/* ==============================
   Jian Li — CV Website
   Aesthetic: Editorial · Dark
   ============================== */

:root {
  --bg:         #0c0c0e;
  --bg-alt:     #111114;
  --bg-dark:    #08080a;
  --surface:    #18181c;
  --border:     #2a2a30;
  --border-lt:  #1e1e24;
  --text:       #e8e6e1;
  --text-muted: #8a8a8f;
  --text-dim:   #5a5a60;
  --accent:     #c9a55a;
  --accent-dim: rgba(201,165,90,0.12);
  --accent-glow:rgba(201,165,90,0.25);
  --white:      #ffffff;
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'Manrope', -apple-system, sans-serif;
  --font-mono:    'JetBrains Mono', monospace;
  --max-w: 1200px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* Grain overlay */
.grain {
  position: fixed; inset: 0; z-index: 9999;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px;
}

/* ── Navigation ── */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 100;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: rgba(12,12,14,0.8);
  border-bottom: 1px solid var(--border-lt);
  transition: transform 0.4s var(--ease);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 2rem;
  height: 64px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--accent);
  letter-spacing: 0.04em;
}
.nav-links { display: flex; gap: 2rem; }
.nav-links a {
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color 0.3s;
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute; bottom: -4px; left: 0;
  width: 0; height: 1px;
  background: var(--accent);
  transition: width 0.3s var(--ease);
}
.nav-links a:hover { color: var(--accent); }
.nav-links a:hover::after { width: 100%; }

/* Mobile toggle */
.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(--text);
  position: absolute; left: 0;
  transition: all 0.3s var(--ease);
}
.nav-toggle span:first-child { top: 0; }
.nav-toggle span:last-child { bottom: 0; }
.nav-toggle.active span:first-child { top: 50%; transform: rotate(45deg) translateY(-50%); }
.nav-toggle.active span:last-child { bottom: 50%; transform: rotate(-45deg) translateY(50%); }

.mobile-menu {
  display: none;
  position: fixed; inset: 0; z-index: 99;
  background: rgba(12,12,14,0.96);
  flex-direction: column;
  align-items: center; justify-content: center;
  gap: 2rem;
  opacity: 0; pointer-events: none;
  transition: opacity 0.4s var(--ease);
}
.mobile-menu.open { opacity: 1; pointer-events: all; }
.mobile-link {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--text-muted);
  transition: color 0.3s;
}
.mobile-link:hover { color: var(--accent); }

/* ── Hero ── */
.hero {
  min-height: 100vh;
  display: flex; flex-direction: column;
  justify-content: center;
  padding: 120px 2rem 60px;
  position: relative;
  background:
    radial-gradient(ellipse 60% 50% at 70% 40%, rgba(201,165,90,0.06) 0%, transparent 70%),
    var(--bg);
}
.hero-grid {
  max-width: var(--max-w);
  margin: 0 auto; width: 100%;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 4rem;
  align-items: center;
}
.hero-tag {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.2rem;
}
.hero-name {
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 7vw, 5.5rem);
  line-height: 1.05;
  color: var(--white);
  margin-bottom: 1.4rem;
}
.hero-sub {
  font-size: 1.12rem;
  color: var(--text-muted);
  max-width: 520px;
  line-height: 1.75;
  margin-bottom: 2.2rem;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center;
  padding: 0.8rem 1.8rem;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  border-radius: 6px;
  transition: all 0.3s var(--ease);
  cursor: pointer;
}
.btn-primary {
  background: var(--accent);
  color: var(--bg);
  border: 1px solid var(--accent);
}
.btn-primary:hover {
  background: transparent;
  color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim);
}
.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  border-color: var(--text-muted);
  color: var(--text);
}

/* Hero card */
.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
}
.hero-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent);
}
.hero-card-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.6rem;
}
.hero-card-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--white);
  margin-bottom: 0.3rem;
}
.hero-card-sub {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}
.hero-card-detail {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* Stats */
.hero-stats {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--border-lt);
  border-radius: 10px;
  padding: 1.2rem 1rem;
  text-align: center;
}
.stat-number {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--accent);
  display: inline;
}
.stat-suffix {
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--accent);
}
.stat-label {
  display: block;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-top: 0.3rem;
}

/* Scroll hint */
.scroll-hint {
  position: absolute; bottom: 2rem; left: 50%;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center;
  gap: 0.6rem;
  color: var(--text-dim);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.scroll-line {
  width: 1px; height: 40px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.6); }
  50% { opacity: 1; transform: scaleY(1); }
}

/* ── Sections ── */
.section {
  padding: 100px 2rem;
}
.section-alt { background: var(--bg-alt); }
.section-dark {
  background: var(--bg-dark);
  border-top: 1px solid var(--border-lt);
}
.section-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}
.section-header {
  display: flex; align-items: baseline; gap: 1rem;
  margin-bottom: 3.5rem;
}
.section-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  letter-spacing: 0.08em;
}
.section-title {
  font-family: var(--font-display);
  font-size: 2.6rem;
  color: var(--white);
}

/* ── About ── */
.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 4rem;
  align-items: start;
}
.about-lead {
  font-size: 1.2rem;
  color: var(--text);
  line-height: 1.8;
  margin-bottom: 1.4rem;
}
.about-text p {
  color: var(--text-muted);
  margin-bottom: 1.2rem;
  font-size: 0.95rem;
}
.about-text strong { color: var(--text); font-weight: 600; }

.about-highlights { display: flex; flex-direction: column; gap: 1.4rem; }
.highlight {
  display: flex; gap: 1rem; align-items: flex-start;
  padding: 1.2rem 1.4rem;
  background: var(--surface);
  border: 1px solid var(--border-lt);
  border-radius: 10px;
  transition: border-color 0.3s;
}
.highlight:hover { border-color: var(--accent); }
.highlight-icon { font-size: 1.4rem; flex-shrink: 0; margin-top: 0.1rem; }
.highlight-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--white);
  margin-bottom: 0.2rem;
}
.highlight-desc {
  font-size: 0.82rem;
  color: var(--text-dim);
  line-height: 1.5;
}

/* ── Timeline ── */
.timeline { position: relative; }
.timeline::before {
  content: '';
  position: absolute;
  top: 0; bottom: 0; left: 140px;
  width: 1px;
  background: var(--border);
}
.timeline-item {
  display: flex; gap: 3rem;
  padding-bottom: 3rem;
  position: relative;
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: '';
  position: absolute; left: 136px; top: 8px;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--bg-alt);
  border: 2px solid var(--accent);
  z-index: 1;
}

.timeline-date {
  width: 110px; flex-shrink: 0;
  text-align: right;
  padding-top: 0.1rem;
}
.timeline-year {
  display: block;
  font-family: var(--font-display);
  font-size: 1.3rem;
  color: var(--accent);
}
.timeline-range {
  font-size: 0.72rem;
  color: var(--text-dim);
  letter-spacing: 0.02em;
}

.timeline-content {
  flex: 1;
  padding-left: 1.5rem;
}
.timeline-company {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.3rem;
}
.timeline-role {
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: var(--white);
  margin-bottom: 1rem;
}
.timeline-list {
  list-style: none;
  display: flex; flex-direction: column; gap: 0.5rem;
  margin-bottom: 1rem;
}
.timeline-list li {
  font-size: 0.88rem;
  color: var(--text-muted);
  padding-left: 1.2rem;
  position: relative;
}
.timeline-list li::before {
  content: '';
  position: absolute; left: 0; top: 0.6em;
  width: 4px; height: 4px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.6;
}
.timeline-list em {
  font-style: italic;
  color: var(--text);
}
.timeline-tags { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.timeline-tags span {
  font-size: 0.7rem;
  padding: 0.25rem 0.7rem;
  border-radius: 20px;
  border: 1px solid var(--border);
  color: var(--text-dim);
  letter-spacing: 0.03em;
}

/* ── Education ── */
.edu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.2rem;
}
.edu-card {
  background: var(--surface);
  border: 1px solid var(--border-lt);
  border-radius: 12px;
  padding: 1.8rem;
  transition: border-color 0.3s, transform 0.3s var(--ease);
}
.edu-card:hover {
  border-color: var(--border);
  transform: translateY(-2px);
}
.edu-card-featured {
  border-color: var(--accent);
  background: linear-gradient(135deg, var(--surface) 0%, rgba(201,165,90,0.05) 100%);
  grid-column: span 2;
}
.edu-period {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.6rem;
}
.edu-degree {
  font-family: var(--font-display);
  font-size: 1.25rem;
  color: var(--white);
  margin-bottom: 0.3rem;
}
.edu-field {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}
.edu-school {
  font-size: 0.8rem;
  color: var(--text-dim);
}
.edu-note {
  margin-top: 0.8rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--border-lt);
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 500;
}

/* ── Skills ── */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}
.skills-group {
  background: var(--surface);
  border: 1px solid var(--border-lt);
  border-radius: 12px;
  padding: 1.8rem;
}
.skills-group-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.2rem;
}
.skill-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.skill-tag {
  font-size: 0.82rem;
  padding: 0.4rem 1rem;
  border-radius: 6px;
  background: var(--accent-dim);
  color: var(--text);
  font-weight: 500;
  transition: background 0.3s;
}
.skill-tag:hover { background: var(--accent-glow); }

/* Language bars */
.lang-bars { display: flex; flex-direction: column; gap: 1rem; }
.lang-bar {}
.lang-info {
  display: flex; justify-content: space-between;
  margin-bottom: 0.4rem;
  font-size: 0.85rem;
}
.lang-info span:first-child { color: var(--text); font-weight: 500; }
.lang-level { color: var(--text-dim); font-size: 0.78rem; }
.lang-track {
  height: 4px; border-radius: 4px;
  background: var(--border);
  overflow: hidden;
}
.lang-fill {
  height: 100%; width: 0;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--accent), rgba(201,165,90,0.5));
  transition: width 1.2s var(--ease);
}

/* Certifications */
.cert-list { display: flex; flex-direction: column; gap: 0.8rem; }
.cert-item {
  display: flex; gap: 1rem; align-items: baseline;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.cert-year {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  flex-shrink: 0;
}

/* ── Contact ── */
.contact-inner { text-align: center; }
.contact-inner .section-header { justify-content: center; }
.contact-text {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto 2.5rem;
}
.contact-cards {
  display: flex; gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}
.contact-card {
  background: var(--surface);
  border: 1px solid var(--border-lt);
  border-radius: 12px;
  padding: 2rem 2.5rem;
  text-align: center;
  transition: border-color 0.3s, transform 0.3s var(--ease);
  min-width: 220px;
}
.contact-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
}
.contact-card-icon { font-size: 1.6rem; margin-bottom: 0.6rem; }
.contact-card-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.3rem;
}
.contact-card-value {
  font-size: 0.92rem;
  color: var(--accent);
  font-weight: 500;
}
.contact-refs {
  font-size: 0.82rem;
  color: var(--text-dim);
  font-style: italic;
}

/* ── Footer ── */
.footer {
  border-top: 1px solid var(--border-lt);
  padding: 1.5rem 2rem;
}
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex; justify-content: center; gap: 0.5rem;
  font-size: 0.78rem;
  color: var(--text-dim);
}
.footer-sep { opacity: 0.4; }

/* ── Animations ── */
.anim-up {
  opacity: 0;
  transform: translateY(28px);
  animation: animUp 0.8s var(--ease) forwards;
}
.d1 { animation-delay: 0.15s; }
.d2 { animation-delay: 0.3s; }
.d3 { animation-delay: 0.45s; }
.d4 { animation-delay: 0.7s; }

@keyframes animUp {
  to { opacity: 1; transform: translateY(0); }
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .about-grid { grid-template-columns: 1fr; gap: 2rem; }
  .skills-grid { grid-template-columns: 1fr; }
  .edu-card-featured { grid-column: span 1; }

  .timeline::before { left: 20px; }
  .timeline-item { flex-direction: column; gap: 0.5rem; padding-left: 44px; }
  .timeline-item::before { left: 16px; }
  .timeline-date { width: auto; text-align: left; }
  .timeline-content { padding-left: 0; }
}

@media (max-width: 640px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .mobile-menu { display: flex; }

  .hero { padding: 100px 1.2rem 60px; }
  .hero-name { font-size: 2.8rem; }
  .hero-stats { grid-template-columns: repeat(3, 1fr); gap: 0.6rem; }
  .stat { padding: 0.8rem 0.5rem; }
  .stat-number { font-size: 1.5rem; }

  .section { padding: 60px 1.2rem; }
  .section-title { font-size: 2rem; }
  .section-header { margin-bottom: 2.5rem; }

  .edu-grid { grid-template-columns: 1fr; }
  .contact-cards { flex-direction: column; align-items: center; }
  .contact-card { width: 100%; }
  .scroll-hint { display: none; }
}