@media (max-width: 720px) {
  .container { width: calc(100% - 2rem); }

  .site-header { position: static; }

  .nav-shell {
    flex-wrap: wrap;
    gap: 0.35rem 1rem;
    min-height: 0;
    padding: 0.7rem 0;
  }

  .nav-links {
    order: 3;
    width: 100%;
    gap: 0.1rem 0.9rem;
    font-size: 0.9rem;
  }

  .nav-cta { display: none; }

  .hero { padding: 2.5rem 0 2.25rem; }

  section { padding: 2rem 0; }

  .cta-row .btn { flex: 1 1 auto; }

  .cta-row .aside-links {
    width: 100%;
    margin-left: 0;
  }

  .sheet,
  .sheet--wide {
    grid-template-columns: 1fr;
    row-gap: 0.9rem;
  }

  .sheet dt { margin-bottom: -0.65rem; }

  .habits { grid-template-columns: 1fr; }

  .cert-list li {
    grid-template-columns: 1fr auto;
    row-gap: 0.1rem;
  }

  .cert-name { grid-column: 1; }

  .cert-link {
    grid-column: 2;
    grid-row: 1 / span 2;
    align-self: center;
  }

  .cert-issuer { grid-column: 1; }

  .cert-year { display: none; }

  .cert-issuer::after { content: ", " attr(data-year); }

  .footer-shell {
    flex-direction: column;
    align-items: flex-start;
  }
}