.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-light);
  padding: 0 80px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-logo {
  font-family: 'C059', serif;
  font-size: 26px;
  font-weight: 400;
  color: var(--text-primary);
}

.logo-indepth {
  font-style: italic;
  letter-spacing: -0.03em;
}

.header-nav {
  display: flex;
  gap: 32px;
  align-items: center;
}

.header-nav a {
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #888;
  padding-bottom: 4px;
  border-bottom: 1.5px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

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

.header-nav a.active {
  color: var(--text-primary);
  border-bottom-color: var(--highlight);
}

.header-right {
  display: flex;
  align-items: center;
}

/* Mobile hamburger */
.header-hamburger {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 4px;
  cursor: pointer;
}

.header-hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-primary);
  transition: transform 0.2s, opacity 0.2s;
}

.header-hamburger.open span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.header-hamburger.open span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.header-hamburger.open span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Mobile nav overlay */
.mobile-nav {
  display: none;
  position: fixed;
  top: 56px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  z-index: 99;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 32px;
}

.mobile-nav.open {
  display: flex;
}

.mobile-nav a {
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #888;
  padding-bottom: 4px;
  border-bottom: 1.5px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.mobile-nav a.active {
  color: var(--text-primary);
  border-bottom-color: var(--highlight);
}

@media (max-width: 768px) {
  .site-header {
    padding: 0 16px;
  }

  .header-nav {
    display: none;
  }

  .header-hamburger {
    display: flex;
  }

  .header-right .header-auth-btn {
    display: none;
  }

  .mobile-nav .mobile-auth-btn {
    margin-top: 8px;
  }
}

@media (min-width: 769px) {
  .mobile-nav {
    display: none !important;
  }
}