:root {
  --cyan: #12aeea;
  --teal: #007a9f;
  --navy: #0b0838;
  --navy-2: #101040;
  --aqua: #41c7c7;
  --pale: #d7f2fa;
  --paper: #f7fbfd;
  --white: #ffffff;
  --ink: #121629;
  --muted: #666a73;
  --line: rgba(16, 16, 64, 0.12);
  --shadow: 0 18px 48px rgba(11, 8, 56, 0.13);
  --radius: 18px;
  --container: min(1160px, calc(100vw - 40px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

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

a {
  color: inherit;
  text-decoration: none;
}

img,
svg {
  max-width: 100%;
}

button,
input,
select,
textarea {
  font: inherit;
}

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

.skip-link {
  position: absolute;
  top: -6rem;
  left: 1rem;
  z-index: 1000;
  border-radius: 10px;
  background: var(--navy);
  color: var(--white);
  padding: 0.75rem 1rem;
}

.skip-link:focus {
  top: 1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(18px);
}

.header-inner {
  width: var(--container);
  min-height: 86px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(190px, 0.8fr) minmax(520px, 1.5fr) minmax(300px, 0.8fr);
  align-items: center;
  gap: 1.25rem;
}

.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 0.1rem;
  line-height: 1.1;
}

.brand strong {
  color: var(--navy);
  font-size: 1.12rem;
  letter-spacing: 0;
}

.brand span {
  color: var(--teal);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.2rem;
}

.nav-item {
  position: relative;
}

.nav-link,
.menu-toggle,
.icon-button {
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--navy);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.65rem 0.78rem;
  font-size: 0.92rem;
  font-weight: 800;
}

.nav-link:hover,
.menu-toggle:hover,
.icon-button:hover {
  background: var(--pale);
  color: var(--teal);
}

.dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 260px;
  padding: 0.55rem;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--white);
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: 160ms ease;
}

.nav-item:hover .dropdown,
.nav-item:focus-within .dropdown {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.dropdown a {
  display: block;
  border-radius: 12px;
  padding: 0.72rem 0.85rem;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 750;
}

.dropdown a:hover {
  background: var(--pale);
  color: var(--teal);
}

.header-actions {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 0.65rem;
}

.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--white);
}

.language-switcher {
  display: flex;
  gap: 0.35rem;
  align-items: center;
}

.language-switcher a {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  color: var(--navy);
  padding: 0.45rem 0.62rem;
  font-size: 0.78rem;
  font-weight: 850;
}

.language-switcher a:hover {
  border-color: var(--cyan);
  color: var(--teal);
}

.language-switcher a.active {
  border-color: var(--cyan);
  background: var(--pale);
  color: var(--teal);
}

.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 80% 10%, rgba(18, 174, 234, 0.33), transparent 26rem),
    radial-gradient(circle at 14% 85%, rgba(65, 199, 199, 0.22), transparent 22rem),
    linear-gradient(135deg, var(--navy), var(--navy-2));
  color: var(--white);
}

.hero::before,
.section-dark::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(255, 255, 255, 0.18) 1.1px, transparent 1.1px),
    linear-gradient(120deg, transparent 0 38%, rgba(18, 174, 234, 0.12) 38% 39%, transparent 39% 100%);
  background-size: 26px 26px, 100% 100%;
  opacity: 0.55;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  width: var(--container);
  min-height: 720px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.72fr);
  gap: 3rem;
  align-items: center;
  padding: 5rem 0;
}

.eyebrow {
  color: var(--cyan);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 920px;
  margin-bottom: 1.3rem;
  color: inherit;
  font-size: clamp(3.2rem, 7vw, 6.6rem);
  line-height: 0.94;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 1rem;
  color: var(--navy);
  font-size: clamp(2rem, 4vw, 3.3rem);
  line-height: 1.02;
  letter-spacing: 0;
}

h3 {
  color: var(--navy);
  line-height: 1.16;
}

.hero-lede {
  max-width: 760px;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(1.1rem, 1.8vw, 1.35rem);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1.8rem;
}

.button,
.button-secondary,
.button-dark {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 0.72rem 1.12rem;
  font-weight: 900;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button {
  background: var(--cyan);
  color: var(--navy);
  box-shadow: 0 14px 34px rgba(18, 174, 234, 0.28);
}

.button-secondary {
  border: 1px solid rgba(255, 255, 255, 0.32);
  color: var(--white);
}

.button-dark {
  background: var(--navy);
  color: var(--white);
}

.button:hover,
.button-secondary:hover,
.button-dark:hover {
  transform: translateY(-2px);
}

.hero-photo-card {
  position: relative;
  align-self: stretch;
  min-height: 610px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 32px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.18), rgba(255, 255, 255, 0.06)),
    rgba(255, 255, 255, 0.08);
  box-shadow: 0 28px 80px rgba(0, 0, 0, 0.28);
  overflow: hidden;
}

.hero-photo-card img {
  position: absolute;
  inset: auto 0 0 auto;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 16%;
}

.hero-badge {
  position: absolute;
  left: 1rem;
  right: 1rem;
  bottom: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 20px;
  background: rgba(11, 8, 56, 0.82);
  color: var(--white);
  padding: 1rem;
  backdrop-filter: blur(16px);
}

.hero-badge strong {
  display: block;
  color: var(--cyan);
}

.section {
  padding: 5.5rem 0;
}

.section-tight {
  padding: 3.2rem 0;
}

.container {
  width: var(--container);
  margin: 0 auto;
}

.section-pale {
  background: var(--pale);
}

.section-white {
  background: var(--white);
}

.section-dark {
  position: relative;
  overflow: hidden;
  background: var(--navy);
  color: var(--white);
}

.section-dark > * {
  position: relative;
}

.section-dark h2,
.section-dark h3 {
  color: var(--white);
}

.section-dark p {
  color: rgba(255, 255, 255, 0.76);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 3rem;
  align-items: start;
}

.grid {
  display: grid;
  gap: 1.2rem;
}

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card,
.resource-card,
.stat-card,
.quote-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 12px 36px rgba(11, 8, 56, 0.07);
}

.card {
  padding: 1.35rem;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

.card:hover {
  transform: translateY(-3px);
  border-color: rgba(18, 174, 234, 0.45);
  box-shadow: var(--shadow);
}

.card .label,
.resource-card .label,
.stat-card .label {
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.card p,
.resource-card p,
.stat-card p,
.page-content p,
.page-content li {
  color: var(--muted);
}

.card-link {
  display: inline-flex;
  margin-top: 1rem;
  color: var(--teal);
  font-weight: 900;
}

.stat-card {
  padding: 1.25rem;
}

.stat-value {
  display: block;
  color: var(--navy);
  font-size: 2.4rem;
  font-weight: 950;
  line-height: 1;
}

.stat-citation {
  color: var(--teal);
  font-weight: 900;
  white-space: nowrap;
}

.reference-list {
  display: grid;
  gap: 0.9rem;
  max-width: 960px;
}

.reference-list p {
  margin: 0;
  color: var(--muted);
}

.reference-list a {
  color: var(--teal);
  font-weight: 900;
}

.page-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 88% 20%, rgba(18, 174, 234, 0.25), transparent 22rem),
    linear-gradient(135deg, var(--navy), var(--navy-2));
  color: var(--white);
}

.page-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255, 255, 255, 0.16) 1px, transparent 1px);
  background-size: 24px 24px;
  opacity: 0.52;
}

.page-hero-inner {
  position: relative;
  width: var(--container);
  margin: 0 auto;
  padding: 5rem 0 4rem;
}

.page-hero h1 {
  font-size: clamp(2.7rem, 6vw, 5.2rem);
}

.page-hero p {
  max-width: 820px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 1.16rem;
}

.summary-box {
  max-width: 840px;
  margin-top: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.08);
  padding: 1rem 1.1rem;
  color: rgba(255, 255, 255, 0.84);
}

.breadcrumb {
  margin-bottom: 1.4rem;
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
  font-weight: 750;
}

.breadcrumb a {
  color: var(--cyan);
}

.page-content {
  max-width: 850px;
}

.page-content h2 {
  margin-top: 2.7rem;
}

.page-content h2:first-child {
  margin-top: 0;
}

.page-content ul {
  padding-left: 1.2rem;
}

.callout {
  border-left: 5px solid var(--cyan);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--pale);
  padding: 1.1rem 1.25rem;
}

.compact-disclaimer {
  margin-bottom: 1.2rem;
  padding: 0.85rem 1rem;
}

.compact-disclaimer p {
  margin: 0.25rem 0 0;
}

.teaching-philosophy p {
  margin: 1rem 0 0;
}

.teaching-philosophy strong {
  display: block;
  color: var(--navy);
  font-size: 1.15rem;
  line-height: 1.2;
}

.model-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 1.8rem;
}

.model-filter button {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  color: var(--navy);
  cursor: pointer;
  padding: 0.58rem 0.9rem;
  font-weight: 850;
}

.model-filter button.active {
  border-color: var(--cyan);
  background: var(--cyan);
}

.resource-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 156px;
  gap: 1rem;
  padding: 1.25rem;
}

.resource-card strong {
  color: var(--navy);
}

.qr-box {
  min-height: 156px;
  display: grid;
  place-items: center;
  gap: 0.35rem;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--white);
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 900;
  padding: 0.65rem;
  text-align: center;
}

.qr-box img {
  width: 126px;
  height: 126px;
}

.qr-box:hover {
  border-color: rgba(18, 174, 234, 0.55);
  box-shadow: 0 10px 28px rgba(11, 8, 56, 0.08);
}

.footer {
  background: var(--navy);
  color: var(--white);
}

.footer-inner {
  width: var(--container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(2, minmax(180px, 0.8fr));
  gap: 2rem;
  padding: 3rem 0;
}

.footer a {
  display: inline-flex;
  margin: 0.15rem 0.5rem 0.15rem 0;
  color: rgba(255, 255, 255, 0.76);
}

.footer a:hover {
  color: var(--cyan);
}

.footer p {
  color: rgba(255, 255, 255, 0.7);
}

.social-row {
  display: flex;
  gap: 0.7rem;
  margin-top: 1rem;
}

.footer .social-icon {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin: 0;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 12px;
  color: var(--white);
  background: rgba(255, 255, 255, 0.08);
}

.social-icon svg {
  width: 26px;
  height: 26px;
}

.social-icon rect,
.social-icon circle {
  fill: currentColor;
}

.social-icon text {
  fill: var(--navy);
  font-size: 14px;
  font-weight: 900;
  font-family: Inter, ui-sans-serif, system-ui, sans-serif;
}

.social-icon path {
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.social-scholar circle {
  fill: currentColor;
  opacity: 0.22;
}

.social-scholar path:first-of-type {
  fill: currentColor;
  stroke: none;
  opacity: 0.95;
}

.social-scholar path:last-of-type {
  stroke: var(--navy);
}

.footer .social-icon:hover {
  color: var(--cyan);
  transform: translateY(-2px);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  padding: 1rem 0;
  color: rgba(255, 255, 255, 0.62);
  font-size: 0.9rem;
  text-align: center;
}

.support-banner {
  position: fixed;
  z-index: 200;
}

.support-banner {
  inset: auto 0 0 0;
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 -16px 46px rgba(11, 8, 56, 0.14);
  padding: 1rem;
}

.support-inner {
  width: var(--container);
  margin: 0 auto;
  display: flex;
  gap: 1rem;
  justify-content: space-between;
  align-items: center;
}

.support-inner p {
  margin-bottom: 0;
  color: var(--muted);
}

.hidden {
  display: none !important;
}

@media (max-width: 1180px) {
  .header-inner {
    grid-template-columns: 1fr auto;
    padding: 0.9rem 0;
  }

  .main-nav {
    grid-column: 1 / -1;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 0.3rem;
  }

  .header-actions {
    justify-content: flex-end;
  }
}

@media (max-width: 1500px) and (min-width: 1181px) {
  .header-inner {
    width: min(1320px, calc(100vw - 40px));
    grid-template-columns: minmax(220px, 0.45fr) minmax(0, 1fr);
    gap: 0.8rem 1.25rem;
    padding: 0.85rem 0;
  }

  .main-nav {
    justify-content: flex-end;
  }

  .header-actions {
    grid-column: 1 / -1;
    justify-content: center;
    flex-wrap: wrap;
  }
}

@media (max-width: 840px) {
  :root {
    --container: min(100vw - 28px, 720px);
  }

  .header-inner {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    min-height: unset;
    padding: 0.9rem 0;
  }

  .brand {
    margin-right: auto;
  }

  .menu-toggle {
    display: inline-flex;
  }

  .main-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    overflow: visible;
  }

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

  .nav-link {
    width: 100%;
    justify-content: space-between;
  }

  .dropdown {
    position: static;
    display: block;
    min-width: 100%;
    opacity: 1;
    transform: none;
    pointer-events: auto;
    box-shadow: none;
    margin-bottom: 0.5rem;
  }

  .header-actions {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .language-switcher {
    flex-wrap: wrap;
  }

  .hero-inner,
  .split,
  .footer-inner {
    grid-template-columns: 1fr;
  }

  .hero-inner {
    min-height: unset;
    padding: 4rem 0;
  }

  .hero-photo-card {
    min-height: 520px;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .resource-card {
    grid-template-columns: 1fr;
  }

  .support-inner {
    align-items: stretch;
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  h1 {
    font-size: 3rem;
  }

  .hero-photo-card {
    min-height: 430px;
  }

  .button-row {
    flex-direction: column;
  }

  .button,
  .button-secondary,
  .button-dark {
    width: 100%;
  }
}