nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  display: flex; align-items: center; justify-content: space-between;
  padding: 1.5rem 4rem;
  transition: all 0.4s var(--ease);
  background: #ffffff;
  color: var(--text-primary);
  border-bottom: 1px solid rgba(0,0,0,0.03);
}
nav.scrolled {
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  border-bottom: 1px solid var(--green-border);
  padding: 0.85rem 4rem;
  color: var(--text-primary);
  box-shadow: 0 8px 48px rgba(7, 26, 14, 0.08);
}

.nav-logo { display: flex; align-items: center; gap: 0.8rem; }
.nav-logo-mark {
  width: 40px; height: 40px;
  background: var(--green);
  border-radius: 10px;
  display: grid; place-items: center;
  font-family: var(--serif); font-size: 1.1rem;
  font-weight: 900; color: #fff;
  box-shadow: 0 4px 16px var(--green-glow);
  transition: transform var(--t-med) var(--ease);
}
.nav-logo:hover .nav-logo-mark { transform: scale(1.08); }
.nav-logo-name {
  font-family: var(--serif);
  font-size: 1.45rem; font-weight: 700;
  color: inherit; line-height: 1.1;
}
.nav-logo-sub {
  font-family: var(--mono); font-size: 0.6rem;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: inherit; opacity: 0.7; display: block;
}

.nav-links { display: flex; align-items: center; gap: 2.2rem; }
.nav-links a {
  font-size: 1.1rem; font-weight: 600;
  color: inherit; opacity: 0.85;
  position: relative; transition: all 0.2s;
}
.nav-links a::after {
  content: ''; position: absolute;
  bottom: -4px; left: 0; right: 0;
  height: 2px; background: currentColor;
  transform: scaleX(0); transform-origin: left;
  transition: transform 0.25s var(--ease);
}
.nav-links a:hover { opacity: 1; transform: translateY(-1px); }
.nav-links a:hover::after,
.nav-links a.active::after { transform: scaleX(1); }
.nav-links a.active { opacity: 1; color: var(--green-bright); }

/* Mobile hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none; border: none;
  cursor: none; padding: 4px;
}
.nav-hamburger span {
  display: block; width: 24px; height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--t-med) var(--ease);
}
.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile nav overlay */
.nav-mobile {
  display: none;
  position: fixed; inset: 0; z-index: 999;
  background: var(--green-deep, #0d3311);
  backdrop-filter: none;
  flex-direction: column; align-items: center; justify-content: flex-start;
  gap: 1.25rem;
  padding: 3rem 1.5rem;
  overflow-y: auto;
  animation: fade-up 0.3s var(--ease) forwards;
}
.nav-mobile.open { display: flex; }
.nav-mobile a {
  font-family: var(--serif); font-size: 1.55rem; font-weight: 700;
  color: #ffffff; transition: color var(--t-fast);
  min-height: 44px;
  display: flex; align-items: center;
  -webkit-tap-highlight-color: transparent;
}
.nav-mobile a:hover { color: #fbbf24; }
.nav-mobile .btn-donate {
  font-size: 1rem; padding: 0.8rem 2rem;
  min-height: 44px; display: flex; align-items: center;
}

/* Tablet: hide links, show hamburger */
@media (max-width: 900px) {
  nav { padding: 1rem 2rem; }
  nav.scrolled { padding: 0.8rem 2rem; }
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
}

/* Mobile: adjust padding, hide donate in top nav */
@media (max-width: 767px) {
  nav { padding: 1rem 1.5rem; }
  nav.scrolled { padding: 0.75rem 1.5rem; }
  nav > a.btn-donate,
  nav > a.btn.btn-donate { display: none; }
  .nav-logo-sub { display: none; }
}

@media (max-width: 479px) {
  nav { padding: 1rem 1rem; }
  nav.scrolled { padding: 0.7rem 1rem; }
}