/* ─────────────────────────────────────────
   BASE
───────────────────────────────────────── */
html {
  /* Fallback dark fill before star-nest canvas initialises */
  background: var(--bg-0);
}

body {
  background: transparent;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.7;
}

/* ─────────────────────────────────────────
   NAV
───────────────────────────────────────── */
#nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  padding: 0 clamp(20px, 5vw, 60px);
  /* always blurred — no hard switch on scroll */
  background: rgba(4, 4, 12, 0.72);
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  box-shadow: 0 1px 0 rgba(0, 212, 255, 0.08), 0 4px 20px rgba(0,0,0,0.25);
  transition: background var(--dur-med) var(--ease-smooth),
              box-shadow var(--dur-med);
}

#nav.scrolled {
  background: rgba(4, 4, 12, 0.90);
  box-shadow: 0 1px 0 rgba(0, 212, 255, 0.12), 0 4px 20px rgba(0,0,0,0.4);
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.12em;
  text-shadow: var(--glow-text);
  margin-right: auto;
}

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

.nav-links a {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  position: relative;
  transition: color var(--dur-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--cyan);
  transition: width var(--dur-med) var(--ease-expo);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--cyan);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Mobile hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}

.nav-hamburger span {
  width: 22px;
  height: 1.5px;
  background: var(--text-secondary);
  transition: all var(--dur-med) var(--ease-smooth);
}

/* ─────────────────────────────────────────
   SECTIONS COMMON
───────────────────────────────────────── */
.section {
  padding: clamp(80px, 10vw, 120px) clamp(20px, 5vw, 60px);
  max-width: var(--max-w);
  margin: 0 auto;
}

.section-full {
  padding: clamp(80px, 10vw, 120px) clamp(20px, 5vw, 60px);
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--cyan);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  margin-bottom: 12px;
  opacity: 0;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  color: #ffffff;
  line-height: 1.2;
  clip-path: inset(0 100% 0 0);
  margin-bottom: 48px;
  text-shadow: 0 0 30px rgba(0,212,255,0.25);
}

/* ─────────────────────────────────────────
   HERO
───────────────────────────────────────── */
#hero {
  position: relative;
  height: 100vh;
  min-height: 620px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

#hero-canvas {
  /* Fixed so the star-nest stays visible across all sections */
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 20px;
}

.hero-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--cyan);
  border: 1px solid rgba(0,212,255,0.45);
  padding: 7px 20px;
  border-radius: 100px;
  margin-bottom: 32px;
  opacity: 0;
  background: rgba(0,212,255,0.08);
  backdrop-filter: blur(6px);
  box-shadow: 0 0 16px rgba(0,212,255,0.18);
}

.hero-name-en {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7.5vw, 6rem);
  font-weight: 900;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #ffffff;
  text-shadow: 0 2px 6px rgba(0,0,0,0.85);
  line-height: 1.05;
  min-height: 1.2em;
}

.hero-name-zh {
  font-family: var(--font-body);
  font-size: clamp(1.2rem, 2.8vw, 1.75rem);
  font-weight: 400;
  letter-spacing: 0.7em;
  color: rgba(220, 235, 255, 0.92);
  margin-top: 14px;
  margin-bottom: 28px;
  text-shadow: 0 0 28px rgba(0,212,255,0.45), 0 1px 4px rgba(0,0,0,0.6);
  opacity: 0;
}

.hero-subtitle {
  font-family: var(--font-mono);
  font-size: clamp(0.9rem, 2vw, 1.1rem);
  color: rgba(180, 210, 255, 0.88);
  letter-spacing: 0.12em;
  margin-bottom: 48px;
  min-height: 1.5em;
  opacity: 0;
  text-shadow: 0 0 16px rgba(0,212,255,0.3);
}

.hero-subtitle .cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--cyan);
  margin-left: 2px;
  vertical-align: middle;
  animation: cursorBlink 1s step-end infinite;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #fff;
  padding: 15px 38px;
  border-radius: 6px;
  position: relative;
  overflow: hidden;
  opacity: 0;
  background: linear-gradient(135deg, rgba(0,212,255,0.25) 0%, rgba(123,47,255,0.20) 100%);
  border: 1px solid rgba(0,212,255,0.7);
  box-shadow: 0 0 20px rgba(0,212,255,0.20), inset 0 1px 0 rgba(255,255,255,0.1);
  backdrop-filter: blur(8px);
  transition: background var(--dur-med), box-shadow var(--dur-med), transform var(--dur-fast);
}

.hero-cta:hover {
  background: linear-gradient(135deg, rgba(0,212,255,0.38) 0%, rgba(123,47,255,0.30) 100%);
  box-shadow: var(--glow-cyan), 0 8px 24px rgba(0,0,0,0.4);
  transform: translateY(-2px);
}

.hero-scroll {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  opacity: 0;
  animation: scrollBounce 2s ease-in-out 3s infinite;
}

.hero-scroll svg {
  width: 16px;
  height: 16px;
  stroke: var(--cyan);
}

/* ─────────────────────────────────────────
   ABOUT
───────────────────────────────────────── */
/* ── content-panel: unified background for about + portfolio + contact ── */
#content-panel {
  background: rgba(8, 8, 18, 0.88);
  backdrop-filter: blur(16px) saturate(1.3);
  -webkit-backdrop-filter: blur(16px) saturate(1.3);
}

#about {
  /* background handled by #content-panel */
}

#about .inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: clamp(80px, 10vw, 120px) clamp(20px, 5vw, 60px);
}

/* Stats: horizontal row of cards */
.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 52px;
}

.stat-item {
  background: var(--bg-card);
  border: var(--border);
  border-radius: var(--radius);
  border-left: 3px solid var(--cyan);
  padding: 24px 28px;
  opacity: 0;
  transform: translateY(16px);
}

.stat-number {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--cyan);
  line-height: 1;
  text-shadow: var(--glow-text);
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 6px;
}

/* Bio */
.about-bio {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.85;
  margin-bottom: 44px;
  max-width: 860px;
  opacity: 0;
}

.about-bio strong {
  color: var(--text-primary);
}

.bio-cyan {
  color: var(--cyan);
  text-shadow: var(--glow-text);
  font-weight: 700;
}

/* Skills 2×2 grid */
.skills-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px 52px;
}

.skills-group {
  min-width: 0;
}

.skills-title {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 14px;
  opacity: 0;
}

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

.skill-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 5px 12px;
  border-radius: 4px;
  border: 1px solid rgba(0, 212, 255, 0.2);
  color: var(--text-secondary);
  background: var(--cyan-dim);
  opacity: 0;
  transform: translateY(10px) scale(0.9);
  transition: color var(--dur-fast), border-color var(--dur-fast), background var(--dur-fast);
}

.skill-tag:hover {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(0, 212, 255, 0.1);
}

.skill-tag--highlight {
  color: var(--cyan);
  border-color: rgba(0, 212, 255, 0.6);
  background: rgba(0, 212, 255, 0.12);
  box-shadow: 0 0 10px rgba(0, 212, 255, 0.2);
}

/* ─────────────────────────────────────────
   PORTFOLIO
───────────────────────────────────────── */
#portfolio {
  /* background handled by #content-panel */
}

#portfolio .inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: clamp(80px, 10vw, 120px) clamp(20px, 5vw, 60px);
}

.filter-bar {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 48px;
  opacity: 0;
}

.filter-tab {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  padding: 7px 18px;
  border-radius: 100px;
  border: 1px solid rgba(255,255,255,0.08);
  background: transparent;
  cursor: pointer;
  transition: all var(--dur-fast);
}

.filter-tab:hover,
.filter-tab.active {
  color: var(--cyan);
  border-color: var(--cyan);
  background: var(--cyan-dim);
}

.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--gap);
}

/* ─────────────────────────────────────────
   CONTACT
───────────────────────────────────────── */
#contact {
  /* background handled by #content-panel */
  text-align: center;
}

#contact .inner {
  max-width: 700px;
  margin: 0 auto;
  padding: clamp(80px, 10vw, 120px) clamp(20px, 5vw, 60px);
}

.contact-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 48px;
  opacity: 0;
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  padding: 12px 24px;
  border: var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
  opacity: 0;
  transform: translateY(20px);
  transition: color var(--dur-fast), border-color var(--dur-fast),
              background var(--dur-fast), box-shadow var(--dur-med),
              transform var(--dur-fast);
}

.contact-link svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  flex-shrink: 0;
  transition: transform var(--dur-med) var(--ease-expo);
}

.contact-link:hover {
  color: var(--cyan);
  border-color: var(--cyan);
  background: var(--cyan-dim);
  box-shadow: var(--glow-cyan);
  transform: translateY(-4px);
}

.contact-link:hover svg {
  transform: rotate(12deg);
}

/* ─────────────────────────────────────────
   FOOTER
───────────────────────────────────────── */
footer {
  background: rgba(4, 4, 10, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  text-align: center;
  padding: 28px;
  border-top: 1px solid rgba(255,255,255,0.04);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  letter-spacing: 0.1em;
}

footer span {
  color: var(--cyan);
}

#admin-entry {
  color: transparent;
  text-decoration: none;
  font-size: 0.6rem;
  margin-left: 12px;
  opacity: 0.08;
  transition: opacity 0.4s, color 0.4s;
  user-select: none;
}
#admin-entry:hover {
  opacity: 0.5;
  color: var(--text-muted);
}

/* ─────────────────────────────────────────
   RESPONSIVE
───────────────────────────────────────── */
@media (max-width: 900px) {
  .about-stats {
    grid-template-columns: 1fr 1fr;
  }

  .skills-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .nav-links {
    display: none;
  }

  .nav-hamburger {
    display: flex;
  }
}

@media (max-width: 640px) {
  .hero-name-en {
    letter-spacing: 0.02em;
  }

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