/* ============================================================
   RESPONSIVE — responsive.css
   ============================================================ */

/* ---- Large desktop: 1440px+ ---- */
@media (min-width: 1440px) {
  :root { --gutter: 4rem; }
}

/* ---- Tablet landscape: 1024px ---- */
@media (max-width: 1024px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }

  .professional-preview__grid { grid-template-columns: repeat(2, 1fr); }
  .approach-grid              { grid-template-columns: repeat(2, 1fr); }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
  .footer-brand { grid-column: 1 / -1; }
}

/* ---- Tablet: 768px ---- */
@media (max-width: 768px) {

  /* Nav */
  .primary-nav { display: none; }
  .nav-toggle  { display: flex; }

  .mobile-nav {
    position: fixed;
    top: 0; right: 0; bottom: 0;
    width: min(280px, 85vw);
    background: var(--color-bg-2);
    border-left: 1px solid var(--color-border-strong);
    z-index: calc(var(--z-nav) - 1);
    padding: calc(var(--header-height) + var(--space-8)) var(--space-8) var(--space-8);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform var(--duration-base) var(--ease-out);
    box-shadow: var(--shadow-lg);
  }

  .mobile-nav.is-open { transform: translateX(0); }

  .mobile-nav a {
    font-size: var(--text-lg);
    font-family: var(--font-display);
    font-weight: var(--weight-light);
    color: var(--color-ink-3);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-5) 0;
    border-bottom: 1px solid var(--color-border);
    transition: color var(--duration-fast) var(--ease-out);
  }

  .mobile-nav a::after {
    content: '→';
    font-family: var(--font-body);
    font-size: var(--text-xs);
    opacity: 0;
    transition: opacity var(--duration-fast) var(--ease-out);
  }

  .mobile-nav a:hover { color: var(--color-ink); }
  .mobile-nav a:hover::after { opacity: 1; }
  .mobile-nav a[aria-current="page"] { color: var(--color-accent); }

  /* Grids */
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .editorial-grid,
  .editorial-grid--wide      { grid-template-columns: 1fr; }

  /* Home sections */
  .projects-grid               { grid-template-columns: 1fr; }
  .approach-grid               { grid-template-columns: 1fr; }
  .professional-preview__grid  { grid-template-columns: 1fr; }
  .intro-stats                 { grid-template-columns: 1fr 1fr; }
  .intro-section__top          { flex-direction: column; align-items: flex-start; gap: var(--space-3); }
  .intro-section__body         { grid-template-columns: 1fr; gap: var(--space-6); }
  .research-section__inner     { grid-template-columns: 1fr; }
  .approach-section__inner     { grid-template-columns: 1fr; gap: var(--space-8); }
  .approach-section__label     { position: static; }

  /* Project detail */
  .project-intro__grid  { grid-template-columns: 1fr; }
  .project-hero__image  { aspect-ratio: 4 / 3; }
  .plans-grid           { grid-template-columns: 1fr; }

  /* About */
  .about-hero__grid     { grid-template-columns: 1fr; }
  .skills-grid          { grid-template-columns: 1fr 1fr; }
  .education-item {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }

  /* Contact */
  .contact-grid           { grid-template-columns: 1fr; }
  .contact-form .form-row { grid-template-columns: 1fr; }

  /* Projects listing */
  .projects-listing-grid  { grid-template-columns: 1fr; }

  /* Professional works */
  .pw-project__images     { grid-template-columns: 1fr; }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
  .footer-brand { grid-column: auto; }

  /* Project nav */
  .project-nav { grid-template-columns: 1fr; }

  /* Meta table */
  .meta-table {
    grid-template-columns: 1fr;
    gap: var(--space-1);
  }
  .meta-table dt { margin-top: var(--space-3); }

  /* IBH chess + zoning rows */
  .chess-row-grid { grid-template-columns: repeat(2, 1fr) !important; }
  .zoning-grid    { grid-template-columns: repeat(2, 1fr) !important; }

  /* Gallery */
  .gallery-grid { grid-template-columns: repeat(2, 1fr); }

  /* Lightbox */
  .lightbox__img {
    max-width: 95vw;
    max-height: 80vh;
  }
}

/* ---- Mobile: 480px ---- */
@media (max-width: 480px) {
  :root { --gutter: 1.25rem; }

  h1 { font-size: var(--text-3xl); }
  h2 { font-size: var(--text-2xl); }

  .hero__name  { font-size: clamp(2.5rem, 12vw, 4rem); }

  .hero__bottom > div:last-child { display: none; }

  .intro-stats             { grid-template-columns: 1fr 1fr; }
  .skills-grid             { grid-template-columns: 1fr; }
  .professional-preview__grid { grid-template-columns: 1fr; }
  .gallery-grid            { grid-template-columns: 1fr; }

  .chess-row-grid { grid-template-columns: 1fr !important; }
  .zoning-grid    { grid-template-columns: repeat(2, 1fr) !important; }

  .pub-card                { flex-direction: column; }
  .filter-bar              { gap: var(--space-2); }

  .cta-band .btn-group {
    flex-direction: column;
    align-items: center;
  }

  .project-hero__caption h1 { font-size: var(--text-2xl); }

  .footer-grid             { grid-template-columns: 1fr; }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .section-header.flex-between {
    flex-direction: column;
    align-items: flex-start;
  }

  .lightbox__close {
    top: -48px;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
}

/* ---- Very small: 360px ---- */
@media (max-width: 360px) {
  .btn { padding: var(--space-3) var(--space-5); font-size: var(--text-xs); }
  .filter-btn { padding: var(--space-2) var(--space-3); }
  .chess-row-grid { grid-template-columns: 1fr !important; }
  .zoning-grid    { grid-template-columns: 1fr !important; }
  .project-row { grid-template-columns: 36px 1fr; gap: var(--space-3); }
  .meta-table { font-size: var(--text-xs); }
  .pw-project__images img { aspect-ratio: 3 / 2; }
  /* Hero: prevent any overflow on very narrow screens */
  .hero__content { padding-inline: var(--space-4); }
  .hero__name { font-size: clamp(1.75rem, 10vw, 2.5rem); line-height: 1; }
  .hero__portrait { opacity: 0.35; }
}