/* ==========================================================================
   AETHERIX — common site footer
   --------------------------------------------------------------------------
   Shared by the showcase SPA (docs/index.html) and every generated lessons
   page (docs/lessons/*.html). Both surfaces define the same custom-property
   names, so this file needs no per-site overrides; the fallbacks after each
   var() keep it correct if it is ever dropped into a page that does not.

   The markup this expects lives in two places and must stay identical:
     * docs/index.html                      (hand-maintained)
     * scripts/generate_lessons_site.py     (SITE_FOOTER constant)
   ========================================================================== */

.site-footer {
  margin-top: 4rem;
  padding: 2.75rem 1.5rem 1.5rem;
  border-top: 1px solid var(--border, rgba(255, 255, 255, .08));
  background: linear-gradient(180deg,
              rgba(13, 21, 37, .35), rgba(5, 10, 20, .75));
  color: var(--text-secondary, #8892a4);
  font-size: .875rem;
  line-height: 1.7;
}

.site-footer a {
  color: var(--text-secondary, #8892a4);
  text-decoration: none;
  transition: color .15s;
}

.site-footer a:hover,
.site-footer a:focus-visible {
  color: var(--accent, #00d4ff);
  text-decoration: underline;
}

.site-footer-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(220px, 1.6fr) repeat(3, minmax(140px, 1fr));
  gap: 2rem;
  align-items: start;
}

/* --- brand block --------------------------------------------------------- */

.site-footer-brand-name {
  display: flex;
  align-items: center;
  gap: .55rem;
  font-weight: 900;
  letter-spacing: .06em;
  font-size: 1.05rem;
  color: var(--text-primary, #e4e8f0);
  margin-bottom: .5rem;
}

.site-footer-brand-name img { width: 22px; height: 22px; }

.site-footer-tagline {
  margin: 0 0 .9rem;
  max-width: 34ch;
  font-size: .82rem;
}

.site-footer-standards {
  margin: 0;
  font-size: .76rem;
  color: var(--text-muted, #5a6578);
}

.site-footer-standards code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
  color: var(--text-muted, #5a6578);
}

/* --- link columns -------------------------------------------------------- */

.site-footer-col h3 {
  margin: 0 0 .7rem;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent, #00d4ff);
}

.site-footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer-col li { margin: .3rem 0; }

/* --- bottom bar ---------------------------------------------------------- */

.site-footer-bottom {
  max-width: 1180px;
  margin: 2.25rem auto 0;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border, rgba(255, 255, 255, .08));
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.25rem;
  justify-content: space-between;
  align-items: center;
  font-size: .78rem;
  color: var(--text-muted, #5a6578);
}

.site-footer-bottom p { margin: 0; }

.site-footer-note {
  flex-basis: 100%;
  margin-top: .35rem !important;
  opacity: .85;
}

@media (max-width: 860px) {
  .site-footer-inner { grid-template-columns: repeat(2, minmax(140px, 1fr)); }
  .site-footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 480px) {
  .site-footer { padding: 2rem 1rem 1.25rem; }
  .site-footer-inner { grid-template-columns: 1fr; gap: 1.5rem; }
  .site-footer-bottom { justify-content: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  .site-footer a { transition: none; }
}