/* ═══════════════════════════════════════════════════════════
   bts-frame — Behind-the-Scenes / Concept Explainer frame

   Use this for any UI that is NOT what the user sees. Never
   mix with a device frame (iPhone, iPad, CarPlay). The chip at
   top-left declares what kind of UI this is.

   Usage (unified chip terminology — 2026-04-23):
     BACKSTAGE = the single word we use to say "AI is working, user does not see this".
     CONCEPT   = designer/reader explainer, not an AI view.

     <div class="bts-frame" data-kind="concept">
       <div class="bts-frame__chip">CONCEPT · [topic]</div>
       <div class="bts-frame__body">…</div>
     </div>

     <div class="bts-frame bts-frame--dark" data-kind="backstage">
       <div class="bts-frame__chip">BACKSTAGE · [topic]</div>
       <div class="bts-frame__body">…</div>
     </div>

   Rules:
   - Thin dashed border + subtle bg
   - Top-left chip always present
   - Dark variant for AI-internals views
   - Never wraps a device frame
   ─────────────────────────────────────────────────────────── */

.bts-frame {
  position: relative;
  background: var(--bg, #fff);
  border: 1.5px dashed var(--border-strong, rgba(0, 0, 0, 0.18));
  border-radius: 12px;
  padding: 44px 28px 28px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.bts-frame__chip {
  position: absolute;
  top: 12px;
  left: 16px;
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-2, #525252);
  padding: 6px 12px;
  background: var(--bg, #fff);
  border: 1px solid var(--border, rgba(0, 0, 0, 0.12));
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.bts-frame__chip::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--text-2, #525252);
  opacity: 0.6;
}
.bts-frame[data-kind="concept"]   .bts-frame__chip::before { background: var(--amber, #c2410c); opacity: 0.7; }
.bts-frame[data-kind="backstage"] .bts-frame__chip::before { background: var(--color-brain, #8a6ab0); opacity: 0.85; }
/* Legacy alias: data-kind="behind" still works but BACKSTAGE is the canonical term */
.bts-frame[data-kind="behind"]    .bts-frame__chip::before { background: var(--color-brain, #8a6ab0); opacity: 0.85; }

.bts-frame__body {
  position: relative;
}

/* Optional: subtitle row right below the chip */
.bts-frame__note {
  position: absolute;
  top: 20px;
  right: 20px;
  font-family: var(--font-mono, ui-monospace, monospace);
  font-size: 10px;
  letter-spacing: 0.6px;
  color: var(--text-2, #525252);
  font-weight: 500;
  max-width: 60%;
  text-align: right;
  line-height: 1.4;
}

/* ═══ Dark variant — for Behind-the-Scenes AI internals ═══ */
.bts-frame--dark {
  background: #0d0c10;
  border-color: rgba(240, 236, 228, 0.14);
  color: #e8dfd0;
  box-shadow: inset 0 0 0 1px rgba(240, 236, 228, 0.02),
              0 24px 56px rgba(0, 0, 0, 0.12);
}
.bts-frame--dark .bts-frame__chip {
  background: #14131a;
  border-color: rgba(240, 236, 228, 0.12);
  color: rgba(240, 236, 228, 0.75);
}
.bts-frame--dark .bts-frame__note {
  color: rgba(240, 236, 228, 0.45);
}

/* ═══ Floating variant — no border, just a shadow-floated panel ═══ */
.bts-frame--floating {
  border: 0;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04),
              0 24px 56px rgba(0, 0, 0, 0.08),
              inset 0 0 0 1px rgba(0, 0, 0, 0.04);
}
.bts-frame--floating.bts-frame--dark {
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.3),
              0 32px 64px rgba(0, 0, 0, 0.35),
              inset 0 0 0 1px rgba(240, 236, 228, 0.04);
}

/* ═══ Responsive ═══ */
@media (max-width: 768px) {
  .bts-frame { padding: 44px 18px 20px; }
  .bts-frame__chip { font-size: 9px; padding: 5px 10px; left: 12px; top: 10px; }
  .bts-frame__note {
    position: static;
    margin-top: 6px;
    text-align: left;
    max-width: 100%;
  }
}