.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(229, 231, 235, 0.9);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
}

.nav {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-primary);
  font-size: 1.125rem;
  font-weight: 750;
  text-decoration: none;
}

.brand-mark {
  display: block;
  width: 2rem;
  height: 2rem;
  border-radius: 0.6rem;
  box-shadow: var(--shadow);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
}

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

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.25rem;
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  font-weight: 700;
  text-decoration: none;
  transition: transform 160ms ease, background-color 160ms ease, border-color 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  color: #ffffff;
  background: var(--primary-color);
}

.button-primary:hover {
  background: var(--secondary-color);
}

.button-secondary {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.55);
}

.button-secondary:hover {
  border-color: #ffffff;
  background: rgba(255, 255, 255, 0.08);
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--primary-color);
  font-weight: 700;
  text-decoration: none;
}

.text-link:hover {
  color: var(--secondary-color);
}

.site-footer {
  padding: 2rem 0;
  color: #d1d5db;
  background: var(--background-dark);
}

.footer-layout {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
}

@media (max-width: 640px) {
  .nav {
    min-height: auto;
    padding: 1rem 0;
    align-items: flex-start;
  }

  .nav-links {
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.5rem 1rem;
  }

  .footer-layout {
    flex-direction: column;
  }
}

@media (max-width: 460px) {
  .nav {
    flex-direction: column;
  }

  .nav-links {
    justify-content: flex-start;
  }
}