/* Wong Air Lab — Academic Research Profile */
/* Hallmark · pre-emit critique: P4 H4 E4 S5 R4 V4 — editorial academic, CV-sourced metrics */

:root {
  --color-primary: #0d3b4c;
  --color-primary-light: #1a5f73;
  --color-accent: #2a9d8f;
  --color-accent-soft: #e8f5f3;
  --color-bg: #f7f9fa;
  --color-surface: #fdfefe;
  --color-text: #1a2332;
  --color-text-muted: #5a6578;
  --color-border: #e2e8f0;
  --color-muted-surface: #f1f5f9;
  --color-on-primary: #fdfefe;
  --color-hero-overlay: rgba(13, 59, 76, 0.04);
  --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
  --max-width: 1100px;
  --nav-height: 4rem;
  --radius: 0.5rem;
  --shadow-sm: 0 1px 3px rgba(13, 59, 76, 0.08);
  --shadow-md: 0 4px 20px rgba(13, 59, 76, 0.1);
  --transition: 0.2s ease;
  --focus-ring: 0 0 0 3px var(--color-accent-soft), 0 0 0 5px var(--color-accent);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  overflow-x: clip;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

h1, h2, h3 {
  font-style: normal;
  overflow-wrap: anywhere;
  min-width: 0;
}

.skip-link {
  position: absolute;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 200;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--transition);
}

.skip-link:focus {
  transform: translateY(0);
  outline: none;
  box-shadow: var(--focus-ring);
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-primary-light);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent);
}

/* ── Layout ── */

.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

/* ── Header & Nav ── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.site-header .container {
  position: relative;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
}

.site-logo {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--color-primary);
  line-height: 1.2;
}

.site-logo:hover {
  color: var(--color-primary);
}

.logo-name {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.logo-sub {
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
  color: var(--color-primary);
  border-radius: var(--radius);
}

.nav-toggle:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.nav-toggle svg {
  display: block;
  width: 1.5rem;
  height: 1.5rem;
}

.site-nav ul {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  display: block;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: background var(--transition), color var(--transition);
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-primary);
  background: var(--color-accent-soft);
}

.site-nav a:focus-visible,
.site-logo:focus-visible,
.btn:focus-visible,
.footer-links a:focus-visible,
.card-link:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

/* ── Hero ── */

.hero {
  background-color: var(--color-primary);
  background-image:
    radial-gradient(circle at 20% 80%, var(--color-hero-overlay) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, var(--color-hero-overlay) 0%, transparent 45%);
  color: var(--color-on-primary);
  padding: 4.5rem 0 4rem;
  border-bottom: 3px solid var(--color-accent);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: center;
}

.hero-eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  opacity: 0.85;
  margin: 0 0 0.75rem;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 600;
  line-height: 1.15;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.hero-title {
  font-size: 1.15rem;
  font-weight: 400;
  opacity: 0.92;
  margin: 0 0 1.25rem;
}

.hero-affiliation {
  font-size: 0.95rem;
  opacity: 0.85;
  margin: 0 0 1.5rem;
  max-width: 36rem;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-block;
  padding: 0.3rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 500;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 2rem;
  backdrop-filter: blur(4px);
}

.hero-avatar {
  width: 10rem;
  height: 10rem;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  border: 3px solid rgba(255, 255, 255, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.9);
  flex-shrink: 0;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: background var(--transition), transform var(--transition);
}

.btn-primary {
  background: var(--color-on-primary);
  color: var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-accent-soft);
  color: var(--color-primary);
}

.btn-primary.btn-solid {
  background: var(--color-primary);
  color: var(--color-on-primary);
}

.btn-primary.btn-solid:hover {
  background: var(--color-primary-light);
  color: var(--color-on-primary);
}

.btn-outline {
  background: transparent;
  color: var(--color-on-primary);
  border: 1.5px solid color-mix(in srgb, var(--color-on-primary) 50%, transparent);
}

.btn-outline:hover {
  background: color-mix(in srgb, var(--color-on-primary) 12%, transparent);
  color: var(--color-on-primary);
}

@media (hover: hover) and (pointer: fine) {
  .btn-primary:hover,
  .btn-primary.btn-solid:hover {
    transform: translateY(-1px);
  }

  .card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
  }
}

@media (pointer: coarse) {
  .btn,
  .site-nav a,
  .nav-toggle {
    min-height: 48px;
    min-width: 48px;
  }
}

/* ── Page Header ── */

.page-header {
  background: var(--color-primary);
  color: var(--color-on-primary);
  padding: 3rem 0 2.5rem;
  border-bottom: 3px solid var(--color-accent);
}

.page-header h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 600;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.page-header p {
  margin: 0;
  opacity: 0.85;
  font-size: 1.05rem;
  max-width: 40rem;
}

/* ── Main Content ── */

main {
  padding: 3rem 0 4rem;
}

.section {
  margin-bottom: 3rem;
}

.section:last-child {
  margin-bottom: 0;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0 0 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.section-intro {
  color: var(--color-text-muted);
  font-size: 1.05rem;
  max-width: 48rem;
  margin: 0 0 2rem;
}

/* ── Cards ── */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
}

.card-icon {
  width: 2.75rem;
  height: 2.75rem;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.card h3 {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0 0 0.5rem;
}

.card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.6;
}

.card-link {
  display: inline-block;
  margin-top: 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--color-accent);
}

.card-link:hover {
  text-decoration: underline;
}

/* ── Timeline / Entries ── */

.entry-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.entry {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
}

.entry-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 0.35rem;
}

.entry-title {
  font-weight: 600;
  color: var(--color-primary);
  margin: 0;
  font-size: 1rem;
}

.entry-date {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.entry-org {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin: 0 0 0.5rem;
}

.entry-desc {
  font-size: 0.9rem;
  margin: 0;
  color: var(--color-text);
}

/* ── Publications ── */

.pub-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.pub-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  content-visibility: auto;
  contain-intrinsic-size: auto 5rem;
}

.pub-item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.65;
}

.pub-item a {
  word-break: break-all;
}

.pub-year {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-accent);
  background: var(--color-accent-soft);
  padding: 0.15rem 0.5rem;
  border-radius: 2rem;
  margin-bottom: 0.5rem;
}

.pub-status {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  background: var(--color-muted-surface);
  padding: 0.15rem 0.5rem;
  border-radius: 2rem;
  margin-bottom: 0.5rem;
  margin-left: 0.35rem;
}

/* ── Research Areas ── */

.research-block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.75rem 2rem;
  margin-bottom: 1.5rem;
}

.research-block h3 {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0 0 0.75rem;
}

.research-block p {
  margin: 0;
  color: var(--color-text);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ── Contact Bar ── */

.contact-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--color-accent-soft);
  border-radius: var(--radius);
  margin-top: 2rem;
}

.section-cta {
  margin-top: 1.25rem;
}

.section-intro--tight {
  margin-bottom: 0;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.contact-item strong {
  color: var(--color-primary);
}

.contact-item a {
  color: var(--color-primary-light);
}

/* ── Two-column layout ── */

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

/* ── Stats row ── */

.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-bottom: 3rem;
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-align: center;
}

.stat-number {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

/* ── Footer ── */

.site-footer {
  background: var(--color-primary);
  color: rgba(255, 255, 255, 0.8);
  padding: 2.5rem 0;
  font-size: 0.875rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.footer-inner a {
  color: rgba(255, 255, 255, 0.9);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-links a {
  text-decoration: none;
  white-space: nowrap;
}

.footer-links a:hover {
  text-decoration: underline;
}

/* ── Responsive ── */

@media (max-width: 480px) {
  .stats-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    display: none;
  }

  .site-nav.open {
    display: block;
  }

  .site-nav ul {
    flex-direction: column;
    padding: 0.5rem;
  }

  .site-nav a {
    padding: 0.75rem 1rem;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-avatar {
    margin: 0 auto;
    order: -1;
    width: 7rem;
    height: 7rem;
    font-size: 2rem;
  }

  .hero-tags,
  .hero-actions {
    justify-content: center;
  }

  .two-col {
    grid-template-columns: 1fr;
  }

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