.main-nav {
  background-color: var(--color-surface);
  box-shadow: var(--shadow);
}

[data-theme="dark"] .main-nav {
  background-color: var(--color-surface-dark);
  border-bottom: 1px solid var(--color-border-dark);
}

.main-nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-4);
  padding-top: var(--spacing-4);
  padding-bottom: var(--spacing-4);
  position: relative;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-2);
  z-index: 10;
}

.nav-toggle-icon {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  position: relative;
  transition: background-color 0.2s;
}

[data-theme="dark"] .nav-toggle-icon { background-color: var(--color-text-dark); }

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  left: 0;
  transition: transform 0.2s;
}

[data-theme="dark"] .nav-toggle-icon::before,
[data-theme="dark"] .nav-toggle-icon::after { background-color: var(--color-text-dark); }

.nav-toggle-icon::before { top: -8px; }
.nav-toggle-icon::after { bottom: -8px; }

.nav-toggle.active .nav-toggle-icon { background-color: transparent; }
.nav-toggle.active .nav-toggle-icon::before { transform: translateY(8px) rotate(45deg); }
.nav-toggle.active .nav-toggle-icon::after { transform: translateY(-8px) rotate(-45deg); }

.nav-brand {
  font-weight: bold;
  font-size: 1.25rem;
  color: var(--color-text);
  white-space: nowrap;
}

[data-theme="dark"] .nav-brand { color: var(--color-text-dark); }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
}

.nav-link {
  color: var(--color-text-muted);
  white-space: nowrap;
}

.nav-welcome {
  font-weight: 500;
  color: var(--color-text);
}

[data-theme="dark"] .nav-welcome { color: var(--color-text-dark); }

@media (max-width: 767px) {
  .nav-toggle { display: block; }

  .nav-links {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    background-color: var(--color-surface);
    padding: var(--spacing-16) var(--spacing-6) var(--spacing-8);
    z-index: 100;
    align-items: flex-start;
    overflow-y: auto;
    -ms-overflow-style: none;
    scrollbar-width: none;
    transition: transform 0.3s ease-in-out;
    transform: translateX(100%);
  }

  .nav-links::-webkit-scrollbar { display: none; }

  [data-theme="dark"] .nav-links { background-color: var(--color-surface-dark); border-color: var(--color-border-dark); }

  .nav-links:not(.hidden-mobile) { transform: translateX(0); }
  .nav-links.hidden-mobile { transform: translateX(100%); }

  .nav-toggle { position: relative; z-index: 101; }

  .nav-link, .theme-toggle-wrapper {
    width: 100%;
    padding: var(--spacing-4) 0;
    border-bottom: 1px solid var(--color-border);
    font-size: 1.125rem;
  }

  [data-theme="dark"] .nav-link, [data-theme="dark"] .theme-toggle-wrapper { border-bottom-color: var(--color-border-dark); }
  .nav-link:last-child { border-bottom: none; }
}

[data-theme="dark"] .nav-link { color: var(--color-text-dark-light); }
.nav-link:hover { color: var(--color-text); }
[data-theme="dark"] .nav-link:hover { color: var(--color-text-dark); }

/* Helper to prevent background scrolling when menu is open */
body.menu-open { overflow: hidden; }