/* header.css */
header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-title {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 800;
  color: var(--accent);
  text-decoration: none;
  margin: 0;
}

.header-controls {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 2rem;
  margin: 0;
}

nav a {
  font-family: var(--font-mono);
  font-size: var(--fs-nav);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  transition: var(--transition);
}

nav a:hover,
nav a.active {
  color: var(--accent);
}

.theme-toggle {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: var(--fs-nav);
  transition: var(--transition);
}

.theme-toggle:hover {
  background: var(--border);
  color: var(--accent);
}

@media (max-width: 768px) {
  .header-container {
    flex-wrap: wrap;
    gap: 1rem;
  }

  nav ul {
    order: 3;
    width: 100%;
    gap: 1rem;
    flex-wrap: wrap;
  }

  .header-controls {
    gap: 1rem;
  }
}