/* Footer */
.footer {
  padding: var(--space-10) 0 var(--space-6);
  background: var(--color-ink);
  color: var(--color-text-light);
  position: relative;
  overflow: hidden;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-moss), transparent);
  opacity: 0.3;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.footer-brand {
  margin-bottom: var(--space-6);
}

.footer-logo {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: var(--space-2);
  opacity: 0.8;
}

.footer-logo-en {
  display: block;
  width: 120px;
  height: auto;
}

.footer-logo-cn {
  display: none;
  width: auto;
  height: 50px;
}

body.lang-cn .footer-logo-en {
  display: none;
}

body.lang-cn .footer-logo-cn {
  display: block;
}

.footer-name {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  letter-spacing: 0.4em;
  color: var(--color-text-light-muted);
  margin-bottom: var(--space-1);
}

.footer-tagline {
  font-family: var(--font-body);
  font-size: 0.75rem;
  color: var(--color-text-light-muted);
  opacity: 0.7;
  letter-spacing: 0.15em;
}

.footer-links {
  display: flex;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
  justify-content: center;
}

.footer-link {
  color: var(--color-text-light-muted);
  text-decoration: none;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  transition: var(--transition-base);
  position: relative;
}

.footer-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-moss);
  transition: width var(--transition-base);
}

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

.footer-link:hover::after {
  width: 100%;
}

.footer-bottom {
  padding-top: var(--space-5);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  width: 100%;
  display: flex;
  justify-content: center;
}

.footer-copyright {
  font-family: var(--font-body);
  font-size: 0.6875rem;
  color: var(--color-text-light-muted);
  opacity: 0.5;
  letter-spacing: 0.1em;
}

/* Back to top button */
.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-ink);
  border: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-base);
  z-index: 90;
}

.back-to-top.visible {
  opacity: 0.7;
  visibility: visible;
}

.back-to-top:hover {
  opacity: 1;
  transform: translateY(-2px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
  stroke: var(--color-text-light);
  opacity: 0.8;
}

@media (max-width: 768px) {
  .footer {
    padding: var(--space-8) 0 var(--space-5);
  }

  .footer-links {
    gap: var(--space-4);
  }

  .back-to-top {
    bottom: var(--space-4);
    right: var(--space-4);
  }
}