color: #fff;
  transform: scale(1.08);
  box-shadow: 0 12px 30px rgba(13, 148, 136, 0.22);
}

.contact-label {
  display: block;
  font-size: 0.72rem;
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
  margin-bottom: 2px;
}

.contact-value {
  display: block;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
}

.contact-link--cta {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  justify-content: center;
  gap: 10px;
  font-weight: 600;
}
.contact-link--cta:hover {
  background: #4338CA;
  border-color: #4338CA;
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(79,70,229,0.35);
}

/* =============================================
   Footer
   ============================================= */
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-copy {
  display: flex;
  flex-direction: column;
  gap: 3px;
  color: rgba(255, 255, 255, 0.75);
}
.footer-copy span:last-child {
  font-size: 0.75rem;
  opacity: 0.55;
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.72);
  transition: color var(--ease);
}
.footer-links a:hover { color: #fff; }

/* =============================================
   Responsive
   ============================================= */
@media (max-width: 1100px) {
  .about-grid { grid-template-columns: 180px 1fr 280px; gap: 36px; }
  .photo-frame { width: 160px; height: 160px; }
}

@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .about-photo { grid-column: 1 / 2; grid-row: 1; }
  .about-right { grid-column: 2 / 3; grid-row: 1; }
  .about-text { grid-column: 1 / 3; grid-row: 2; }
  .about-photo { position: static; }
  .demos-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  :root { --sec-pad: 64px; }

  #carousel-container { height: 480px; }
  .p3d-card { width: 280px; }
  .p3d-img-wrap { height: 130px; }
  .skills-sphere-container { height: 420px; }

  .nav-links { display: none; }
  .nav-toggle { display: flex; }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--nav-h);
    left: 0; right: 0;
    background: var(--surface);
    padding: 16px 24px 24px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.09);
    gap: 2px;
  }
  .nav-links.open a { color: var(--muted); }

  .projects-grid { grid-template-columns: 1fr; }
  .demos-grid { grid-template-columns: 1fr 1fr; }

  .pub-card { flex-direction: column; gap: 12px; }
  .pub-meta { flex-direction: row; min-width: auto; }
  .pub-list {
    min-height: 0;
    display: grid;
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .planet-label { display: none; }
  .research-hint {
    position: relative;
    left: auto;
    top: auto;
    max-width: none;
    margin-top: 18px;
    transform: none;
    text-align: center;
    padding-left: 0;
    border-left: 0;
  }
  .research-hint-desktop { display: none; }
  .research-hint-mobile { display: inline; }
  .pub-card,
  .pub-card:hover {
    position: relative;
    left: auto;
    right: auto;
    top: auto;
    width: auto;
    opacity: 1;
    pointer-events: auto;
    transform: none;
  }
  .js-loaded #research .pub-card.reveal.visible,
  .js-loaded #research .pub-card.reveal.visible.active {
    opacity: 1;
    transform: none;
  }

  .timeline {
    gap: 28px;
    padding-left: 34px;
  }
  .timeline::before {
    left: 7px;
    transform: none;
  }
  .timeline-item {
    display: block;
    min-height: 0;
  }
  .timeline-dot {
    position: absolute;
    left: -36px;
    top: 18px;
  }
  .timeline-item:nth-child(odd) .timeline-content,
  .timeline-item:nth-child(even) .timeline-content {
    text-align: left;
  }
  .timeline-content::before,
  .timeline-item:nth-child(odd) .timeline-content::before,
  .timeline-item:nth-child(even) .timeline-content::before {
    left: -10px;
    right: auto;
    transform: rotate(225deg);
  }
  .timeline-item:nth-child(odd) .timeline-content:hover,
  .timeline-item:nth-child(even) .timeline-content:hover {
    transform: translateY(-4px);
  }

  .timeline-header { flex-direction: column; gap: 8px; }

  .contact-links { flex-direction: column; align-items: stretch; }
  .contact-link--cta { margin-top: 4px; }

  .footer-inner { flex-direction: column; text-align: center; }
}

@media (max-width: 560px) {
  .about-grid { grid-template-columns: 1fr; }
  .about-photo { grid-column: 1; grid-row: auto; }
  .about-right { grid-column: 1; grid-row: auto; }
  .about-text { grid-column: 1; grid-row: auto; }
  .demos-grid { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: 1fr 1fr; }
  .skills-grid { grid-template-columns: 1fr; }
  .hero-socials { flex-direction: column; gap: 6px; }
  .hero-socials span { display: none; }
  .hero-cta { flex-direction: column; align-items: center; }
}