/* ── Responsive ── */
@media (max-width: 1200px) {
  .feat-grid { grid-template-columns: 1fr; }
  .regression-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 900px) {
  .predict-layout { grid-template-columns: 1fr; }
  .hero-top { flex-direction: column; }
  .hero-stats { flex-wrap: wrap; }
  .lb-row { grid-template-columns: 28px 1fr 70px 70px; }
  .lb-row > *:nth-child(5), .lb-row > *:nth-child(6) { display: none; }
  .regression-grid { grid-template-columns: 1fr; }
  nav { padding: 0 16px; gap: 8px; }
  .nav-badge { display: none; }
  .page { padding: 20px 16px; }
  .hero { padding: 32px 16px 24px; }
}

@media (max-width: 600px) {
  .nav-tabs { gap: 2px; }
  .nav-tab { padding: 6px 10px; font-size: 11px; letter-spacing: 1px; }
  .hero-title { font-size: 28px !important; }
  .class-guide { gap: 6px; }
  .class-pill { font-size: 10px; padding: 4px 10px; }
  .about-grid { grid-template-columns: 1fr; }
  .dataset-stats { grid-template-columns: repeat(2, 1fr); }
  footer { flex-direction: column; gap: 6px; text-align: center; }
  
  /* Key mobile fixes */
  .leaderboard-wrap { overflow-x: auto; }
  .leaderboard { min-width: 600px; } /* allow horizontal scroll */
  .hero-stats { grid-template-columns: 1fr 1fr; } /* 2-col on mobile */
  .prediction-grid { grid-template-columns: 1fr; } /* stack on mobile */
}