:root {
  --navy-950: #050b16;
  --navy-900: #0a1628;
  --navy-800: #102039;
  --navy-700: #163052;
  --navy-600: #1e3f66;
  --navy-500: #2a5280;
  --sky: #7eb6d9;
  --sky-soft: #a8cce4;
  --gold: #d4b56a;
  --text: #e8eef6;
  --text-dim: #9db0c5;
  --line: rgba(126, 182, 217, 0.18);
  --panel: rgba(16, 32, 57, 0.72);
  --panel-solid: #122744;
  --shadow: 0 28px 70px rgba(0, 0, 0, 0.35);
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Manrope", system-ui, sans-serif;
  --container: 1140px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--text);
  background:
    radial-gradient(900px 480px at 12% -8%, rgba(42, 82, 128, 0.45), transparent 60%),
    radial-gradient(700px 420px at 92% 8%, rgba(126, 182, 217, 0.12), transparent 55%),
    linear-gradient(180deg, var(--navy-900) 0%, var(--navy-950) 55%, #07101d 100%);
  line-height: 1.65;
}

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

a {
  color: var(--sky-soft);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

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

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 22, 40, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}

.nav-shell {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  flex-wrap: wrap;
  gap: 0.65rem 1rem;
  min-height: 4.25rem;
}

.nav-shell .navbar-toggler {
  margin-left: auto;
}

.nav-shell .navbar-collapse {
  flex-basis: 100%;
}

@media (min-width: 992px) {
  .nav-shell .navbar-collapse {
    flex-basis: auto;
    flex-grow: 1;
  }

  .nav-shell .navbar-toggler {
    margin-left: 0;
  }
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  text-decoration: none;
  color: var(--text);
  flex-shrink: 0;
}

.brand img {
  width: 46px;
  height: 46px;
  object-fit: cover;
  border-radius: 50%;
  border: 2px solid rgba(212, 181, 106, 0.55);
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  line-height: 1.15;
}

.brand-tag {
  display: block;
  margin-top: 0.15rem;
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.lang-switch {
  display: inline-flex;
  flex-shrink: 0;
  margin-left: 0.75rem;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
}

.lang-switch button {
  border: 0;
  background: transparent;
  color: var(--text-dim);
  font: inherit;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  padding: 0.4rem 0.55rem;
  cursor: pointer;
}

.lang-switch button.is-active {
  background: var(--sky);
  color: var(--navy-950);
  font-weight: 700;
}

.navbar-dark .navbar-toggler {
  border-color: var(--line);
  padding: 0.35rem 0.5rem;
}

.navbar-dark .navbar-toggler-icon {
  width: 1.2em;
  height: 1.2em;
}

.navbar-nav .nav-link {
  color: var(--text-dim) !important;
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.5rem 0.75rem !important;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.is-active {
  color: var(--text) !important;
}

.btn-yk {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.8rem 1.3rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none !important;
  border: 1px solid transparent;
  transition: transform 0.25s ease, background 0.25s ease, border-color 0.25s ease, color 0.25s ease;
}

.btn-yk-primary {
  background: var(--sky);
  color: var(--navy-950) !important;
  border-color: var(--sky);
}

.btn-yk-primary:hover {
  background: #96c8e6;
  color: var(--navy-950) !important;
  transform: translateY(-2px);
}

.btn-yk-ghost {
  background: transparent;
  color: var(--text) !important;
  border-color: rgba(168, 204, 228, 0.35);
}

.btn-yk-ghost:hover {
  border-color: var(--sky);
  color: var(--sky-soft) !important;
  transform: translateY(-2px);
}

/* Hero */
.hero {
  position: relative;
  min-height: min(92vh, 880px);
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background:
    linear-gradient(105deg, rgba(5, 11, 22, 0.92) 0%, rgba(10, 22, 40, 0.72) 48%, rgba(10, 22, 40, 0.28) 100%),
    url("../img/hero-banner.jpg") center center / cover no-repeat;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 100px;
  background: linear-gradient(to top, var(--navy-950), transparent);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  padding: clamp(5rem, 14vh, 8.5rem) 0 4.5rem;
  max-width: 680px;
}

.hero-kicker {
  display: inline-block;
  margin-bottom: 1rem;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sky);
}

.hero-brand {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-size: clamp(2.7rem, 6.4vw, 4.5rem);
  line-height: 1.02;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: #fff;
}

.hero-lead {
  margin: 0 0 1.75rem;
  max-width: 34rem;
  font-size: clamp(1.05rem, 2vw, 1.2rem);
  color: rgba(232, 238, 246, 0.88);
}

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

.hero-brand,
.hero-lead,
.hero-cta,
.hero-kicker {
  animation: rise 0.85s ease both;
}

.hero-kicker { animation-delay: 0.05s; }
.hero-brand { animation-delay: 0.12s; }
.hero-lead { animation-delay: 0.24s; }
.hero-cta { animation-delay: 0.36s; }

@keyframes rise {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: none; }
}

/* Sections */
.section {
  padding: clamp(3.5rem, 7vw, 5.75rem) 0;
}

.section-band {
  background: linear-gradient(180deg, rgba(16, 32, 57, 0.55), rgba(8, 16, 30, 0.35));
  border-block: 1px solid var(--line);
}

.section-head {
  max-width: 38rem;
  margin-bottom: 2.25rem;
}

.section-head h2,
.page-hero h1 {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: #fff;
}

.section-head h2 {
  font-size: clamp(1.85rem, 3.4vw, 2.55rem);
}

.section-head p,
.page-hero p {
  margin: 0;
  color: var(--text-dim);
  font-size: 1.05rem;
}

.page-hero {
  padding: 3.75rem 0 1.25rem;
  background:
    linear-gradient(180deg, rgba(30, 63, 102, 0.28), transparent),
    radial-gradient(600px 220px at 80% 0%, rgba(126, 182, 217, 0.12), transparent 70%);
  border-bottom: 1px solid var(--line);
}

.page-hero h1 {
  font-size: clamp(2.1rem, 4vw, 3.1rem);
}

.section-link {
  display: inline-block;
  margin-top: 1.75rem;
  font-weight: 600;
}

/* Panels */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 1.35rem 1.4rem;
}

.panel-index {
  display: block;
  margin-bottom: 0.65rem;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.interest-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.15rem;
}

.interest-tile h3,
.interest-block h2 {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-size: 1.2rem;
  color: #fff;
}

.interest-tile p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.95rem;
}

.interest-list {
  display: grid;
  gap: 1rem;
}

.interest-block {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem 1.25rem;
  align-items: start;
}

.interest-block ul {
  margin: 0.4rem 0 0;
  padding-left: 1.1rem;
  color: var(--text-dim);
}

.interest-block li + li {
  margin-top: 0.25rem;
}

/* Metrics */
.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.metric-value {
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 4vw, 2.9rem);
  line-height: 1;
  color: var(--sky);
  margin-bottom: 0.4rem;
}

.metric-label {
  color: var(--text-dim);
  font-size: 0.9rem;
}

/* Reviews */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.15rem;
}

.review-quote {
  margin: 0;
}

.review-quote p {
  margin: 0 0 0.9rem;
  font-family: var(--font-display);
  font-size: 1.12rem;
  line-height: 1.45;
  color: #fff;
}

.review-quote footer {
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* About */
.about-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.3fr;
  gap: 2rem;
  align-items: start;
}

.about-photo {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
}

.about-photo img {
  width: 100%;
  max-height: 560px;
  object-fit: cover;
  object-position: top center;
}

.about-photo::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(5, 11, 22, 0.45), transparent 40%);
  pointer-events: none;
}

.bio-text {
  font-size: 1.05rem;
  color: var(--text-dim);
}

.lang-note {
  display: inline-block;
  margin-top: 1rem;
  color: var(--sky-soft);
  font-weight: 600;
}

.timeline-title {
  margin: 2.5rem 0 1rem;
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: #fff;
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 2px solid rgba(212, 181, 106, 0.45);
}

.timeline li {
  position: relative;
  padding: 0 0 1.35rem 1.3rem;
  display: grid;
  gap: 0.15rem;
}

.timeline li::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 0.35rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(10, 22, 40, 0.9);
}

.timeline-year {
  font-weight: 700;
  color: var(--sky-soft);
}

.timeline-text {
  color: var(--text-dim);
}

/* Academic */
.nav-tabs-yk {
  border-bottom: 1px solid var(--line) !important;
  gap: 0.2rem;
  flex-wrap: wrap;
}

.nav-tabs-yk .nav-link {
  border: 0 !important;
  border-radius: 0 !important;
  border-bottom: 2px solid transparent !important;
  background: transparent !important;
  color: var(--text-dim) !important;
  padding: 0.75rem 0.9rem;
}

.nav-tabs-yk .nav-link.active {
  color: #fff !important;
  border-bottom-color: var(--sky) !important;
}

.pub-list {
  list-style: none;
  margin: 0.5rem 0 0;
  padding: 0;
}

.pub-list li {
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--line);
  color: var(--text-dim);
  font-size: 0.95rem;
}

.pub-list .num {
  color: var(--gold);
  font-weight: 700;
  margin-right: 0.35rem;
}

.id-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  margin-top: 1rem;
}

.id-title {
  margin: 2.25rem 0 0;
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: #fff;
}

.note-muted {
  margin-top: 1.25rem;
  color: var(--text-dim);
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 1.5rem;
}

.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.contact-list li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--line);
}

.contact-list strong {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--sky);
}

.contact-list span,
.contact-list a {
  color: var(--text);
}

.map-wrap {
  border: 1px solid var(--line);
  overflow: hidden;
  background: var(--panel-solid);
  min-height: 340px;
}

.map-wrap iframe {
  width: 100%;
  height: 100%;
  min-height: 340px;
  border: 0;
  filter: grayscale(0.35) saturate(0.85) brightness(0.85);
}

/* Footer */
.site-footer {
  margin-top: 2rem;
  padding: 2.5rem 0 2rem;
  border-top: 1px solid var(--line);
  background: rgba(5, 11, 22, 0.75);
  color: var(--text-dim);
  font-size: 0.9rem;
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1.25rem;
}

.footer-brand {
  font-family: var(--font-display);
  color: #fff;
  font-size: 1.15rem;
  margin-bottom: 0.35rem;
}

/* Motion */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.65s ease, transform 0.65s ease;
  transition-delay: var(--d, 0ms);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

@media (max-width: 991.98px) {
  .interest-grid,
  .metrics,
  .reviews-grid,
  .about-layout,
  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero {
    background-position: center center;
  }
}

@media (max-width: 767.98px) {
  .interest-grid,
  .metrics,
  .reviews-grid,
  .about-layout,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .brand-tag {
    display: none;
  }

  .hero {
    min-height: 78vh;
    background:
      linear-gradient(180deg, rgba(5, 11, 22, 0.45) 0%, rgba(5, 11, 22, 0.88) 52%, rgba(5, 11, 22, 0.96) 100%),
      url("../img/hero-banner.jpg") center 30% / cover no-repeat;
  }

  .hero-inner {
    max-width: none;
    padding-bottom: 3.25rem;
  }

  .lang-switch {
    margin-left: 0.5rem;
  }

  .interest-block {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}