:root {
  --sea-deep: #0b3d5c;
  --sea-mid: #1a6b8a;
  --sea-light: #4db8c9;
  --sea-foam: #a8e6f0;
  --sand: #f0f8fa;
  --text: #0a2a3a;
  --text-muted: #3d5a6b;
  --white: #ffffff;
  --shadow: rgba(11, 61, 92, 0.15);
  --radius: 12px;
  --transition: 0.3s ease;
  --max-width: 1100px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: linear-gradient(180deg, #c8ecf5 0%, var(--sand) 40%, #e8f4f8 100%);
  min-height: 100vh;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 1000;
  padding: 0.75rem 1.25rem;
  background: var(--sea-deep);
  color: var(--white);
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 600;
}

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

/* Animated wave background */
.wave-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.wave-bg svg {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 200%;
  height: 40%;
  min-height: 180px;
  animation: wave-drift 12s ease-in-out infinite;
}

.wave-bg .wave-2 {
  bottom: 5%;
  opacity: 0.6;
  animation-duration: 16s;
  animation-direction: reverse;
}

.wave-bg .wave-3 {
  bottom: 10%;
  opacity: 0.35;
  animation-duration: 20s;
}

@keyframes wave-drift {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(-25%); }
}

/* Header */
.site-header {
  background: linear-gradient(135deg, var(--sea-deep), var(--sea-mid));
  color: var(--white);
  box-shadow: 0 4px 20px var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--white);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.logo:hover,
.logo:focus-visible {
  color: var(--sea-foam);
  outline: 2px solid var(--sea-foam);
  outline-offset: 4px;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 2px solid var(--sea-foam);
  color: var(--white);
  padding: 0.4rem 0.75rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
}

.main-nav a {
  color: var(--sea-foam);
  text-decoration: none;
  padding: 0.35rem 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.main-nav a:hover,
.main-nav a:focus-visible,
.main-nav a[aria-current="page"] {
  color: var(--white);
  border-bottom-color: var(--sea-light);
  outline: none;
}

/* Page layout with side ad slots */
.page-layout {
  display: grid;
  grid-template-columns: 160px minmax(0, var(--max-width)) 160px;
  justify-content: center;
  gap: 1.25rem;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 1rem;
  align-items: start;
}

.page-center {
  min-width: 0;
  width: 100%;
}

.ad-slot {
  position: sticky;
  top: 5.5rem;
  width: 160px;
  justify-self: center;
}

.ad-label {
  display: block;
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 0.5rem;
}

.ad-inner {
  width: 160px;
  min-height: 600px;
  max-height: 600px;
  background: rgba(255, 255, 255, 0.8);
  border: 1px dashed var(--sea-light);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ad-inner:empty::before {
  content: "160 × 600";
  font-size: 0.7rem;
  color: var(--text-muted);
  opacity: 0.55;
  text-align: center;
  padding: 0.5rem;
}

.ad-inner img,
.ad-inner iframe {
  max-width: 100%;
  display: block;
}

/* Main content */
main {
  margin: 0;
  padding: 2rem 0 4rem;
}

h1 {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  color: var(--sea-deep);
  margin-top: 0;
}

h2 {
  font-size: 1.35rem;
  color: var(--sea-mid);
  margin-top: 2rem;
}

h3 {
  font-size: 1.1rem;
  color: var(--sea-mid);
}

/* Cards & sections */
.hero {
  background: var(--white);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: 0 8px 32px var(--shadow);
  margin-bottom: 2rem;
  border-left: 4px solid var(--sea-light);
  animation: fade-up 0.6s ease-out;
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.disclaimer,
.transparency-box {
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--sea-foam);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  color: var(--text-muted);
}

.transparency-box {
  border-left: 4px solid var(--sea-mid);
}

.transparency-box h2 {
  margin-top: 0;
}

/* Photo gallery */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
  margin: 2rem 0;
}

.photo-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 6px 20px var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}

.photo-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px var(--shadow);
}

.photo-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
}

.photo-card figcaption {
  padding: 0.75rem 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Resources list */
.article-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.article-list li {
  margin-bottom: 0.75rem;
}

.article-list a {
  display: block;
  padding: 1rem 1.25rem;
  background: var(--white);
  border-radius: var(--radius);
  color: var(--sea-deep);
  text-decoration: none;
  box-shadow: 0 2px 12px var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}

.article-list a:hover,
.article-list a:focus-visible {
  transform: translateX(4px);
  box-shadow: 0 4px 16px var(--shadow);
  outline: 2px solid var(--sea-light);
}

.article-list .placeholder {
  display: block;
  padding: 1rem 1.25rem;
  background: rgba(255, 255, 255, 0.6);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-style: italic;
  border: 1px dashed var(--sea-foam);
}

/* Contact */
.contact-card {
  background: var(--white);
  padding: 2rem;
  border-radius: var(--radius);
  box-shadow: 0 8px 32px var(--shadow);
  max-width: 480px;
}

.contact-card a {
  color: var(--sea-mid);
  font-weight: 600;
}

.contact-card a:hover,
.contact-card a:focus-visible {
  color: var(--sea-deep);
}

/* Article page */
.article-body {
  background: var(--white);
  padding: 2rem;
  border-radius: var(--radius);
  box-shadow: 0 8px 32px var(--shadow);
}

.article-body .back-link {
  display: inline-block;
  margin-bottom: 1.5rem;
  color: var(--sea-mid);
}

.article-body .article-note {
  margin-top: 0;
  color: var(--text-muted);
}

.article-body ul {
  padding-left: 1.25rem;
  margin: 0.75rem 0 1.25rem;
}

.article-body li {
  margin-bottom: 0.35rem;
}

.article-body h3 {
  margin-top: 1.25rem;
  margin-bottom: 0.35rem;
  font-size: 1rem;
}

.article-faq {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--sea-foam);
}

.article-related {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--sea-foam);
}

.article-related h2 {
  margin-top: 0;
  font-size: 1.15rem;
}

.article-related ul {
  list-style: none;
  padding: 0;
  margin: 0.75rem 0 0;
}

.article-related li {
  margin-bottom: 0.5rem;
}

.article-related a {
  color: var(--sea-mid);
  font-weight: 600;
}

.article-related a:hover,
.article-related a:focus-visible {
  color: var(--sea-deep);
}

.latest-articles h3 {
  margin-top: 1.25rem;
  margin-bottom: 0.35rem;
}

.latest-articles h3:first-of-type {
  margin-top: 0.5rem;
}

/* 404 page */
.error-hero {
  background: var(--white);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  box-shadow: 0 8px 32px var(--shadow);
  text-align: center;
  border-left: 4px solid var(--sea-light);
  margin-bottom: 1.5rem;
}

.error-code {
  font-size: clamp(4rem, 18vw, 7rem);
  font-weight: 800;
  line-height: 1;
  margin: 0 0 0.5rem;
  background: linear-gradient(135deg, var(--sea-deep), var(--sea-light));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: -0.04em;
}

.error-hero h1 {
  margin-bottom: 0.75rem;
}

.error-hero > p {
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
  color: var(--text-muted);
}

.error-actions {
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--sea-foam);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  margin-bottom: 1.5rem;
}

.error-actions h2 {
  margin-top: 0;
  font-size: 1.15rem;
}

.error-links {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.75rem;
}

.error-links a {
  display: block;
  padding: 0.85rem 1rem;
  background: var(--white);
  border-radius: var(--radius);
  color: var(--sea-deep);
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 2px 12px var(--shadow);
  border: 1px solid var(--sea-foam);
  transition: transform var(--transition), box-shadow var(--transition);
}

.error-links a:hover,
.error-links a:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--shadow);
  color: var(--sea-mid);
  outline: 2px solid var(--sea-light);
  outline-offset: 2px;
}

.error-articles {
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--sea-foam);
}

.error-articles h2 {
  margin-top: 0;
  font-size: 1rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.error-articles ul {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0;
}

.error-articles li {
  margin-bottom: 0.4rem;
}

.error-articles a {
  color: var(--sea-mid);
  font-weight: 600;
}

.error-articles a:hover,
.error-articles a:focus-visible {
  color: var(--sea-deep);
}

/* Footer */
.site-footer {
  background: linear-gradient(135deg, var(--sea-deep), var(--sea-mid));
  color: var(--sea-foam);
  text-align: center;
  padding: 1.5rem;
  margin-top: auto;
  font-size: 0.9rem;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem 1.25rem;
  margin-bottom: 0.75rem;
}

.footer-nav a {
  color: var(--sea-foam);
  text-decoration: none;
  font-weight: 600;
}

.footer-nav a:hover,
.footer-nav a:focus-visible {
  color: var(--white);
  text-decoration: underline;
  outline: none;
}

.site-footer p {
  margin: 0.25rem 0;
}

/* Responsive */
@media (max-width: 1280px) {
  .page-layout {
    grid-template-columns: 1fr;
    padding: 0 1.5rem;
  }

  .ad-slot {
    display: none;
  }

  main {
    padding-left: 0;
    padding-right: 0;
  }
}

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

  .main-nav {
    width: 100%;
    display: none;
  }

  .main-nav.is-open {
    display: block;
  }

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

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

  .wave-bg svg,
  .photo-card {
    animation: none;
    transition: none;
  }
}