/* ==========================================================
   Silakab — Header / Navigation / Footer
   ========================================================== */

/* ── Site Header ── */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: var(--space-md) 0;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: background var(--duration-fast) var(--ease-smooth);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.site-logo img {
  height: 36px;
  width: auto;
}

/* ── Desktop Nav ── */

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-link {
  font-family: var(--font-body);
  font-size: var(--text-body-sm);
  font-weight: 600;
  color: var(--color-muted-light);
  letter-spacing: 0.02em;
  transition: color var(--duration-fast) var(--ease-smooth);
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-white);
}

/* Nav underline effect */
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-brand);
  transition: width var(--duration-fast) var(--ease-smooth);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Nav CTA button */
.nav-cta {
  margin-left: var(--space-md);
}

.nav-cta .btn {
  padding: 10px 24px;
  font-size: var(--text-body-sm);
}

/* ── Dropdown ── */

.nav-dropdown {
  position: relative;
}

.nav-dropdown-trigger {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
}

.nav-dropdown-trigger svg {
  width: 14px;
  height: 14px;
  transition: transform var(--duration-fast) var(--ease-smooth);
}

.nav-dropdown:hover .nav-dropdown-trigger svg,
.nav-dropdown.is-open .nav-dropdown-trigger svg {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 12px);
  left: 50%;
  transform: translateX(-50%);
  min-width: 240px;
  background: var(--color-dark-surface);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  padding: var(--space-sm) 0;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(8px);
  transition:
    opacity var(--duration-fast) var(--ease-smooth),
    transform var(--duration-fast) var(--ease-smooth),
    visibility var(--duration-fast);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown.is-open .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown-menu a {
  display: block;
  padding: 10px var(--space-lg);
  font-size: var(--text-body-sm);
  color: var(--color-muted-light);
  transition: all var(--duration-fast) var(--ease-smooth);
}

.nav-dropdown-menu a:hover {
  color: var(--color-white);
  background: rgba(0, 165, 235, 0.08);
}

/* ── Hamburger Toggle ── */

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  cursor: pointer;
  position: relative;
  z-index: 1002;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-white);
  border-radius: 2px;
  transition: all var(--duration-fast) var(--ease-smooth);
  transform-origin: center;
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── Mobile Nav ── */

@media (max-width: 1024px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 0;
    right: 0;
    width: 100%;
    max-width: 360px;
    height: 100vh;
    background: var(--color-dark-surface);
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    padding: 100px var(--space-xl) var(--space-xl);
    gap: 0;
    transform: translateX(100%);
    transition: transform var(--duration-fast) var(--ease-smooth);
    border-left: 1px solid rgba(255, 255, 255, 0.06);
    overflow-y: auto;
  }

  .nav-menu.is-open {
    transform: translateX(0);
  }

  .nav-menu .nav-link {
    display: block;
    width: 100%;
    padding: var(--space-md) 0;
    font-size: var(--text-body);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .nav-menu .nav-link::after {
    display: none;
  }

  .nav-menu .nav-dropdown-trigger {
    display: flex;
    align-items: center;
  }

  .nav-cta {
    margin-left: 0;
    margin-top: var(--space-lg);
    width: 100%;
  }

  .nav-cta .btn {
    width: 100%;
    text-align: center;
  }

  /* Mobile dropdown */
  .nav-dropdown-menu {
    position: static;
    transform: none;
    opacity: 1;
    visibility: visible;
    background: transparent;
    border: none;
    box-shadow: none;
    padding: 0;
    min-width: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--duration-fast) var(--ease-smooth);
  }

  .nav-dropdown.is-open .nav-dropdown-menu {
    max-height: 500px;
    transform: none;
  }

  .nav-dropdown-menu a {
    padding: var(--space-sm) var(--space-lg);
    font-size: var(--text-body-sm);
  }

  /* Body scroll lock when nav is open */
  body.nav-open {
    overflow: hidden;
  }
}

/* ── Mobile overlay ── */

@media (max-width: 1024px) {
  .nav-menu::before {
    content: '';
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: -1;
    opacity: 0;
    transition: opacity var(--duration-fast) var(--ease-smooth);
    pointer-events: none;
  }

  .nav-menu.is-open::before {
    opacity: 1;
  }
}

/* ── Skip to content (accessibility) ── */

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: var(--radius-sm);
  font-weight: 600;
  z-index: 10000;
  transition: top var(--duration-fast) var(--ease-smooth);
}

.skip-link:focus {
  top: var(--space-md);
}

/* ==========================================================
   Footer
   ========================================================== */

.site-footer {
  background-color: var(--color-dark-surface);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: var(--space-4xl) 0 var(--space-xl);
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: var(--space-2xl);
  padding-bottom: var(--space-3xl);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

/* Footer brand column */
.footer-brand .site-logo {
  margin-bottom: var(--space-lg);
}

.footer-tagline {
  color: var(--color-muted-light);
  font-size: var(--text-body-sm);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
  max-width: 300px;
}

.footer-patents {
  font-size: var(--text-caption);
  color: rgba(255, 255, 255, 0.35);
  line-height: 1.8;
}

/* Footer nav columns */
.footer-nav h4 {
  color: var(--color-white);
  font-size: var(--text-body-sm);
  font-weight: 700;
  margin-bottom: var(--space-lg);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-nav a {
  display: block;
  padding: 6px 0;
  color: var(--color-muted-light);
  font-size: var(--text-body-sm);
  transition: color var(--duration-fast) var(--ease-smooth);
}

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

/* Footer bottom bar */
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-xl);
  font-size: var(--text-caption);
  color: rgba(255, 255, 255, 0.35);
}

/* ── Footer responsive ── */

@media (max-width: 1024px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .footer-top {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }
}