/* Structural layout: header, nav, footer, containers, page grid */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-surface) 78%, transparent);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.site-header.is-scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.site-header__bar {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  padding: var(--space-3) 0;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--color-text);
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.site-logo:hover {
  transform: translateY(-1px);
}

.site-logo img {
  height: 38px;
  width: auto;
  filter: drop-shadow(0 2px 8px rgba(110, 131, 255, 0.25));
}

.site-header__contact {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.site-header__contact .contact-label {
  font-size: 0.7rem;
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  display: block;
}

.site-header__contact .contact-email {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-text);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: var(--space-2) var(--space-4);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-brand);
  transform: translateY(-1px);
  box-shadow: var(--glow-brand);
}

.nav-toggle {
  display: none;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--color-text);
  flex-shrink: 0;
}

/* ---------- Main nav ---------- */

.site-nav {
  border-top: 1px solid var(--color-border);
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
  padding: var(--space-2) 0;
  flex-wrap: wrap;
}

.site-nav__list > li {
  position: relative;
}

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-text-muted);
  white-space: nowrap;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--gradient-brand);
  transform: translateX(-50%);
  transition: width var(--transition-base);
}

.site-nav__link:hover,
.site-nav__link[aria-expanded="true"] {
  color: var(--color-text);
}

.site-nav__link:hover::after,
.site-nav__link[aria-expanded="true"]::after {
  width: calc(100% - var(--space-5));
}

.site-nav__caret {
  width: 8px;
  height: 8px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg);
  margin-top: -3px;
  opacity: 0.55;
  transition: transform var(--transition-fast);
}

.site-nav__list > li.is-open .site-nav__caret {
  transform: rotate(-135deg);
  margin-top: 2px;
}

.site-nav__submenu {
  position: absolute;
  /* top sits flush against the trigger (no gap) so there's no hover dead-zone
     between the link and the menu; the visual breathing room above the items
     comes from padding-top instead, which is part of the hoverable box. */
  top: 100%;
  left: 0;
  min-width: 230px;
  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: 10px var(--space-2) var(--space-2);
  list-style: none;
  display: none;
  flex-direction: column;
  z-index: 60;
}

.site-nav__list > li.is-open > .site-nav__submenu {
  display: flex;
  animation: submenu-in 0.2s ease;
}

@keyframes submenu-in {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.site-nav__submenu a {
  display: block;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: background var(--transition-fast), color var(--transition-fast),
    padding-left var(--transition-fast);
}

.site-nav__submenu a:hover {
  background: var(--color-brand-tint);
  color: var(--color-brand-light);
  padding-left: var(--space-4);
}

[data-theme="light"] .site-nav__submenu a:hover {
  color: var(--color-brand-dark);
}

@media (max-width: 880px) {
  .nav-toggle {
    display: flex;
  }

  .site-header__contact .contact-label,
  .site-header__contact .contact-email {
    display: none;
  }

  .site-nav {
    display: none;
  }

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

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
  }

  .site-nav__link {
    width: 100%;
  }

  .site-nav__link::after { display: none; }

  .site-nav__submenu {
    position: static;
    box-shadow: none;
    border: none;
    backdrop-filter: none;
    padding-left: var(--space-4);
    display: none;
  }

  .site-nav__list > li.is-open > .site-nav__submenu {
    display: flex;
  }
}

/* ---------- Hero (PageHeader component) ---------- */

.hero {
  position: relative;
  overflow: hidden;
  background: var(--gradient-mesh), var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-8) 0 var(--space-7);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: var(--grid-overlay);
  background-size: 44px 44px;
  -webkit-mask-image: radial-gradient(ellipse 70% 80% at 50% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 70% 80% at 50% 0%, #000 30%, transparent 75%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-5);
}

.hero__icon {
  flex-shrink: 0;
  width: 88px;
  height: 88px;
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--glow-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3);
  position: relative;
}

.hero__icon::after {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1.5px;
  background: var(--gradient-brand);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0.65;
}

.hero__icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.hero h1 {
  margin: 0;
  font-size: clamp(1.8rem, 3.4vw, 2.6rem);
}

/* ---------- Page grid (content + sidebar) ---------- */

.page-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 308px;
  gap: var(--space-6);
  padding: var(--space-7) 0;
  align-items: start;
}

@media (max-width: 900px) {
  .page-grid {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    top: auto;
  }
}

.page-content {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-7);
  box-shadow: var(--shadow-md);
  min-width: 0;
  overflow: hidden;
}

.page-content::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--gradient-brand);
}

.page-content > h3:first-child,
.page-content > h2:first-child {
  margin-top: 0;
}

.page-content img.img-inline {
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  margin-bottom: var(--space-4);
}

.page-content img.lead-image {
  display: block;
  width: 100%;
  max-width: 560px;
  margin-bottom: var(--space-5);
}

@media (max-width: 560px) {
  .page-content {
    padding: var(--space-5);
  }

  .hero {
    padding: var(--space-6) 0 var(--space-5);
  }

  .hero__icon {
    width: 64px;
    height: 64px;
  }
}

.section-full {
  padding: var(--space-7) 0;
}

/* ---------- Sidebar ---------- */

.sidebar {
  position: sticky;
  top: calc(120px + var(--space-4));
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.sidebar-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), border-color var(--transition-base);
}

.sidebar-card:hover {
  border-color: color-mix(in srgb, var(--color-brand) 35%, var(--color-border));
  box-shadow: var(--glow-brand);
}

.sidebar-card h4 {
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-faint);
  margin-bottom: var(--space-3);
}

.toc {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toc a {
  display: block;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--color-text-muted);
  border-left: 2px solid transparent;
  transition: background var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast), padding-left var(--transition-fast);
}

.toc a:hover {
  background: var(--color-brand-tint);
  color: var(--color-text);
  padding-left: var(--space-4);
}

.toc a.is-active {
  background: var(--color-brand-tint);
  color: var(--color-brand-light);
  border-left-color: var(--color-brand);
}

[data-theme="light"] .toc a.is-active {
  color: var(--color-brand-dark);
}

/* ---------- Footer ---------- */

.site-footer {
  position: relative;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-8);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-brand);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: var(--space-6);
  padding: var(--space-8) 0 var(--space-6);
}

.site-footer__grid h5 {
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-faint);
  margin-bottom: var(--space-4);
}

.site-footer__grid ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.site-footer__grid a {
  color: var(--color-text-muted);
  font-size: 0.88rem;
  font-weight: 500;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.site-footer__grid a:hover {
  color: var(--color-brand-light);
  padding-left: 4px;
}

[data-theme="light"] .site-footer__grid a:hover {
  color: var(--color-brand);
}

.site-footer__bottom {
  border-top: 1px solid var(--color-border);
  padding: var(--space-5) 0;
  font-size: 0.8rem;
  color: var(--color-text-faint);
  text-align: center;
}

@media (max-width: 760px) {
  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
  }
  .hero__inner {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-4);
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }

  .site-header__bar {
    gap: var(--space-3);
  }

  .theme-toggle #theme-text {
    display: none;
  }

  .theme-toggle {
    padding: var(--space-2) var(--space-3);
  }
}