/* ==========================================================================
   Site header / navigation
   ========================================================================== */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 30, 20, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(111, 186, 44, 0.25);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  color: var(--color-on-dark);
}
.nav-logo:hover { opacity: 0.85; }
.nav-logo-mark {
  display: block;
  width: 40px;
  color: var(--color-accent-2);
  flex-shrink: 0;
}
.nav-logo-mark svg { display: block; width: 100%; }
.nav-logo-text { display: flex; flex-direction: column; line-height: 1.3; }
.nav-logo-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.06em;
}
.nav-logo-sub {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-on-dark-muted);
}

/* Menu */
.nav-menu ul {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.2vw, 2rem);
  list-style: none;
}
.nav-menu a {
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--color-on-dark);
  text-decoration: none;
  padding: 0.4em 0;
  position: relative;
}
.nav-menu a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  background: var(--color-accent-2);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}
.nav-menu a:hover { opacity: 1; }
.nav-menu a:hover::after { transform: scaleX(1); }

.nav-en-btn {
  border: 1.5px solid var(--color-accent-2);
  border-radius: 999px;
  padding: 0.35em 1.1em !important;
  color: var(--color-accent-2) !important;
}
.nav-en-btn::after { display: none; }
.nav-en-btn:hover { background: rgba(111, 186, 44, 0.15); }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: none;
  border: none;
  cursor: pointer;
}
.hamburger span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-on-dark);
  transition: transform var(--transition), opacity var(--transition);
}

@media (max-width: 900px) {
  .hamburger { display: flex; }

  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--color-deep-2);
    border-bottom: 1px solid rgba(111, 186, 44, 0.25);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
  }
  .nav-menu.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  .nav-menu ul {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.75rem var(--container-pad) 1.5rem;
  }
  .nav-menu li { border-bottom: 1px solid rgba(255, 255, 255, 0.08); }
  .nav-menu li:last-child { border-bottom: none; padding-top: 1rem; }
  .nav-menu a { display: block; padding: 0.9em 0.25em; }
  .nav-menu a::after { display: none; }
  .nav-en-btn { display: inline-block !important; text-align: center; }

  .hamburger.is-open span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
  .hamburger.is-open span:nth-child(2) { opacity: 0; }
  .hamburger.is-open span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
}