/* ═══════════════════════════════════════════════════════════════════════════
   PHYSICSFORUM.ORG — FOOTER STYLES
   ═══════════════════════════════════════════════════════════════════════════ */

.pf-footer {
  background: var(--color-space-navy);
  color: var(--color-neutron-grey);
  padding: var(--space-16) var(--space-8) var(--space-8);
  position: relative;
  overflow: hidden;
}

/* Background grid pattern */
.pf-footer::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(148,163,184,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148,163,184,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.footer-inner {
  max-width: 1440px;
  margin: 0 auto;
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: var(--space-8);
  padding-bottom: var(--space-8);
  margin-bottom: var(--space-8);
  border-bottom: 1px solid rgba(245,158,11,0.2);
}

.footer-col h4 {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-quantum-gold);
  margin-bottom: var(--space-4);
  font-weight: 700;
}

/* Brand column */
.footer-brand .footer-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}
.footer-brand .footer-logo svg {
  width: 48px;
  height: 48px;
  animation: atomSpin 20s linear infinite;
}
@keyframes atomSpin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}
.footer-brand .tagline {
  font-size: var(--text-sm);
  color: var(--color-neutron-grey);
  margin-bottom: var(--space-1);
}
.footer-brand .description {
  font-size: var(--text-sm);
  line-height: 1.6;
  margin-bottom: var(--space-4);
  max-width: 280px;
}
.footer-socials {
  display: flex;
  gap: var(--space-2);
}
.footer-socials a {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  background: rgba(255,255,255,0.06);
  color: var(--color-neutron-grey);
  transition: var(--transition-fast);
}
.footer-socials a:hover {
  background: rgba(245,158,11,0.15);
  color: var(--color-quantum-gold);
}

/* Link columns */
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: var(--space-2); }
.footer-col a {
  font-size: var(--text-sm);
  color: var(--color-neutron-grey);
  transition: var(--transition-fast);
  display: inline-block;
  padding: var(--space-1) 0;
}
.footer-col a:hover {
  color: #FFFFFF;
  text-decoration: none;
  transform: translateX(2px);
}

/* Bottom bar */
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: var(--text-xs);
  flex-wrap: wrap;
  gap: var(--space-4);
}
.footer-bottom .copyright {
  color: var(--color-neutron-grey);
}
.footer-bottom .footer-links {
  display: flex;
  gap: var(--space-4);
}
.footer-bottom .footer-links a {
  color: var(--color-neutron-grey);
  transition: var(--transition-fast);
}
.footer-bottom .footer-links a:hover { color: #FFFFFF; }

.language-selector {
  padding: var(--space-1) var(--space-3);
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-md);
  color: var(--color-neutron-grey);
  font-size: var(--text-xs);
  cursor: pointer;
}

/* Responsive */
@media (max-width: 1023px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-6);
  }
  .footer-brand { grid-column: span 2; }
}
@media (max-width: 639px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
  .footer-brand { grid-column: span 1; }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}