/* Escher — the periodic drawings arranged by wallpaper group and colour
   group.  Shares the visual language of patterns.css (light, big sans family
   headings, teal accent, colour-group tabs); the leaf content is drawing
   cards rather than pattern-type panes. */

.escher-note {
  margin: 1rem 0 0;
  padding: 0.7rem 0.95rem;
  border-left: 3px solid var(--pattern-accent);
  background: var(--pattern-soft);
  border-radius: 0 0.4rem 0.4rem 0;
  font-size: 0.88rem;
  line-height: 1.5;
  color: #33403c;
}
.escher-note strong { color: var(--pattern-accent); }

/* ---------------------------------------------------------- group panel */
.escher-band { padding: 0 clamp(1rem, 2vw, 1.6rem) clamp(1rem, 2vw, 1.5rem); }
.escher-band-intro {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(16rem, 22rem);
  gap: clamp(1rem, 2vw, 2rem);
  align-items: start;
  padding: clamp(0.8rem, 1.6vw, 1.2rem) 0 0.9rem;
}
.escher-band-facts { min-width: 0; }
.escher-plate { margin: 0; min-width: 0; }
.escher-plate svg {
  display: block; width: 100%; height: auto; aspect-ratio: 12 / 7;
  border: 1px solid #cdd8d3; background: #f8f7f1; border-radius: 0.3rem;
}
.escher-plate figcaption {
  font-size: 0.72rem; color: var(--pattern-muted); margin-top: 0.3rem;
}

/* ---------------------------------------------------------- drawing grid */
.drawing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr));
  gap: 0.8rem;
  margin: 0.2rem 0 0;
  padding: 0;
  list-style: none;
}
.drawing-card {
  display: flex; flex-direction: column; gap: 0.3rem; min-width: 0;
  padding: 0.7rem 0.8rem 0.75rem;
  border: 1px solid var(--pattern-rule);
  border-radius: 0.55rem;
  background: #fff;
  transition: box-shadow 120ms ease, border-color 120ms ease, transform 120ms ease;
}
.drawing-card:hover, .drawing-card:focus-within {
  border-color: #7fa79b;
  box-shadow: 0 6px 18px rgba(0, 118, 107, 0.13);
  transform: translateY(-1px);
}
.drawing-head { display: flex; align-items: baseline; gap: 0.45rem; flex-wrap: wrap; }
.drawing-number {
  flex: 0 0 auto;
  font: 700 0.72rem/1 ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  letter-spacing: 0.02em;
  color: #fff; background: var(--pattern-accent);
  border-radius: 999px; padding: 0.2rem 0.45rem;
}
.drawing-title {
  font: 700 1rem/1.2 ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--pattern-ink);
  overflow-wrap: anywhere;
}
.drawing-title a { text-decoration-color: #9fb8b0; }
.drawing-meta { font-size: 0.78rem; color: var(--pattern-muted); line-height: 1.45; }
.drawing-meta .sep { color: #b3c0bb; padding: 0 0.15rem; }
.drawing-source { font-size: 0.7rem; color: #7d8b86; }
.drawing-source a { color: #40706a; }
/* thumbnail slot: only rendered when a local image is present (see the note
   on rights in escher.html) */
.drawing-thumb {
  display: block; width: 100%; height: auto; aspect-ratio: 4 / 3;
  object-fit: cover; border: 1px solid var(--pattern-rule);
  border-radius: 0.35rem; background: var(--pattern-soft);
}
.drawing-card.is-linkonly .drawing-thumb-placeholder {
  display: grid; place-items: center;
  aspect-ratio: 4 / 3;
  border: 1px dashed var(--pattern-rule); border-radius: 0.35rem;
  background: repeating-linear-gradient(135deg, #f7faf8, #f7faf8 8px, #f1f6f3 8px, #f1f6f3 16px);
  color: #8c9a95; font-size: 0.74rem; text-align: center; padding: 0.5rem;
}
.confidence-flag {
  font: 650 0.68rem/1 ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--pattern-seat); background: #fde8e2;
  border-radius: 0.2rem; padding: 0.12rem 0.3rem;
  box-shadow: 0 0 0 1px #f2c3b7;
}

/* colour-group tabs get a drawing count badge */
.tab-count {
  font: 650 0.68rem/1 ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--pattern-accent);
}
.colour-group-tab.is-empty { opacity: 0.4; }
.colour-group-tab.is-empty:hover { opacity: 0.75; }

.empty-note {
  margin: 0.4rem 0 0; font-size: 0.85rem; color: var(--pattern-muted);
}

@media (max-width: 900px) {
  .escher-band-intro { grid-template-columns: 1fr; }
}