:root {
  --ink: #101820;
  --slate: #263746;
  --cyan: #2bb3c0;
  --lime: #a3c95a;
  --amber: #f4a340;
  --paper: #f5f3ee;
  --white: #ffffff;
  --text: #26313a;
  --muted: #66737e;
  --border: #d7dde1;
  --surface: #eef2f3;
  --radius: 20px;
  --shadow: 0 24px 60px rgba(16, 24, 32, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--paper);
  color: var(--text);
  line-height: 1.65;
}

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

a {
  color: inherit;
}

button,
input {
  font: inherit;
}

.container {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

/* Accessibility */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 1000;
  padding: 10px 14px;
  background: var(--ink);
  color: #ffffff;
  transform: translateY(-150%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 3px;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(245, 243, 238, 0.94);
  border-bottom: 1px solid rgba(16, 24, 32, 0.08);
  backdrop-filter: blur(14px);
}

.nav-shell {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand img {
  width: 235px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.site-nav a {
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 700;
  transition: color 0.2s ease;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--cyan);
}

.menu-button {
  display: none;
  border: 0;
  border-radius: 999px;
  background: var(--ink);
  color: #ffffff;
  padding: 10px 16px;
  cursor: pointer;
}

/* Hero Section */
.hero {
  overflow: hidden;
  background:
    radial-gradient(circle at 80% 18%, rgba(43, 179, 192, 0.20), transparent 34%),
    radial-gradient(circle at 62% 82%, rgba(163, 201, 90, 0.18), transparent 30%),
    var(--paper);
}

.hero-grid {
  min-height: 675px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 76px;
  padding-block: 92px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--cyan);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.17em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  color: var(--ink);
  line-height: 1.08;
}

h1 {
  max-width: 850px;
  margin-bottom: 24px;
  font-size: clamp(3rem, 6vw, 5.8rem);
  letter-spacing: -0.055em;
}

h1 em {
  color: var(--lime);
  font-style: normal;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(2.2rem, 4vw, 3.7rem);
  letter-spacing: -0.045em;
}

h3 {
  margin-bottom: 14px;
  font-size: 1.35rem;
}

.lead {
  max-width: 720px;
  color: var(--muted);
  font-size: 1.16rem;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 22px;
  border-radius: 999px;
  background: var(--ink);
  color: #ffffff;
  text-decoration: none;
  font-weight: 800;
  transition: background-color 0.2s ease;
}

.button:hover {
  background: var(--cyan);
}

.text-link {
  text-decoration: none;
  font-weight: 800;
  transition: color 0.2s ease;
}

.text-link:hover {
  color: var(--cyan);
}

.hero-visual {
  position: relative;
  min-height: 460px;
  display: grid;
  place-items: center;
}

.hero-visual img {
  width: min(390px, 80%);
  border-radius: 30px;
  box-shadow: var(--shadow);
}

.chip {
  position: absolute;
  padding: 9px 16px;
  border: 1px solid rgba(16, 24, 32, 0.12);
  border-radius: 999px;
  background: #ffffff;
  box-shadow: 0 10px 30px rgba(16, 24, 32, 0.1);
  font-weight: 800;
}

.chip-a {
  top: 14%;
  left: 0;
}

.chip-b {
  top: 28%;
  right: 0;
}

.chip-c {
  bottom: 26%;
  left: 2%;
}

.chip-d {
  right: 5%;
  bottom: 11%;
}

/* Signal Band */
.signal-band {
  background: var(--ink);
  color: #ffffff;
}

.signal-band-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  font-weight: 750;
}

.signal-band-inner b {
  color: var(--amber);
}

/* Sections General */
.section {
  padding-block: 110px;
}

.section-heading {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: end;
  gap: 60px;
  margin-bottom: 55px;
}

.section-heading > p {
  color: var(--muted);
}

/* Field Cards */
.field-grid,
.method-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.field-card,
.person-card {
  padding: 30px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.68);
}

.field-card {
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.field-card:hover {
  transform: translateY(-5px);
  border-color: var(--cyan);
  box-shadow: var(--shadow);
}

.field-number {
  display: inline-block;
  margin-bottom: 48px;
  color: var(--amber);
  font-weight: 900;
}

.field-card p,
.field-card li,
.person-card p {
  color: var(--muted);
}

.field-card ul {
  margin-bottom: 0;
  padding-left: 20px;
}

/* Method Section */
.method {
  background: var(--ink);
}

.inverse h2,
.inverse p {
  color: #ffffff;
}

.inverse .eyebrow {
  color: #72d8df;
}

.method-grid {
  color: #ffffff;
}

.method-card {
  padding: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.22);
}

.method-card span {
  display: block;
  margin-bottom: 44px;
  color: var(--amber);
  font-weight: 900;
}

.method-card h3 {
  color: #ffffff;
}

.method-card p {
  color: rgba(255, 255, 255, 0.72);
}

/* Academic Perspectives */
.people-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.person-card {
  position: relative;
  overflow: hidden;
  background: #ffffff;
}

.person-card::after {
  content: "";
  position: absolute;
  width: 96px;
  height: 96px;
  right: -38px;
  bottom: -38px;
  border-radius: 50%;
  background: rgba(163, 201, 90, 0.12);
}

.avatar {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  margin-bottom: 24px;
  border-radius: 16px;
  background: var(--ink);
  color: #ffffff;
  font-weight: 900;
}

.specialty {
  margin-bottom: 8px;
  color: var(--amber) !important;
  font-size: 0.78rem;
  font-weight: 850;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.institution {
  font-size: 0.92rem;
  font-weight: 700;
}

.person-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  margin-top: 12px;
}

.person-links a {
  color: var(--cyan);
  text-decoration: none;
  font-weight: 800;
}

.notice {
  margin-top: 30px;
  padding: 22px 25px;
  border-left: 4px solid var(--amber);
  background: #ffffff;
  color: var(--muted);
}

/* Learning Library */
.library {
  background: #ffffff;
}

.search-box {
  display: flex;
  flex-direction: column;
  gap: 8px;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 800;
}

.search-box input {
  min-width: 290px;
  padding: 13px 16px;
  border: 1px solid var(--border);
  border-radius: 999px;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-box input:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(43, 179, 192, 0.13);
}

.resources {
  display: grid;
  gap: 10px;
}

.resources details {
  padding: 21px 24px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  transition: border-color 0.2s ease;
}

.resources details[open] {
  border-color: var(--cyan);
}

.resources summary {
  cursor: pointer;
  color: var(--ink);
  font-weight: 850;
}

.resources details p {
  max-width: 860px;
  margin: 16px 0 0;
  color: var(--muted);
}

.empty-results {
  margin-top: 20px;
  color: var(--muted);
}

/* About Section */
.about-grid {
  display: grid;
  grid-template-columns: 0.65fr 1.35fr;
  align-items: center;
  gap: 80px;
}

.about-mark img {
  width: min(330px, 100%);
  margin-inline: auto;
  border-radius: 30px;
  box-shadow: var(--shadow);
}

/* Footer */
.footer {
  padding-block: 60px;
  background: var(--ink);
  color: rgba(255, 255, 255, 0.72);
}

.footer-grid {
  display: grid;
  gap: 14px;
}

.footer img {
  width: 230px;
  filter: brightness(0) invert(1);
}

/* Back to Top Button */
.back-top {
  position: fixed;
  right: 25px;
  bottom: 25px;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 50%;
  background: var(--amber);
  color: var(--ink);
  font-size: 1.2rem;
  font-weight: 900;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.back-top.visible {
  opacity: 1;
  pointer-events: auto;
}

/* Reveal Animations */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive Media Queries */
@media (max-width: 950px) {
  .menu-button {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 82px;
    right: 20px;
    left: 20px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 20px;
    border-radius: 16px;
    background: #ffffff;
    box-shadow: var(--shadow);
  }

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

  .hero-grid,
  .section-heading,
  .about-grid {
    grid-template-columns: 1fr;
  }

  .field-grid,
  .method-grid,
  .people-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .signal-band-inner {
    flex-wrap: wrap;
    justify-content: center;
    padding-block: 22px;
  }
}

@media (max-width: 650px) {
  .container {
    width: min(100% - 28px, 1180px);
  }

  .brand img {
    width: 188px;
  }

  .hero-grid {
    min-height: auto;
    padding-block: 70px;
    gap: 30px;
  }

  h1 {
    font-size: 3.05rem;
  }

  .hero-actions {
    align-items: flex-start;
    flex-direction: column;
  }

  .field-grid,
  .method-grid,
  .people-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding-block: 75px;
  }

  .hero-visual {
    min-height: 380px;
  }

  .search-box input {
    width: 100%;
    min-width: 0;
  }
}