/* ─── NAV ─── */
#nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-inline: 2rem;
  background: rgba(8, 8, 8, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: border-color 0.3s;
}

.nav-logo {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--cyan);
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  transition: color 0.2s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s;
}

.nav-links a:hover {
  color: var(--text);
}

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

.nav-links a.active {
  color: var(--text);
}

.nav-links a:focus-visible,
.nav-drawer a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
  border-radius: var(--r-sm);
}

/* Hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.nav-hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text-muted);
  transition: all 0.25s;
}

.nav-hamburger.open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.nav-hamburger.open span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav-hamburger.open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* Mobile drawer */
.nav-drawer {
  display: none;
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  background: rgba(8, 8, 8, 0.97);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 2rem;
  flex-direction: column;
  gap: 1.25rem;
  z-index: 99;
}

.nav-drawer.open {
  display: flex;
}

.nav-drawer a {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.nav-drawer a:hover {
  color: var(--text);
}

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

/* dot grid background */
#hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

/* top glow */
#hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 80%;
  height: 40%;
  background: radial-gradient(ellipse at top, rgba(0, 212, 255, 0.05) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: 100%;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4.5rem;
  align-items: center;
}

.hero-eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--cyan);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 1.2rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.hero-eyebrow::before {
  content: '';
  display: inline-block;
  width: 20px;
  height: 1px;
  background: var(--cyan);
}

.hero-name {
  font-size: clamp(2.8rem, 6vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.05;
  margin-bottom: 0.8rem;
}

.hero-name span {
  color: var(--cyan);
}

.hero-role {
  font-size: 1.02rem;
  color: var(--text-muted);
  font-weight: 400;
  margin-bottom: 2rem;
  line-height: 1.6;
}

.hero-role strong {
  color: var(--text);
  font-weight: 600;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 2.5rem;
}

.hero-cta {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ─── SECTIONS ─── */
section {
  position: relative;
  z-index: 1;
}

#architecture {
  padding: var(--section-pad) 0;
  background: radial-gradient(ellipse 55% 40% at 50% 50%, rgba(139, 92, 246, 0.03) 0%, transparent 70%);
}

#projects {
  padding: var(--section-pad) 0;
}

#stack {
  padding: var(--section-pad) 0;
}

#experience {
  padding: var(--section-pad) 0;
}

#academic {
  padding: var(--section-pad) 0;
  background: radial-gradient(ellipse 50% 50% at 25% 60%, rgba(139, 92, 246, 0.03) 0%, transparent 60%);
}

#contact {
  padding: var(--section-pad) 0 6rem;
}

/* ─── ARCHITECTURE DIAGRAM ─── */
.arch-diagram {
  margin-top: 2rem;
  padding: 2rem;
  background: var(--card);
  border: 1px solid var(--border-light);
  border-radius: var(--r-lg);
  overflow-x: auto;
}

.arch-diagram svg {
  margin-inline: auto;
}

/* ─── GRIDS ─── */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
}

.stack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
}

.academic-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

/* ─── FOOTER ─── */
footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--text-faint);
}

/* ─── RESPONSIVE ─── */
@media (max-width: 1024px) {
  .hero-grid {
    gap: 2.5rem;
  }
}

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .academic-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .nav-hamburger {
    display: flex;
  }

  .container {
    padding-inline: 1.25rem;
  }

  :root {
    --section-pad: 3.5rem;
  }

  footer {
    flex-direction: column;
    gap: 0.4rem;
    text-align: center;
  }
}

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

  .arch-diagram {
    padding: 1rem 0.75rem;
  }
}