:root {
  --blue: #2563eb;
  --blue-dark: #1e40af;
  --light-blue: #3b82f6;
  --blue-soft: #eff6ff;
  --gray-bg: #f0f4f8;
  --card-border: #e2e8f0;
  --text-dark: #1e293b;
  --text-light: #475569;
  --text-muted: #64748b;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  background: var(--gray-bg);
  color: var(--text-dark);
  -webkit-font-smoothing: antialiased;
}

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

body > header {
  position: relative;
  overflow: hidden;
  padding: 4.75rem 1rem 6.75rem;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.18), transparent 30%),
    linear-gradient(135deg, var(--light-blue), var(--blue-dark));
}

body > header h1 {
  max-width: 960px;
  margin: 0 auto;
  font-size: clamp(2.4rem, 7vw, 3.75rem);
  line-height: 1.08;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.wrapper {
  padding: 0 1rem 4rem;
}

main.container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 900px;
  margin-top: -3.5rem;
  padding: clamp(1.5rem, 5vw, 3rem);
  border: 1px solid var(--card-border);
  border-radius: 18px;
  background: white;
  box-shadow: 0 18px 40px rgba(30, 64, 175, 0.12);
}

.back-button {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin: 0 0 1.75rem;
  padding: 0.65rem 1rem;
  border: 1px solid #bfdbfe;
  border-radius: 999px;
  background: var(--blue-soft);
  color: var(--blue-dark);
  font-size: 0.92rem;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  transition: transform 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.back-button:hover {
  transform: translateX(-2px);
  border-color: #93c5fd;
  background: #dbeafe;
  color: var(--blue-dark);
  text-decoration: none;
}

.back-button:focus-visible,
.page-toc summary:focus-visible,
.page-toc a:focus-visible,
.container a:focus-visible,
.site-footer-nav a:focus-visible,
.back-to-top:focus-visible {
  outline: 3px solid #93c5fd;
  outline-offset: 3px;
}

.page-toc {
  margin: 0 0 2rem;
  border: 1px solid #bfdbfe;
  border-radius: 14px;
  background: #f8fbff;
}

.page-toc summary {
  padding: 0.9rem 1rem;
  color: var(--blue-dark);
  font-weight: 600;
  cursor: pointer;
}

.page-toc ol {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.65rem 1.25rem;
  margin: 0;
  padding: 0 1.25rem 1.15rem 2.5rem;
}

.page-toc li {
  padding-left: 0.15rem;
  color: var(--text-muted);
}

.page-toc a {
  color: var(--text-light);
  line-height: 1.4;
  text-decoration: none;
}

.page-toc a:hover {
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

main.container > h2,
main.container > section > h2 {
  scroll-margin-top: 1.5rem;
  margin-top: 2.75rem;
  padding-left: 0.85rem;
  border-left: 4px solid var(--blue);
  color: var(--text-dark);
  font-size: clamp(1.45rem, 4vw, 1.85rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

main.container h3 {
  margin-top: 2rem;
  color: var(--text-dark);
  line-height: 1.35;
}

main.container p,
main.container li {
  line-height: 1.7;
}

main.container p {
  color: var(--text-light);
}

main.container a:not(.back-button):not(.back-to-top) {
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

.image-wrapper,
.media-collage,
.photo-collage,
.photo-grid {
  margin-top: 1.75rem;
  margin-bottom: 2.25rem;
}

.image-wrapper img,
.media-collage img,
.media-collage video,
.photo-collage img,
.photo-grid img,
main.container > video,
main.container iframe {
  max-width: 100%;
  border-radius: 14px;
  box-shadow: 0 8px 24px rgba(30, 41, 59, 0.09);
}

.media-collage video,
main.container > video {
  display: block;
  width: 100%;
  height: auto;
}

main.container iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  height: auto;
}

.caption,
figcaption {
  color: var(--text-muted);
  line-height: 1.5;
}

.callout-box {
  border: 1px solid #bfdbfe;
  border-radius: 14px;
  background: var(--blue-soft);
}

.site-footer-nav {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--card-border);
}

.site-footer-nav__home {
  display: inline-block;
  margin-bottom: 1rem;
  color: var(--text-dark);
  font-size: 1.05rem;
  font-weight: 600;
  text-decoration: none;
}

.site-footer-nav__home:hover {
  color: var(--blue);
}

.site-footer-nav__links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.6rem;
}

.site-footer-nav__links a {
  display: flex;
  align-items: center;
  min-height: 2.7rem;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--card-border);
  border-radius: 10px;
  background: #f8fafc;
  color: var(--text-light);
  font-size: 0.85rem;
  line-height: 1.35;
  text-decoration: none;
  transition: border-color 0.2s ease, background-color 0.2s ease, color 0.2s ease;
}

.site-footer-nav__links a:hover {
  border-color: #bfdbfe;
  background: var(--blue-soft);
  color: var(--blue-dark);
  text-decoration: none;
}

.site-footer-nav__links a[aria-current="page"] {
  border-color: #93c5fd;
  background: #dbeafe;
  color: var(--blue-dark);
  font-weight: 600;
}

.back-to-top {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 10;
  display: grid;
  width: 2.9rem;
  height: 2.9rem;
  place-items: center;
  border: 1px solid #bfdbfe;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 8px 24px rgba(30, 64, 175, 0.18);
  color: var(--blue-dark);
  font-size: 1.2rem;
  font-weight: 600;
  text-decoration: none;
  backdrop-filter: blur(8px);
  transition: transform 0.2s ease, background-color 0.2s ease;
}

.back-to-top:hover {
  transform: translateY(-3px);
  background: white;
  color: var(--blue-dark);
  text-decoration: none;
}

@media (max-width: 700px) {
  body > header {
    padding: 3.75rem 1rem 5.75rem;
  }

  main.container {
    margin-top: -2.75rem;
  }

  .page-toc ol,
  .site-footer-nav__links {
    grid-template-columns: 1fr;
  }

  .back-to-top {
    right: 0.75rem;
    bottom: 0.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .back-button,
  .site-footer-nav__links a,
  .back-to-top {
    transition: none;
  }
}

@media print {
  body > header {
    padding: 2rem 1rem;
  }

  main.container {
    margin-top: 0;
    box-shadow: none;
  }

  .back-button,
  .page-toc,
  .site-footer-nav,
  .back-to-top {
    display: none;
  }
}