@media (max-width: 820px) {
  :root { --section-pt: 4.5rem; }

  main { padding: 1.5rem 1.2rem 7rem; }
  .about-grid         { grid-template-columns: 1fr; gap: 2.5rem; }
  .photo-frame        { max-width: 260px; margin: 0 auto; }

  .projects-grid      { grid-template-columns: 1fr; }
  .proj-card.featured { flex-direction: column; }
  .proj-card.featured .proj-img { width: 100%; }

  .exp-card           { grid-template-columns: 1fr; }
  .exp-meta           { border-right: none; border-bottom: 1px solid var(--border); padding-right: 0; padding-bottom: 1rem; }
  /* ──  NAV ─────────────────────────────────── */
  header { 
    position: fixed;
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 300;
    padding: 0 0 env(safe-area-inset-bottom); 
    justify-content: stretch;
  }

  nav {
    width: 100%;
    border-radius: 20px 20px 0 0;
    border-bottom: none;
    padding: 0.5rem 0.4rem;
    background: rgba(9, 13, 26, 0.92);
  }

  body.light nav {
    background: rgba(244, 239, 228, 0.95);
  }

  nav ul {
    justify-content: space-around;
    width: 100%;
    gap: 0;
  }

  nav a {
    flex-direction: column;
    gap: 0.2rem;
    padding: 0.4rem 0.6rem;
    font-size: 0.6rem;
    border-radius: 10px;
    min-width: 48px;
    align-items: center;
  }

  nav a i {
    font-size: 1.1rem; 
  }

  nav a span {
    display: block; 
    font-size: 0.58rem;
    letter-spacing: 0.2px;
  }

  #theme-toggle {
    width: 40px;
    height: 40px;
    margin-left: 0;
  }

  /* contact grid stacks on mobile */
  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }
  .form-row     { grid-template-columns: 1fr; }
  .form-submit  { width: 100%; justify-content: center; }
}

@media (max-width: 420px) {
  nav a { padding: 0.35rem 0.4rem; min-width: 40px; }
  nav a span { display: none; } 
}

@media (max-width: 640px) {
.contact-grid { grid-template-columns: 1fr; gap: 2rem; }
.form-row     { grid-template-columns: 1fr; }
.form-submit  { width: 100%; justify-content: center; }
.coursework li { flex: 0 0 100%;}
}