/* Footer */
.footer {
  background-color: var(--color-bg-secondary);
  padding-top: var(--spacing-8);
  border-top: 1px solid var(--color-border);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.footer-top {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-6);
  padding-bottom: var(--spacing-6);
  border-bottom: 1px solid var(--color-border);
}

.footer-col {
  margin-bottom: var(--spacing-4);
}

.footer-logo {
  display: flex;
  align-items: center;
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-primary-500);
  margin-bottom: var(--spacing-3);
}

.footer-logo .logo-icon {
  margin-right: var(--spacing-2);
}

.footer-desc {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-4);
}

.footer-social {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3.6rem;
  height: 3.6rem;
  border-radius: var(--border-radius-full);
  background-color: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.footer-social a:hover {
  background-color: var(--color-primary-500);
  color: white;
}

.footer-title {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-4);
  position: relative;
  display: inline-block;
}

.footer-title::after {
  content: '';
  position: absolute;
  bottom: -0.8rem;
  left: 0;
  width: 4rem;
  height: 0.2rem;
  background-color: var(--color-primary-500);
  border-radius: var(--border-radius-full);
}

.footer-links li {
  margin-bottom: var(--spacing-2);
}

.footer-links a {
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-primary-500);
}

.footer-contact li {
  display: flex;
  align-items: flex-start;
  margin-bottom: var(--spacing-3);
  color: var(--color-text-secondary);
}

.footer-contact li svg {
  margin-right: var(--spacing-2);
  margin-top: 0.3rem;
  flex-shrink: 0;
  color: var(--color-primary-500);
}

.footer-contact a {
  color: var(--color-text-secondary);
}

.footer-contact a:hover {
  color: var(--color-primary-500);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-4) 0;
  text-align: center;
}

.copyright {
  color: var(--color-text-tertiary);
  margin-bottom: var(--spacing-3);
}

.footer-bottom-links {
  display: flex;
  gap: var(--spacing-4);
}

.footer-bottom-links a {
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
}

.footer-bottom-links a:hover {
  color: var(--color-primary-500);
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 3rem;
  right: 3rem;
  width: 4.8rem;
  height: 4.8rem;
  background-color: var(--color-primary-500);
  color: white;
  border-radius: var(--border-radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(1rem);
  transition: opacity var(--transition-normal), visibility var(--transition-normal), transform var(--transition-normal), background-color var(--transition-fast);
  z-index: var(--z-index-fixed);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background-color: var(--color-primary-600);
}

@media (min-width: 768px) {
  .footer-top {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-bottom {
    flex-direction: row;
    text-align: left;
  }
  
  .copyright {
    margin-bottom: 0;
  }
}

@media (min-width: 1024px) {
  .footer-top {
    grid-template-columns: 3fr 1fr 1fr 2fr;
  }
}