/* === Tokens === */
:root {
  --c-bg: #0a0a0c;
  --c-surface: #111114;
  --c-border: #1e1e24;
  --c-text: #e4e2df;
  --c-muted: #7a7873;
  --c-accent: #c8ff64;
  --c-accent-dim: rgba(200, 255, 100, .08);
  --c-link: #c8ff64;

  --f-heading: 'Space Grotesk', system-ui, sans-serif;
  --f-body: 'Newsreader', Georgia, serif;

  --space: clamp(1.25rem, 5vw, 2.5rem);
  --max-w: 720px;
  --radius: 8px;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--f-body);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }
a { color: var(--c-link); text-decoration: none; transition: opacity .2s; }
a:hover { opacity: .8; }

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

/* === Nav === */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem var(--space);
  background: rgba(10, 10, 12, .85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
}

.nav-name {
  font-family: var(--f-heading);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--c-text);
  letter-spacing: -.02em;
}

.nav-links { display: flex; gap: 1.75rem; }
.nav-links a {
  font-family: var(--f-heading);
  font-size: .82rem;
  font-weight: 500;
  color: var(--c-muted);
  letter-spacing: .03em;
  transition: color .2s;
}
.nav-links a:hover { color: var(--c-text); opacity: 1; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 28px;
  height: 20px;
  position: relative;
}
.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--c-text);
  border-radius: 1px;
  position: absolute;
  left: 0;
  transition: transform .3s, opacity .3s;
}
.nav-toggle span:first-child { top: 0; }
.nav-toggle span:last-child { bottom: 0; }

.mobile-menu {
  display: none;
  position: fixed;
  top: 56px; left: 0; right: 0;
  z-index: 99;
  background: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  padding: 1.5rem var(--space);
  flex-direction: column;
  gap: 1rem;
}
.mobile-menu a {
  font-family: var(--f-heading);
  font-size: 1rem;
  font-weight: 500;
  color: var(--c-text);
}
.mobile-menu.open { display: flex; }

/* === Hero === */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding: 7rem var(--space) 4rem;
  overflow: hidden;
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--max-w);
}

.hero-intro {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
}

.hero-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  overflow: hidden;
  border: 2px solid var(--c-border);
  flex-shrink: 0;
}
.hero-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-badge {
  font-family: var(--f-heading);
  font-size: .85rem;
  color: var(--c-muted);
}
.hero-badge a {
  color: var(--c-accent);
  font-weight: 600;
}

.hero h1 {
  font-family: var(--f-heading);
  font-size: clamp(2.8rem, 8vw, 5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -.03em;
  margin-bottom: 1.5rem;
}

.hero-lead {
  font-size: clamp(1.05rem, 2.5vw, 1.2rem);
  color: var(--c-muted);
  max-width: 520px;
  line-height: 1.7;
  margin-bottom: 2rem;
}
.hero-lead strong { color: var(--c-text); font-weight: 600; }

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

/* Subtle grid background */
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(200,255,100,.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(200,255,100,.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, black 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 70% 40%, black 20%, transparent 70%);
  pointer-events: none;
}

/* === Link Pills === */
.link-pill {
  display: inline-flex;
  align-items: center;
  padding: .55rem 1.25rem;
  font-family: var(--f-heading);
  font-size: .82rem;
  font-weight: 500;
  letter-spacing: .02em;
  color: var(--c-text);
  border: 1px solid var(--c-border);
  border-radius: 100px;
  transition: border-color .25s, background .25s, color .25s;
}
.link-pill:hover {
  border-color: var(--c-accent);
  background: var(--c-accent-dim);
  color: var(--c-accent);
  opacity: 1;
}

.link-pill--lg {
  padding: .7rem 1.5rem;
  font-size: .9rem;
}

/* === Stats Ribbon === */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem;
  text-align: center;
}
.stat:not(:last-child) {
  border-right: 1px solid var(--c-border);
}

.stat-num {
  font-family: var(--f-heading);
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--c-accent);
  letter-spacing: -.02em;
}
.stat-label {
  font-size: .78rem;
  color: var(--c-muted);
  margin-top: .35rem;
}

/* === Sections === */
.section {
  padding: 5rem var(--space);
  max-width: calc(var(--max-w) + 5rem);
  margin: 0 auto;
}

.section-heading {
  font-family: var(--f-heading);
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: -.02em;
  margin-bottom: 2.5rem;
  padding-bottom: .75rem;
  border-bottom: 2px solid var(--c-accent);
  display: inline-block;
}

/* === Experience Cards === */
.exp-card {
  padding: 2rem 0;
  border-bottom: 1px solid var(--c-border);
}
.exp-card:last-of-type { border-bottom: none; }

.exp-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.5rem;
  margin-bottom: .75rem;
}
.exp-date, .exp-loc {
  font-family: var(--f-heading);
  font-size: .78rem;
  color: var(--c-muted);
  letter-spacing: .02em;
}

.exp-card h3 {
  font-family: var(--f-heading);
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: .75rem;
  letter-spacing: -.01em;
}
.exp-at { color: var(--c-muted); font-weight: 400; }
.exp-card h3 a { color: var(--c-accent); }

.exp-card p {
  color: var(--c-muted);
  line-height: 1.75;
  margin-bottom: 1rem;
}

/* === Tags === */
.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
}
.tag {
  font-family: var(--f-heading);
  font-size: .7rem;
  font-weight: 500;
  padding: .3rem .7rem;
  background: var(--c-accent-dim);
  color: var(--c-accent);
  border-radius: 100px;
  letter-spacing: .02em;
}

/* === Project Grid === */
.project-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.project-card {
  display: block;
  padding: 1.75rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  transition: border-color .3s, transform .25s;
  color: var(--c-text);
}
.project-card:hover {
  border-color: var(--c-accent);
  transform: translateY(-2px);
  opacity: 1;
}

.project-icon {
  width: 36px;
  height: 36px;
  margin-bottom: 1rem;
  color: var(--c-accent);
}
.project-icon svg {
  width: 100%;
  height: 100%;
}

.project-card h3 {
  font-family: var(--f-heading);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: .5rem;
  letter-spacing: -.01em;
}

.project-card p {
  font-size: .92rem;
  color: var(--c-muted);
  line-height: 1.65;
  margin-bottom: 1rem;
}

/* === Open Source === */
.oss-list { display: flex; flex-direction: column; }

.oss-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--c-border);
  color: var(--c-text);
  transition: padding-left .2s;
}
.oss-row:hover { padding-left: .5rem; opacity: 1; }
.oss-row:last-child { border-bottom: none; }

.oss-info h3 {
  font-family: var(--f-heading);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: .25rem;
}
.oss-info p {
  font-size: .85rem;
  color: var(--c-muted);
  line-height: 1.5;
}

.oss-stats {
  flex-shrink: 0;
  font-family: var(--f-heading);
  font-size: .78rem;
  color: var(--c-muted);
  text-align: right;
}

/* === Research === */
.research-card {
  padding: 2rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
}

.research-card h3 {
  font-family: var(--f-heading);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: .4rem;
}

.research-venue {
  font-size: .82rem;
  color: var(--c-accent);
  margin-bottom: 1rem;
  font-style: italic;
}

.research-card > p:not(.research-venue) {
  color: var(--c-muted);
  line-height: 1.75;
  margin-bottom: 1.25rem;
}

.research-links {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

/* === Education === */
.edu-card {
  padding: 2rem;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
}

.edu-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: .4rem;
}

.edu-header h3 {
  font-family: var(--f-heading);
  font-size: 1.2rem;
  font-weight: 600;
  letter-spacing: -.01em;
}

.edu-date {
  font-family: var(--f-heading);
  font-size: .78rem;
  color: var(--c-muted);
}

.edu-degree {
  font-size: .95rem;
  color: var(--c-muted);
  font-style: italic;
  margin-bottom: 1.25rem;
}

.edu-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-bottom: 1.25rem;
}

.edu-item {
  display: flex;
  align-items: center;
  gap: .4rem;
  padding: .4rem .85rem;
  background: var(--c-accent-dim);
  border-radius: 100px;
  font-family: var(--f-heading);
  font-size: .78rem;
  font-weight: 500;
  color: var(--c-accent);
}

.edu-label { letter-spacing: .02em; }

.edu-value {
  font-weight: 700;
}

.edu-note {
  font-size: .9rem;
  color: var(--c-muted);
  line-height: 1.7;
}

/* === Skills === */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.skill-group h4 {
  font-family: var(--f-heading);
  font-size: .85rem;
  font-weight: 600;
  color: var(--c-text);
  margin-bottom: .75rem;
  letter-spacing: .02em;
}

/* === Contact === */
.section--contact {
  text-align: center;
}

.contact-lead {
  color: var(--c-muted);
  font-size: 1.05rem;
  margin-bottom: 2rem;
}

.contact-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .75rem;
  margin-bottom: 1.5rem;
}

.contact-loc {
  font-family: var(--f-heading);
  font-size: .82rem;
  color: var(--c-muted);
}

/* === Footer === */
.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 2rem var(--space);
  border-top: 1px solid var(--c-border);
  font-family: var(--f-heading);
  font-size: .78rem;
  color: var(--c-muted);
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}
.footer-links a { color: var(--c-muted); }
.footer-links a:hover { color: var(--c-text); }

/* === Scroll Reveal === */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .5s ease, transform .5s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* === Responsive === */
@media (max-width: 640px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }

  .stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .stat:nth-child(2) { border-right: none; }

  .hero h1 { font-size: 2.4rem; }

  .hero-intro { flex-direction: column; align-items: flex-start; gap: .75rem; }

  .oss-row { flex-direction: column; align-items: flex-start; }
  .oss-stats { text-align: left; }

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

@media (min-width: 768px) {
  .project-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .skills-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}