.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--topbar-height);
  background: var(--md-surface);
  border-bottom: 1px solid var(--overlay-bg);
  display: none;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  box-shadow: var(--shadow-default);
  z-index: 101;
}

.topbar-brand {
  display: flex;
  align-items: center;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--md-primary);
  text-decoration: none;
}

.topbar-brand img {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  margin-left: 8px;
}

.topbar-nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.topbar-nav a {
  text-decoration: none;
  color: var(--md-text);
  padding: 0.4rem 0.8rem;
  border-radius: var(--md-border-radius);
  transition: background-color 0.2s, color 0.2s;
  font-size: 0.9rem;
}

.topbar-nav a:hover,
.topbar-nav a.active {
  background-color: var(--overlay-bg);
  color: var(--md-accent);
}

.menu-button {
  margin-right: 1rem;
  cursor: pointer;
  color: var(--md-text);
  display: none;
}

.mobile-menu {
  position: fixed;
  top: var(--topbar-height);
  left: 0;
  right: 0;
  background: var(--md-surface);
  border-bottom: 1px solid var(--overlay-bg);
  box-shadow: var(--shadow-default);
  display: none;
  flex-direction: column;
  padding: 1rem;
  z-index: 100;
}

.mobile-menu a {
  text-decoration: none;
  color: var(--md-text);
  padding: 0.75rem 1rem;
  border-radius: var(--md-border-radius);
  transition: background-color 0.2s, color 0.2s;
  margin-bottom: 0.5rem;
}

.mobile-menu a:hover,
.mobile-menu a.active {
  background-color: var(--overlay-bg);
  color: var(--md-accent);
}

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

@media (max-width: 800px) and (orientation: portrait) {
  .sidebar {
    display: none !important;
  }
  
  .topbar {
    display: flex;
  }
  
  .topbar-nav {
    display: none;
  }
  
  .menu-button {
    display: block;
  }
  
  main {
    margin-left: 0;
    padding-top: calc(var(--topbar-height) + 2rem);
    padding-left: 2rem;
    padding-right: 2rem;
    padding-bottom: 3rem;
  }
  
  footer {
    margin-left: 0;
  }
}