/* Wei Wang Academic Site — custom layer on Tailwind CDN */
:root {
  --accent: #d4a017;
  --accent-soft: rgba(212, 160, 23, 0.15);
  --navy: #0b1220;
  --slate: #1e293b;
  --ink: #0f172a;
  --muted: #64748b;
  --paper: #f8fafc;
  --card: #ffffff;
  --border: #e2e8f0;
  --hero-grad: linear-gradient(135deg, #0b1220 0%, #1e3a5f 45%, #0f2744 100%);
  --shadow: 0 10px 40px -12px rgba(15, 23, 42, 0.18);
  --radius: 1rem;
  --font-sans: "Noto Sans SC", "Inter", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Serif 4", Georgia, serif;
}

html.dark {
  --accent: #e8b84a;
  --accent-soft: rgba(232, 184, 74, 0.18);
  --navy: #020617;
  --slate: #0f172a;
  --ink: #e2e8f0;
  --muted: #94a3b8;
  --paper: #020617;
  --card: #0f172a;
  --border: #1e293b;
  --hero-grad: linear-gradient(135deg, #020617 0%, #0f172a 50%, #132337 100%);
  --shadow: 0 10px 40px -12px rgba(0, 0, 0, 0.55);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.7;
  transition: background .25s, color .25s;
}

h1, h2, h3, .serif { font-family: var(--font-serif); }

/* Nav */
.site-nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom: 1px solid var(--border);
}
.site-nav .inner {
  max-width: 1100px; margin: 0 auto;
  padding: .85rem 1.25rem;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.brand {
  font-weight: 700; letter-spacing: .02em;
  color: var(--ink); text-decoration: none;
  display: flex; align-items: baseline; gap: .5rem;
}
.brand .en { font-size: .78rem; color: var(--muted); font-weight: 500; font-family: var(--font-sans); }
.nav-links {
  display: flex; flex-wrap: wrap; gap: .15rem .85rem;
  list-style: none; margin: 0; padding: 0;
}
.nav-links a {
  text-decoration: none; color: var(--muted); font-size: .88rem;
  transition: color .15s;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); }
.nav-actions { display: flex; align-items: center; gap: .5rem; }
.icon-btn {
  border: 1px solid var(--border); background: var(--card);
  color: var(--ink); border-radius: .65rem;
  width: 2.2rem; height: 2.2rem;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer; transition: border-color .15s, background .15s;
}
.icon-btn:hover { border-color: var(--accent); }
.menu-toggle { display: none; }

@media (max-width: 860px) {
  .menu-toggle { display: inline-flex; }
  .nav-links {
    display: none; position: absolute; left: 0; right: 0; top: 100%;
    flex-direction: column; background: var(--card);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.25rem; gap: .65rem;
  }
  .nav-links.open { display: flex; }
}

/* Hero */
.hero {
  background: var(--hero-grad);
  color: #f1f5f9;
  position: relative; overflow: hidden;
}
.hero::before { display: none; } /* vignette handled by canvas + .hero-overlay */
.crystal-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
  z-index: 0;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background:
    linear-gradient(90deg, rgba(11,18,32,.45) 0%, rgba(11,18,32,.18) 48%, transparent 72%),
    linear-gradient(180deg, rgba(11,18,32,.25) 0%, transparent 35%, rgba(11,18,32,.35) 100%);
}
.hero .inner { z-index: 2; }
.hero .inner {
  max-width: 1100px; margin: 0 auto;
  padding: 5.5rem 1.25rem 4.5rem;
  position: relative; display: grid;
  grid-template-columns: 1.4fr 1fr; gap: 2.5rem; align-items: center;
}
@media (max-width: 800px) {
  .hero .inner { grid-template-columns: 1fr; padding-top: 3.5rem; }
}
.hero-badge {
  display: inline-flex; align-items: center; gap: .4rem;
  font-size: .78rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--accent); background: var(--accent-soft);
  border: 1px solid rgba(212,160,23,.35);
  padding: .35rem .75rem; border-radius: 999px; margin-bottom: 1.1rem;
}
.hero h1 {
  margin: 0 0 .35rem; font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 700; letter-spacing: .04em; line-height: 1.2;
}
.hero .subtitle {
  font-size: 1.15rem; color: #cbd5e1; margin: 0 0 1.25rem;
  font-family: var(--font-sans); font-weight: 400;
}
.hero .meta {
  color: #94a3b8; font-size: .95rem; margin-bottom: 1.5rem;
}
.hero .meta strong { color: #e2e8f0; font-weight: 500; }
.hero-cta { display: flex; flex-wrap: wrap; gap: .75rem; }
.btn {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .7rem 1.2rem; border-radius: .7rem;
  font-size: .92rem; font-weight: 560; text-decoration: none;
  border: 1px solid transparent; cursor: pointer; transition: .15s;
}
.btn-primary {
  background: var(--accent); color: #0b1220;
}
.btn-primary:hover { filter: brightness(1.08); }
.btn-ghost {
  background: transparent; color: #e2e8f0;
  border-color: rgba(226,232,240,.28);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.hero-card {
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  backdrop-filter: blur(8px);
}
.hero-card h3 {
  margin: 0 0 .85rem; font-size: 1rem; color: var(--accent);
  font-family: var(--font-sans); font-weight: 600; letter-spacing: .04em;
}
.hero-card ul { margin: 0; padding: 0; list-style: none; }
.hero-card li {
  padding: .45rem 0; border-bottom: 1px solid rgba(255,255,255,.08);
  font-size: .9rem; color: #cbd5e1;
}
.hero-card li:last-child { border-bottom: none; }
.hero-card .tag {
  display: inline-block; font-size: .72rem; color: var(--accent);
  background: var(--accent-soft); padding: .1rem .45rem; border-radius: .35rem;
  margin-right: .35rem;
}

/* Sections */
.section {
  max-width: 1100px; margin: 0 auto;
  padding: 3.75rem 1.25rem;
}
.section-head {
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 1rem; margin-bottom: 1.75rem; flex-wrap: wrap;
}
.section-head h2 {
  margin: 0; font-size: 1.75rem; letter-spacing: .06em;
  position: relative; padding-bottom: .55rem;
}
.section-head h2::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 0; height: 3px; background: var(--accent); border-radius: 2px;
  transition: width .7s ease .15s;
}
.section-head .hint { color: var(--muted); font-size: .88rem; }

.card-grid {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.25rem 1.35rem;
  box-shadow: var(--shadow);
  transition: transform .15s, border-color .15s;
}
.card:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.card h3 { margin: 0 0 .5rem; font-size: 1.05rem; }
.card p, .card li { color: var(--muted); font-size: .92rem; margin: 0; }
.prose { color: var(--muted); font-size: 1.02rem; max-width: 68ch; }
.prose strong { color: var(--ink); }

/* Timeline */
.timeline { position: relative; padding-left: 1.5rem; }
.timeline::before {
  content: ""; position: absolute; left: .35rem; top: .3rem; bottom: .3rem;
  width: 2px; background: linear-gradient(to bottom, var(--accent), var(--border));
}
.tl-item { position: relative; padding: 0 0 1.6rem 1.1rem; }
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before {
  content: ""; position: absolute; left: -1.28rem; top: .45rem;
  width: .7rem; height: .7rem; border-radius: 50%;
  background: var(--accent); border: 2px solid var(--paper);
  box-shadow: 0 0 0 2px var(--accent-soft);
}
.tl-date {
  font-size: .8rem; color: var(--accent); font-weight: 600;
  letter-spacing: .03em; margin-bottom: .2rem;
}
.tl-title { font-weight: 650; margin: 0 0 .2rem; font-size: 1.02rem; }
.tl-desc { color: var(--muted); font-size: .9rem; margin: 0; }

/* Education cards */
.edu-list { display: grid; gap: 1rem; }
.edu-item {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.2rem 1.35rem;
  display: grid; grid-template-columns: 8.5rem 1fr; gap: 1rem;
}
@media (max-width: 600px) { .edu-item { grid-template-columns: 1fr; } }
.edu-years { color: var(--accent); font-weight: 650; font-size: .9rem; }
.edu-degree { font-weight: 650; margin: 0 0 .25rem; }
.edu-school { color: var(--muted); font-size: .92rem; margin: 0 0 .35rem; }
.edu-thesis { font-size: .88rem; color: var(--muted); margin: 0; }
.edu-thesis em { color: var(--ink); font-style: normal; }

/* Publications */
.pub-controls {
  display: flex; flex-wrap: wrap; gap: .5rem; align-items: center;
  margin-bottom: 1.25rem;
}
.chip {
  border: 1px solid var(--border); background: var(--card);
  color: var(--muted); border-radius: 999px;
  padding: .35rem .85rem; font-size: .82rem; cursor: pointer;
  transition: .15s;
}
.chip:hover, .chip.active {
  background: var(--accent-soft); border-color: var(--accent); color: var(--accent);
}
.pub-list { display: flex; flex-direction: column; gap: .85rem; }
.pub-item {
  background: var(--card); border: 1px solid var(--border);
  border-radius: .85rem; padding: 1rem 1.15rem;
  display: grid; grid-template-columns: 3.2rem 1fr auto; gap: .85rem;
  align-items: start;
}
@media (max-width: 640px) {
  .pub-item { grid-template-columns: 1fr; }
  .pub-year-badge { width: fit-content; }
}
.pub-year-badge {
  background: var(--accent-soft); color: var(--accent);
  font-weight: 700; font-size: .85rem; text-align: center;
  padding: .35rem .4rem; border-radius: .5rem;
}
.pub-title {
  margin: 0 0 .35rem; font-size: .98rem; font-weight: 600;
  color: var(--ink); line-height: 1.45;
}
.pub-meta { font-size: .86rem; color: var(--muted); margin: 0; }
.pub-meta .venue { color: var(--ink); font-style: italic; }
.pub-flags { display: flex; flex-wrap: wrap; gap: .35rem; margin-top: .45rem; }
.flag {
  font-size: .72rem; padding: .12rem .45rem; border-radius: .35rem;
  background: var(--accent-soft); color: var(--accent); font-weight: 600;
}
.flag.note { background: color-mix(in srgb, #38bdf8 18%, transparent); color: #0284c7; }
html.dark .flag.note { color: #7dd3fc; }
.flag.cites { background: color-mix(in srgb, #a78bfa 18%, transparent); color: #7c3aed; }
html.dark .flag.cites { color: #c4b5fd; }
.pub-link {
  font-size: .8rem; color: var(--accent); text-decoration: none;
  white-space: nowrap; padding-top: .2rem;
}
.pub-link:hover { text-decoration: underline; }
.pub-legend {
  font-size: .82rem; color: var(--muted); margin-top: 1rem;
  padding-top: .85rem; border-top: 1px dashed var(--border);
}
.collab-banner {
  background: linear-gradient(90deg, var(--accent-soft), transparent);
  border-left: 3px solid var(--accent);
  padding: .75rem 1rem; border-radius: 0 .65rem .65rem 0;
  margin: 1.5rem 0 .85rem; font-size: .92rem; font-weight: 600;
}

/* Patents / projects */
.table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); }
table.data {
  width: 100%; border-collapse: collapse; background: var(--card);
  font-size: .9rem;
}
table.data th, table.data td {
  text-align: left; padding: .75rem 1rem;
  border-bottom: 1px solid var(--border);
}
table.data th {
  background: color-mix(in srgb, var(--slate) 8%, var(--card));
  font-weight: 650; font-size: .82rem; color: var(--muted);
  letter-spacing: .04em;
}
table.data tr:last-child td { border-bottom: none; }
table.data tr:hover td { background: color-mix(in srgb, var(--accent) 6%, transparent); }
.badge-type {
  display: inline-block; font-size: .72rem; font-weight: 650;
  padding: .15rem .5rem; border-radius: .35rem;
}
.badge-type.inv { background: color-mix(in srgb, #38bdf8 18%, transparent); color: #0369a1; }
.badge-type.util { background: color-mix(in srgb, #34d399 18%, transparent); color: #047857; }
html.dark .badge-type.inv { color: #7dd3fc; }
html.dark .badge-type.util { color: #6ee7b7; }

.skill-cloud { display: flex; flex-wrap: wrap; gap: .5rem; }
.skill-pill {
  background: var(--card); border: 1px solid var(--border);
  padding: .45rem .85rem; border-radius: 999px; font-size: .86rem;
  color: var(--ink);
}

/* Contact */
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem;
}
.contact-item a { color: var(--accent); text-decoration: none; }
.contact-item a:hover { text-decoration: underline; }
.contact-label { font-size: .78rem; color: var(--muted); letter-spacing: .05em; text-transform: uppercase; margin-bottom: .25rem; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 1.25rem; text-align: center;
  color: var(--muted); font-size: .85rem;
}
.site-footer a { color: var(--accent); text-decoration: none; }

/* Band */
.band {
  background: color-mix(in srgb, var(--slate) 6%, var(--paper));
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.loading { color: var(--muted); font-size: .9rem; padding: 1rem 0; }

/* —— Language toggle —— */
.lang-toggle {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border);
  background: var(--card);
  border-radius: .65rem;
  overflow: hidden;
  height: 2.2rem;
}
.lang-toggle button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: .75rem;
  font-weight: 650;
  letter-spacing: .04em;
  padding: 0 .65rem;
  height: 100%;
  cursor: pointer;
  transition: background .15s, color .15s;
}
.lang-toggle button.active {
  background: var(--accent-soft);
  color: var(--accent);
}
.lang-toggle button:hover:not(.active) {
  color: var(--ink);
}

/* —— Nav scrolled state —— */
.site-nav {
  transition: box-shadow .25s, background .25s, border-color .25s;
}
.site-nav.scrolled {
  box-shadow: 0 8px 28px -16px rgba(15, 23, 42, 0.35);
  background: color-mix(in srgb, var(--paper) 90%, transparent);
}
html.dark .site-nav.scrolled {
  box-shadow: 0 8px 28px -12px rgba(0, 0, 0, 0.65);
}

/* —— Legacy orbs hidden (replaced by crystal canvas) —— */
.hero-orbs, .orb { display: none !important; }

/* —— Featured / Selected publications —— */
.featured-lead {
  color: var(--muted);
  font-size: .95rem;
  max-width: 68ch;
  margin: -.5rem 0 1rem;
}
.data-updated {
  font-size: .82rem;
  color: var(--muted);
  margin: 0 0 1rem;
  letter-spacing: .02em;
}
.featured-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.featured-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem 1.25rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: .35rem;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
  position: relative;
  overflow: hidden;
}
.featured-card::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--accent), #38bdf8);
}
.featured-card:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
  box-shadow: 0 16px 36px -16px rgba(15, 23, 42, 0.28);
}
.featured-year {
  font-size: .78rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: .04em;
}
.featured-title {
  margin: 0;
  font-size: 1rem;
  font-weight: 650;
  line-height: 1.4;
  color: var(--ink);
  font-family: var(--font-serif);
}
.featured-authors {
  margin: 0;
  font-size: .84rem;
  color: var(--muted);
}
.featured-venue {
  margin: 0;
  font-size: .84rem;
  color: var(--ink);
}
.featured-venue em { font-style: italic; color: var(--ink); }
.featured-actions { margin-top: auto; padding-top: .65rem; }
.featured-cta {
  font-size: .82rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
}
.featured-cta:hover { text-decoration: underline; }
.featured-cta.muted, .pub-link.muted {
  color: var(--muted);
  font-weight: 500;
  cursor: default;
}

/* —— Scroll reveal —— */
.reveal, .reveal-hero {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .65s ease, transform .65s ease;
}
.reveal.is-visible, .reveal-hero.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* —— Section title underline grow —— */
.section-head.reveal.is-visible h2::after,
.section-head:not(.reveal) h2::after {
  width: 2.5rem;
}

/* —— Card / pub hover polish —— */
.card {
  transition: transform .22s ease, border-color .22s ease, box-shadow .22s ease;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px -18px rgba(15, 23, 42, 0.28), 0 0 0 1px color-mix(in srgb, var(--accent) 25%, transparent);
}
html.dark .card:hover {
  box-shadow: 0 16px 40px -14px rgba(0, 0, 0, 0.55), 0 0 0 1px color-mix(in srgb, var(--accent) 30%, transparent);
}
.pub-item {
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.pub-item:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
  box-shadow: 0 12px 28px -16px rgba(15, 23, 42, 0.25);
}
.skill-pill {
  transition: border-color .15s, transform .15s, box-shadow .15s;
}
.skill-pill:hover {
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  transform: translateY(-1px);
}

/* —— Reduced motion —— */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .reveal-hero {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
  .section-head h2::after { width: 2.5rem !important; transition: none !important; }
  .card, .pub-item, .skill-pill, .featured-card { transition: none !important; }
}