@media (max-width: 980px) {
  .split-layout,
  .footer-grid,
  .cta-card {
    grid-template-columns: 1fr;
  }

  .card-grid--three,
  .module-grid,
  .capability-grid,
  .capability-grid--wide,
  .platform-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

}

@media (max-width: 820px) {
  :root {
    --header-height: 68px;
  }

  .mobile-toggle {
    display: inline-grid;
    place-items: center;
  }

  .nav-menu {
    position: fixed;
    inset: var(--header-height) 1rem auto 1rem;
    display: grid;
    gap: 0.3rem;
    padding: 1rem;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: var(--surface);
    box-shadow: var(--shadow-md);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 180ms ease, transform 180ms ease;
  }

  body.is-menu-open .nav-menu {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-menu a {
    padding: 0.85rem 1rem;
  }

  .nav-menu__mobile-only {
    display: block;
  }

  .brand__tagline {
    display: none;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 1.2rem, var(--max));
  }

  .section {
    padding: 3.15rem 0;
  }

  .section + .section {
    padding-top: 1.75rem;
  }

  .section--first {
    padding-top: calc(var(--header-height) + 2.75rem);
    padding-bottom: 2.85rem;
  }

  .card-grid--three,
  .module-grid,
  .capability-grid,
  .capability-grid--wide,
  .product-panel__grid,
  .platform-grid,
  .footer-links {
    grid-template-columns: 1fr;
  }

  .hero__actions,
  .page-hero__actions,
  .cta-card .button {
    width: 100%;
  }

  .button {
    width: 100%;
  }

  .nav-actions .button {
    display: none;
  }

  .language-select {
    max-width: 5.8rem;
  }

  .brand__mark {
    width: 2.45rem;
    height: 2.45rem;
  }

  .hero__title {
    max-width: 100%;
    font-size: clamp(2.25rem, 11vw, 3.65rem);
  }

  .hero__content--centered .hero__meta {
    justify-content: center;
  }

  .hero-card,
  .product-panel,
  .feature-card,
  .module-card,
  .portfolio-card,
  .tool-card,
  .note-card,
  .tech-panel,
  .orcid-card,
  .identity-card,
  .contact-form,
  .stack-list,
  .problem-list,
  .check-list--panel {
    border-radius: var(--radius-md);
  }
}


@media (max-width: 640px) {
  .projects-sections,
  .projects-browser {
    gap: 2.15rem;
  }

  .project-filter-bar {
    gap: 0.5rem;
  }

  .project-filter-button {
    flex: 1 1 auto;
  }

  .project-card {
    border-radius: var(--radius-md);
  }

  .project-card__actions {
    grid-template-columns: 1fr;
  }

  .project-card__title {
    font-size: clamp(1.55rem, 9vw, 2.25rem);
  }
}