/* ============================================================
   Systems Super-Shell — Phase 4 companion styles (Group A)
   Scoped under #systems-root. Pairs with systems-shell.js.
   Tab strip mirrors the Journaling .j-tabs pattern but uses the
   Systems page accent (var(--accent)), not gold.
   ============================================================ */

/* ---- controls: header button row + sticky tab strip ---- */
#systems-root .sysx-controls {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 14px 0 24px;
}
#systems-root .sysx-headbar {
  display: flex;
  justify-content: flex-end;
}

#systems-root .sysx-tabs {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  gap: 4px;
  padding: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  background: var(--topbar-bg, var(--surface));
  backdrop-filter: blur(14px);
  border: 1px solid var(--line);
  border-radius: 14px;
}
#systems-root .sysx-tabs::-webkit-scrollbar { display: none; }

#systems-root .sysx-tab {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 9px 15px;
  border-radius: 9px;
  font-family: var(--sans);
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  background: transparent;
  border: 1px solid transparent;
  white-space: nowrap;
  cursor: pointer;
  transition: color .15s, background .15s, border-color .15s;
}
#systems-root .sysx-tab:hover { color: var(--text); background: var(--surface-2); }
#systems-root .sysx-tab.active {
  color: var(--text);
  background: var(--surface-2);
  border-color: var(--accent);
}

/* ---- panels: one visible at a time ---- */
#systems-root .sysx-panel { display: none; }
#systems-root .sysx-panel.active {
  display: block;
  animation: sysxFade .25s var(--ease, ease);
}
#systems-root .sysx-panel > section:first-child { margin-top: 0; }
@keyframes sysxFade {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: none; }
}

/* ---- in-page overlays (Reference & Theory / Backup & Restore) ---- */
/* fixed modal, but still a DOM descendant of #systems-root so the
   scoped CSS + already-wired handlers on the moved nodes keep working */
#systems-root .sysx-overlay {
  position: fixed;
  inset: 0;
  z-index: 120;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: 40px 16px;
  overflow-y: auto;
  background: rgba(0, 0, 0, .62);
  backdrop-filter: blur(6px);
}
#systems-root .sysx-overlay.open { display: flex; }
#systems-root .sysx-overlay-card {
  width: min(960px, 100%);
  margin: auto 0;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 30px 80px rgba(0, 0, 0, .5);
  animation: sysxPop .25s var(--ease, ease);
}
@keyframes sysxPop {
  from { opacity: 0; transform: translateY(10px) scale(.99); }
  to   { opacity: 1; transform: none; }
}
#systems-root .sysx-overlay-head {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 22px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  border-radius: 18px 18px 0 0;
  z-index: 2;
}
#systems-root .sysx-overlay-head h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  color: var(--text);
}
#systems-root .sysx-overlay-close {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 9px;
  cursor: pointer;
  background: var(--surface-2);
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 15px;
  line-height: 1;
  transition: color .15s, border-color .15s;
}
#systems-root .sysx-overlay-close:hover { color: var(--text); border-color: var(--accent); }
#systems-root .sysx-overlay-body { padding: 22px; }
/* the moved #theory keeps its own accordions but the overlay head
   already titles it, so hide its in-section header */
#systems-root .sysx-overlay-body > #theory { margin: 0; }
#systems-root .sysx-overlay-body > #theory > .sec-head { display: none; }

/* ---- mobile ---- */
@media (max-width: 640px) {
  #systems-root .sysx-headbar { justify-content: stretch; }
  #systems-root .sysx-overlay { padding: 0; }
  #systems-root .sysx-overlay-card { width: 100%; min-height: 100%; border-radius: 0; }
  #systems-root .sysx-overlay-head { border-radius: 0; }
}