header {
  padding: 0 24px;
  padding-top: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
  position: sticky;
  top: 0;
  z-index: 100;
  font-family: var(--font-mono);
}

header .nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

header .nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 18px;
  color: var(--color-text);
  text-decoration: none;
  white-space: nowrap;
}

header .nav-logo img {
  width: 30px;
  height: 30px;
  flex-shrink: 0;
}

header .nav-links {
  display: flex;
  gap: 24px;
}

header .nav-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-sm);
}

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

header .nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

header .btn {
  padding: 8px 16px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-sm);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}

header .btn:hover {
  background: var(--color-bg-subtle);
  border-color: var(--color-border-input);
  color: var(--color-text);
}

header .btn-active {
  background: var(--color-bg-subtle);
  color: var(--color-text);
  border-color: var(--color-border-input);
  cursor: default;
  font-weight: 500;
}

header .btn-active:hover {
  background: var(--color-bg-muted);
  border-color: var(--color-border-input);
}

header .btn-primary {
  background: var(--color-text);
  color: var(--color-bg);
  border-color: var(--color-text);
}

header .btn-primary:hover {
  opacity: 0.85;
}

header .btn .btn-text {
  display: inline;
}

@media (max-width: 768px) {
  header {
    padding: 0 12px;
    padding-top: 10px;
    padding-bottom: 10px;
  }

  header .nav-links {
    gap: 16px;
  }

  header .nav-links a {
    font-size: var(--text-xs);
  }

  header .btn .btn-text {
    display: none;
  }

  header .btn {
    padding: 8px 10px;
  }

  header .nav-left {
    gap: 12px;
  }

  header .nav-right {
    gap: 6px;
  }

  header .nav-logo {
    font-size: 16px;
    min-width: 0;
    overflow: hidden;
  }

  header .nav-logo-text {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 80px;
  }
}