/* ============================================================
   Owente Kellen — Portfolio
   responsive.css — breakpoint overrides (mobile-first content,
   desktop-first grid collapsing since base styles target desktop)
   ============================================================ */

/* ---- Tablet: tighten grids ------------------------------------------- */
@media (max-width: 1080px) {
  .expertise__grid,
  .publications__grid,
  .social__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .about__aside {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .about__aside .credential-card {
    flex: 1 1 240px;
  }
}

/* ---- Nav collapses to hamburger --------------------------------------- */
@media (max-width: 900px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav__links {
    position: fixed;
    inset-inline: 0;
    top: var(--nav-height);
    bottom: 0;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 0.25rem;
    background: var(--ink-2);
    padding: 1.5rem var(--gutter) 2.5rem;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease), visibility var(--dur-fast);
    overflow-y: auto;
  }

  .site-nav__links.is-open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
  }

  .site-nav__links a:not(.btn) {
    width: 100%;
    padding-block: 0.9rem;
    font-size: 0.95rem;
    color: var(--paper-on-ink);
    border-bottom: 1px solid var(--rule-on-ink);
  }

  .site-nav__links a:not(.btn)::after {
    display: none;
  }

  .site-nav__cta {
    margin-top: 1.25rem;
    margin-left: 0;
  }
}

/* ---- Hero & major sections stack --------------------------------------- */
@media (max-width: 860px) {
  .hero__row {
    grid-template-columns: 1fr;
    text-align: left;
  }

  .hero__portrait {
    order: -1;
    margin-bottom: 1rem;
  }

  .seal {
    width: min(200px, 45vw);
  }

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

/* ---- Small tablet / large phone --------------------------------------- */
@media (max-width: 700px) {
  .expertise__grid,
  .publications__grid,
  .social__grid {
    grid-template-columns: 1fr;
  }

  .featured-pub {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
  }

  .journey-item--education {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
  }

  .site-footer__row {
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
  }

  .site-footer__links {
    gap: 1.25rem;
  }
}

/* ---- Phones ------------------------------------------------------------ */
@media (max-width: 480px) {
  :root {
    --nav-height: 72px;
  }

  .hero__name {
    font-size: clamp(2.6rem, 12vw, 3.4rem);
  }

  .hero__actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero__actions .btn {
    justify-content: center;
  }

  .about__aside {
    flex-direction: column;
  }

  .contact__card {
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
  }

  .to-top {
    right: 1rem;
    bottom: 1rem;
    width: 42px;
    height: 42px;
  }
}