.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(33, 103, 120, 0.97);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(10px);
  transition: background-color var(--transition-default), box-shadow var(--transition-default), border-color var(--transition-default);
}

.site-header.is-scrolled {
  background: rgba(24, 77, 90, 0.98);
  box-shadow: 0 18px 35px rgba(11, 32, 38, 0.22);
}

.header-shell {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 1rem;
  min-height: var(--header-height);
  padding-block: 1rem;
  transition: min-height var(--transition-default), padding var(--transition-default);
}

.site-header.is-scrolled .header-shell {
  min-height: 78px;
  padding-block: 0.75rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.95rem;
  color: var(--color-white);
}

.brand:hover {
  color: var(--color-white);
}

.brand-logo {
  width: auto;
  height: 64px;
  overflow: visible;
  transition: height var(--transition-default), transform var(--transition-default);
}

.site-header.is-scrolled .brand-logo {
  height: 50px;
}

.logo-electron {
  filter: drop-shadow(0 0 3px rgba(255, 255, 255, 0.4));
  transition: opacity 120ms linear;
}

.logo-electron-back {
  opacity: 0;
}

.brand-copy {
  display: grid;
  gap: 0;
}

.brand-copy strong {
  font-size: clamp(1.3rem, 2vw, 1.7rem);
  line-height: 1;
}

.nav-toggle {
  display: inline-grid;
  gap: 0.32rem;
  width: 52px;
  height: 52px;
  padding: 0.75rem;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.16);
}

.nav-toggle span:not(.sr-only) {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 999px;
  background: var(--color-white);
  transition: transform var(--transition-default), opacity var(--transition-default);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  transform: translateY(0.42rem) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(4) {
  transform: translateY(-0.42rem) rotate(-45deg);
}

.site-nav {
  position: absolute;
  top: calc(100% + 0.6rem);
  left: 0;
  right: 0;
  display: none;
  flex-direction: column;
  gap: 0.8rem;
  max-height: min(calc(100dvh - var(--header-height) - 1.2rem), 78vh);
  padding: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 24px;
  background: rgba(24, 77, 90, 0.98);
  box-shadow: var(--shadow-strong);
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

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

.nav-item {
  position: relative;
  display: grid;
  gap: 0.45rem;
  padding: 0.25rem 0;
}

.nav-link,
.sub-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: flex-start;
  color: rgba(255, 255, 255, 0.9);
  font-weight: 700;
}

.nav-link {
  min-height: 3.1rem;
  width: fit-content;
  padding: 0.75rem 1rem;
  border-radius: 999px;
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.08);
  font-size: 1.22rem;
  letter-spacing: 0.01em;
}

.nav-link:hover,
.nav-link:focus-visible,
.nav-item:hover > .nav-link,
.nav-item:focus-within > .nav-link,
.nav-link[aria-current="page"] {
  color: var(--color-primary-deep);
  background: var(--color-accent);
}

.sub-nav {
  display: grid;
  gap: 0.45rem;
  padding-left: 0;
}

.sub-nav a {
  justify-content: flex-start;
  min-height: 2.7rem;
  padding: 0.55rem 0.9rem;
  border-radius: 18px;
  background: rgba(33, 103, 120, 0.3);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.2;
}

.sub-nav a:hover,
.sub-nav a:focus-visible {
  color: var(--color-primary-deep);
  background: rgba(255, 191, 0, 0.96);
}

@media (min-width: 900px) {
  .header-shell {
    grid-template-columns: auto 1fr;
  }

  .nav-toggle {
    display: none;
  }

  .site-nav {
    position: static;
    display: flex;
    flex-direction: row;
    justify-content: flex-end;
    align-items: center;
    gap: 0.35rem;
    max-height: none;
    margin-right: clamp(0.8rem, 2vw, 1.6rem);
    padding: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    overflow: visible;
  }

  .nav-link {
    min-height: 3rem;
    width: auto;
    padding: 0.75rem 1rem;
    padding-inline: 1.1rem;
    border-radius: 999px;
    color: rgba(255, 255, 255, 0.9);
    font-size: 1rem;
  }

  .nav-item {
    display: block;
    padding: 0;
  }

  .nav-item::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    height: 0.85rem;
  }

  .sub-nav {
    position: absolute;
    top: calc(100% + 0.35rem);
    left: 50%;
    min-width: 220px;
    padding: 0.7rem;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 20px;
    background: rgba(24, 77, 90, 0.99);
    box-shadow: var(--shadow-strong);
    opacity: 0;
    pointer-events: none;
    transform: translate(-50%, 8px);
    transition: opacity var(--transition-default), transform var(--transition-default);
    overflow: visible;
    max-height: none;
  }

  .sub-nav a {
    min-height: 2.5rem;
    padding: 0.45rem 0.8rem;
    border-radius: 16px;
    background: transparent;
    font-size: 0.98rem;
    font-weight: 600;
  }

  .nav-item:hover .sub-nav,
  .nav-item:focus-within .sub-nav {
    opacity: 1;
    pointer-events: auto;
    transform: translate(-50%, 0);
  }
}

@media (max-width: 899px) and (max-height: 760px) {
  .site-nav {
    max-height: calc(100dvh - 5.2rem);
  }
}

@media (max-width: 640px) {
  .brand-logo {
    height: 56px;
  }
}