/* ─── Variables ───────────────────────────────────────────────── */
:root {
  --bg:           #080b10;
  --bg-2:         #0d1117;
  --surface:      rgba(255, 255, 255, 0.025);
  --surface-2:    rgba(255, 255, 255, 0.05);
  --border:       rgba(255, 255, 255, 0.08);
  --border-hover: rgba(56, 189, 248, 0.35);
  --text:         #f1f5f9;
  --text-subtle:  #94a3b8;
  --text-muted:   #475569;
  --accent-1:     #38bdf8;
  --accent-2:     #818cf8;
  --gradient:     linear-gradient(135deg, #38bdf8, #818cf8);
  --glow-1:       rgba(56, 189, 248, 0.12);
  --glow-2:       rgba(129, 140, 248, 0.08);
  --radius:       10px;
  --radius-lg:    16px;
  --max-w:        900px;
  --nav-h:        64px;
  --ease:         cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-h);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: clip;
}

a {
  color: inherit;
  text-decoration: none;
}

ul { list-style: none; }
img { display: block; max-width: 100%; }

/* ─── Layout ──────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 28px;
}

main {
  min-height: 100vh;
  min-height: 100dvh;
}

section { padding: 100px 0; }

/* ─── Gradient utilities ──────────────────────────────────────── */
.gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ─── Nav ─────────────────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 200;
  transition: background 0.4s ease, border-color 0.4s ease;
  border-bottom: 1px solid transparent;
}

.nav.scrolled {
  background: rgba(8, 11, 16, 0.88);
  border-bottom-color: var(--border);
}

.nav.scrolled::before {
  content: '';
  position: absolute;
  inset: 0;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  z-index: -1;
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 28px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.06em;
}

.nav-brand-mark {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-brand-name {
  color: var(--text-subtle);
  transition: color 0.2s ease;
}
.nav-brand:hover .nav-brand-name { color: var(--text); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  font-size: 13.5px;
  font-weight: 400;
  color: var(--text-subtle);
  letter-spacing: 0.01em;
  position: relative;
  transition: color 0.2s ease;
  padding-bottom: 2px;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0; right: 0;
  height: 1px;
  background: var(--gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}
.nav-links a:hover::after,
.nav-links a.active::after {
  transform: scaleX(1);
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  z-index: 300;
}
.menu-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s var(--ease), opacity 0.3s ease;
}
.nav.menu-open .menu-toggle span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav.menu-open .menu-toggle span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav.menu-open .menu-toggle span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ─── Hero ────────────────────────────────────────────────────── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: var(--nav-h);
}

/* Dot grid */
.hero-grid {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(148, 163, 184, 0.1) 1px, transparent 1px);
  background-size: 28px 28px;
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, rgba(0,0,0,0.6) 0%, transparent 80%);
  mask-image: radial-gradient(ellipse 80% 80% at 50% 0%, rgba(0,0,0,0.6) 0%, transparent 80%);
  pointer-events: none;
}

/* Gradient orbs */
.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}
.hero-orb-1 {
  width: 500px; height: 500px;
  top: -100px; left: -150px;
  background: var(--glow-1);
  animation: orb-drift 12s ease-in-out infinite;
}
.hero-orb-2 {
  width: 400px; height: 400px;
  bottom: -80px; right: -100px;
  background: var(--glow-2);
  animation: orb-drift 14s ease-in-out infinite reverse;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 640px;
}

.hero-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-1);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.hero-eyebrow::before {
  content: '';
  display: block;
  width: 32px;
  height: 1px;
  background: var(--accent-1);
}

.hero-name {
  font-size: clamp(52px, 9vw, 88px);
  font-weight: 700;
  line-height: 1.0;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #f1f5f9 0%, #38bdf8 50%, #c7d2fe 100%);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient-shift 10s ease infinite;
  margin-bottom: 20px;
}

.hero-tagline {
  font-family: 'JetBrains Mono', monospace;
  font-size: clamp(13px, 2vw, 15px);
  color: var(--text-subtle);
  letter-spacing: 0.04em;
  margin-bottom: 48px;
}

.hero-cta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* Scroll indicator */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  z-index: 1;
  animation: bob 2.5s ease-in-out infinite;
}
.scroll-indicator span {
  font-family: 'JetBrains Mono', monospace;
  font-size: 9px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.scroll-line {
  width: 1px;
  height: 36px;
  background: linear-gradient(to bottom, var(--text-muted), transparent);
}

/* ─── Buttons ─────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 24px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: all 0.25s var(--ease);
  cursor: pointer;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient);
  color: #080b10;
  box-shadow: 0 0 24px rgba(56, 189, 248, 0.2);
}
.btn-primary:hover {
  box-shadow: 0 0 36px rgba(56, 189, 248, 0.35);
  transform: translateY(-1px);
}

.btn-ghost {
  border: 1px solid var(--border);
  color: var(--text-subtle);
  background: var(--surface);
}
.btn-ghost:hover {
  border-color: var(--border-hover);
  color: var(--text);
  background: var(--surface-2);
  transform: translateY(-1px);
}

/* ─── Section header ──────────────────────────────────────────── */
.section-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-1);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 56px;
}

/* ─── Page hero (inner pages) ─────────────────────────────────── */
.page-hero {
  position: relative;
  padding-top: calc(var(--nav-h) + 72px);
  padding-bottom: 72px;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: 0; left: -20%; right: -20%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  bottom: 0;
  top: auto;
}

.page-hero-orb {
  position: absolute;
  width: 400px;
  height: 400px;
  top: -150px;
  right: -100px;
  border-radius: 50%;
  background: var(--glow-2);
  filter: blur(80px);
  pointer-events: none;
}

.page-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-1);
  margin-bottom: 14px;
}

.page-title {
  font-size: clamp(40px, 6vw, 60px);
  font-weight: 700;
  letter-spacing: -0.03em;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.05;
}

/* ─── Gradient divider ────────────────────────────────────────── */
.gradient-hr {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border) 20%, var(--border) 80%, transparent);
}

/* ─── About ───────────────────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 180px;
  gap: 72px;
  align-items: start;
}

.about-bio p {
  color: var(--text-subtle);
  font-size: 16px;
  line-height: 1.85;
  margin-bottom: 18px;
}
.about-bio p:last-child { margin-bottom: 0; }

.skills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 28px;
}

.skill-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  padding: 4px 10px;
  border-radius: 6px;
  background: var(--surface);
  border: 1px solid var(--border-hover);
  color: var(--accent-1);
  letter-spacing: 0.02em;
  transition: all 0.2s ease;
}
.skill-tag:hover {
  border-color: var(--border-hover);
  color: var(--accent-1);
}

/* Profile photo with gradient ring */
.about-photo-wrapper {
  position: relative;
  width: 160px;
  height: 160px;
  flex-shrink: 0;
}
.about-photo-wrapper::before {
  content: '';
  position: absolute;
  inset: -2px;
  border-radius: 50%;
  background: var(--gradient);
  z-index: 0;
  opacity: 0.7;
}
.about-photo {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  z-index: 1;
  border: 3px solid var(--bg);
}

/* ─── Project cards ───────────────────────────────────────────── */
.projects-grid {
  display: grid;
  gap: 20px;
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: start;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s ease, background 0.3s ease, transform 0.3s var(--ease), box-shadow 0.3s ease;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: var(--gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.project-card:hover {
  border-color: var(--border-hover);
  background: var(--surface-2);
  transform: translateY(-3px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4), 0 0 40px rgba(56, 189, 248, 0.06);
}
.project-card:hover::before { opacity: 1; }

.project-card.featured {
  grid-template-columns: 1fr;
}

.project-body { display: flex; flex-direction: column; gap: 12px; }

.project-number {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  margin-bottom: 2px;
}

.project-title {
  font-size: 19px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.project-desc {
  font-size: 14.5px;
  color: var(--text-subtle);
  line-height: 1.75;
  max-width: 640px;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

.tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  padding: 3px 9px;
  border-radius: 5px;
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.15);
  color: var(--accent-1);
  letter-spacing: 0.02em;
}

.project-links {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  flex-shrink: 0;
  flex-wrap: wrap;
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-subtle);
  border: 1px solid var(--border);
  padding: 7px 14px;
  border-radius: var(--radius);
  transition: all 0.2s ease;
  white-space: nowrap;
}
.project-link:hover {
  color: var(--accent-1);
  border-color: rgba(56, 189, 248, 0.4);
  background: rgba(56, 189, 248, 0.06);
}
.project-link svg { flex-shrink: 0; }

.project-note {
  font-size: 11.5px;
  color: var(--text-muted);
  font-style: italic;
  margin-top: 6px;
}
.project-note a { color: var(--text-muted); text-decoration: underline; text-decoration-color: var(--text-muted); }
.project-note a:hover { color: var(--text-subtle); }

/* ─── Publications ────────────────────────────────────────────── */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.pub-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
  padding: 28px 0;
  border-bottom: 1px solid var(--border);
  transition: all 0.2s ease;
}
.pub-item:first-child { border-top: 1px solid var(--border); }

.pub-year {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.pub-title {
  font-size: 15.5px;
  font-weight: 500;
  color: var(--text);
  line-height: 1.55;
  margin-bottom: 8px;
  transition: color 0.2s ease;
}
.pub-item:hover .pub-title { color: var(--accent-1); }

.pub-venue {
  font-size: 13px;
  color: var(--text-muted);
}

.pub-read-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: var(--radius);
  white-space: nowrap;
  flex-shrink: 0;
  transition: all 0.2s ease;
}
.pub-read-link:hover {
  color: var(--accent-1);
  border-color: rgba(56, 189, 248, 0.4);
  background: rgba(56, 189, 248, 0.06);
}

/* ─── Resume ──────────────────────────────────────────────────── */
.resume-hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
  position: relative;
  overflow: hidden;
  margin-bottom: 64px;
}
.resume-hero-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: var(--gradient);
}

.resume-hero-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--accent-1);
  text-transform: uppercase;
  margin-bottom: 10px;
}

.resume-hero-text {
  font-size: 22px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.resume-hero-sub {
  font-size: 14px;
  color: var(--text-subtle);
}

.resume-areas {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
  margin-bottom: 64px;
}

.resume-area-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.2s ease;
}
.resume-area-card:hover { border-color: rgba(129, 140, 248, 0.3); }

.resume-area-icon {
  font-size: 20px;
  margin-bottom: 12px;
}

.resume-area-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.resume-area-desc {
  font-size: 13px;
  color: var(--text-subtle);
  line-height: 1.65;
}

/* ─── Contact ─────────────────────────────────────────────────── */
.contact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px;
  max-width: 600px;
  position: relative;
  overflow: hidden;
}
.contact-card::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 1px;
  background: var(--gradient);
}

.contact-card p {
  color: var(--text-subtle);
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 32px;
}

.contact-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-subtle);
  border: 1px solid var(--border);
  padding: 10px 20px;
  border-radius: var(--radius);
  transition: all 0.2s var(--ease);
}
.contact-link:hover {
  border-color: var(--border-hover);
  color: var(--accent-1);
  background: rgba(56, 189, 248, 0.06);
  transform: translateY(-1px);
}

/* ─── Footer ──────────────────────────────────────────────────── */
.footer {
  padding: 36px 0;
  position: relative;
}
.footer::before {
  content: '';
  position: absolute;
  top: 0; left: 5%; right: 5%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer p {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

.footer-links {
  display: flex;
  gap: 24px;
}
.footer-links a {
  font-size: 12px;
  color: var(--text-muted);
  transition: color 0.2s ease;
}
.footer-links a:hover { color: var(--text-subtle); }

/* ─── Animations ──────────────────────────────────────────────── */
@keyframes gradient-shift {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@keyframes orb-drift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33%  { transform: translate(30px, -20px) scale(1.05); }
  66%  { transform: translate(-20px, 15px) scale(0.97); }
}

@keyframes bob {
  0%, 100% { transform: translateX(-50%) translateY(0); opacity: 0.5; }
  50%  { transform: translateX(-50%) translateY(6px); opacity: 0.9; }
}

.fade-in {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.65s var(--ease), transform 0.65s var(--ease);
  will-change: opacity, transform;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
  will-change: auto;
}
.delay-1 { transition-delay: 0.08s; }
.delay-2 { transition-delay: 0.16s; }
.delay-3 { transition-delay: 0.24s; }
.delay-4 { transition-delay: 0.32s; }

/* ─── Responsive ──────────────────────────────────────────────── */
@media (max-width: 700px) {
  .menu-toggle { display: flex; }

  .nav-links {
    position: fixed;
    inset: 0;
    background: rgba(8, 11, 16, 0.97);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 36px;
    transform: translateX(100%);
    transition: transform 0.4s var(--ease);
    z-index: 250;
  }
  .nav-links a { font-size: 22px; font-weight: 500; }
  .nav.menu-open .nav-links { transform: translateX(0); }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  .about-photo-wrapper {
    order: -1;
    width: 120px;
    height: 120px;
  }

  .project-card {
    grid-template-columns: 1fr;
  }
  .project-links {
    flex-direction: row;
  }

  .pub-item {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .resume-hero-card {
    flex-direction: column;
    align-items: flex-start;
    padding: 28px;
  }
  .contact-card { padding: 28px; }
  section { padding: 72px 0; }
}