/* =============================================================
   CoMPhy Lab · Footer v2
   Paper-tinted, NOT a dark slab. Four-column layout: brand blurb,
   Explore, Work with us, Code & data. Partner marks on paper tint
   with .invert-on-light for white-PNG assets. Silent legal strip.
   Red Team Audit A2.
   ============================================================= */

.c-footer {
  background: var(--c-paper-tint);
  border-top: 1px solid var(--c-border);
  padding: var(--s-8) 0 var(--s-6);
  margin-top: var(--s-9);
  color: var(--fg-1);
  position: relative;
  z-index: 1;
}

.c-footer__wrap {
  width: min(100% - 2rem, var(--maxw-page));
  margin: 0 auto;
}

.c-footer__top {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: var(--s-6);
  padding-bottom: var(--s-6);
  border-bottom: 1px solid var(--c-border);
}

.c-footer__brand { display: grid; gap: var(--s-3); align-content: start; }

.c-footer__mark {
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
  font-family: var(--t-display);
  font-style: italic;
  font-weight: 500;
  font-size: 22px;
  color: var(--fg-strong);
  text-decoration: none;
  border-bottom: 0;
}

.c-footer__mark:hover { color: var(--c-accent-teal); }

.c-footer__mark img { height: 56px; width: auto; }

.c-footer__tag {
  font-family: var(--t-serif);
  font-size: 14px;
  color: var(--fg-2);
  line-height: 1.5;
  max-width: 36ch;
  font-variation-settings: "opsz" 14;
  margin: 0;
}

.c-footer__col h4 {
  font-family: var(--t-sans);
  font-size: var(--t-eyebrow);
  font-weight: 600;
  letter-spacing: var(--t-track-wide);
  text-transform: uppercase;
  color: var(--fg-2);
  margin: 0 0 var(--s-3);
}

.c-footer__col a {
  display: block;
  font-size: 13px;
  padding: 3px 0;
  color: var(--fg-1);
  border-bottom: 0;
  text-decoration: none;
}

.c-footer__col a:hover { color: var(--c-accent-teal); }

/* --- Partner strip ----------------------------------------- */
.c-footer__partners {
  padding-top: var(--s-5);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--s-5);
}

.c-footer__partners-label {
  font-family: var(--t-sans);
  font-size: var(--t-eyebrow);
  font-weight: 600;
  letter-spacing: var(--t-track-wide);
  text-transform: uppercase;
  color: var(--fg-2);
}

.c-footer__partners-logos {
  display: flex;
  align-items: center;
  gap: var(--s-7);
  flex-wrap: wrap;
}

.c-footer__partners-logos a {
  display: inline-flex;
  align-items: center;
  border-bottom: 0;
  opacity: 0.75;
  transition: opacity var(--dur-fast) var(--ease);
}

.c-footer__partners-logos a:hover { opacity: 1; }

.c-footer__partners-logos img {
  height: 72px;
  width: auto;
  display: block;
}

/* Durham: two discrete assets swap by theme. */
.c-footer__partners-logos .logo-dark-only { display: none; }

:root[data-theme="dark"] .c-footer__partners-logos .logo-light-only { display: none; }

:root[data-theme="dark"] .c-footer__partners-logos .logo-dark-only { display: block; }

/* --- Legal strip ------------------------------------------- */
.c-footer__legal {
  margin-top: var(--s-6);
  padding-top: var(--s-5);
  border-top: 1px solid var(--c-border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--s-4);
  font-size: 12px;
  color: var(--fg-2);
}

.c-footer__legal a {
  color: var(--fg-2);
  border-bottom: 1px solid var(--c-border-strong);
  text-decoration: none;
}

.c-footer__legal a:hover {
  color: var(--c-accent-teal);
  border-bottom-color: var(--c-accent-teal);
}

/* --- Responsive -------------------------------------------- */
@media (max-width: 820px) {
  .c-footer__top { grid-template-columns: 1fr 1fr; }

  .c-footer__partners { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 520px) {
  .c-footer__top { grid-template-columns: 1fr; }

  .c-footer__partners-logos { gap: var(--s-5); }
}

/* --- Neutralise legacy .site-footer positional rules ------- */
/* styles.css still has rules for .site-footer that position the
   three-column layout. Our v2 footer uses grid via .c-footer__top,
   so undo the flex/positional bits that would otherwise leak. */
footer.site-footer .footer-left,
footer.site-footer .footer-right,
footer.site-footer .footer-center,
footer.site-footer .ss-go-top { display: none; }