/* Pilot v7: manually measured page-by-page layout (18,19,21,22). */
#tca-answer-pilot-toggle {
  position:absolute; z-index:47;
  left:max(12px,env(safe-area-inset-left)); top:72px;
  display:inline-flex; align-items:center; justify-content:center; gap:7px;
  min-height:38px; padding:8px 12px; border-radius:999px;
  border:1px solid rgba(255,255,255,.25);
  background:linear-gradient(135deg,#0ea5a0,#0f766e 52%,#0c6060);
  color:#fff;box-shadow:0 10px 26px rgba(15,118,110,.28),inset 0 1px 0 rgba(255,255,255,.2);
  font:900 12px/1 system-ui,-apple-system,'Segoe UI',sans-serif;
  white-space:nowrap;cursor:pointer;touch-action:manipulation;
  transition:transform .15s ease,box-shadow .15s ease,filter .15s ease;
}
#tca-answer-pilot-toggle:hover:not(:disabled) {transform:translateY(-1px);filter:brightness(1.05)}
#tca-answer-pilot-toggle:focus-visible {outline:3px solid rgba(45,212,191,.55);outline-offset:3px}
#tca-answer-pilot-toggle svg {width:17px;height:17px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}
#tca-answer-pilot-message {position:absolute;z-index:47;top:115px;left:max(12px,env(safe-area-inset-left));
  width:min(385px,calc(100% - 24px));padding:7px 10px;background:rgba(15,23,42,.94);color:#fff;
  border:1px solid rgba(255,255,255,.19);border-radius:10px;font:650 11px/1.35 system-ui,sans-serif;
  box-shadow:0 8px 25px rgba(0,0,0,.16);pointer-events:none}
#tca-answer-pilot-message[hidden] {display:none!important}
#tca-answer-pilot-toggle:disabled {opacity:.88;background:#475569;border-color:#64748b;cursor:not-allowed;}
#tca-answer-pilot-toggle[data-answer-status="verified"] {background:linear-gradient(180deg,#087d70,#07534e);border-color:#13af9e;}
#tca-answer-pilot-toggle[aria-pressed="true"] {background:linear-gradient(180deg,#bb651a,#92400e);border-color:#fb923c;}
.tca-answer-pilot-overlay-v2 {position:absolute!important;inset:0!important;width:100%!important;height:100%!important;
  display:block!important;z-index:9!important;pointer-events:none!important;user-select:none!important;overflow:hidden!important;}
.tca-answer-pilot-overlay-v2 .tca-ap-answer {font-family:'Nunito','DejaVu Sans',Arial,sans-serif;font-weight:800;fill:#c62828;
  paint-order:stroke;stroke:#fff;stroke-width:.8;stroke-linejoin:round;}
.tca-answer-pilot-overlay-v2 .tca-ap-spot {fill-opacity:.18;stroke-width:3;}
.tca-answer-pilot-overlay-v2 .tca-ap-check {font-family:Arial,sans-serif;font-size:25px;font-weight:900;fill:#c62828;}
@media (max-width:760px){#tca-answer-pilot-toggle{min-height:34px;padding:6px 9px;font-size:11px;top:72px}#tca-answer-pilot-message{top:110px}}

/* Red, high contrast answer glyphs; no backgrounds hiding the page. */
.tca-answer-pilot-overlay-v2 .tca-ap-answer {fill:#c62828!important; stroke:rgba(255,255,255,.92)!important;stroke-width:.75px!important;font-weight:750!important;}
.tca-answer-pilot-overlay-v2 .tca-ap-check {fill:#c62828!important;}

/* v6: Classroom-native annotation style — not a big web badge. */
.tca-answer-pilot-overlay-v2 .tca-ap-answer {
 font-family:'Nunito',Arial,sans-serif!important;
 font-weight:700!important;
 fill:#b91c1c!important;
 stroke:rgba(255,255,255,.45)!important;
 stroke-width:.26px!important;
 paint-order:stroke;
 letter-spacing:0;
}

/* v15: Incompatible books never occupy screen with a status banner. */
#tca-answer-pilot-message{display:none!important;}

/* ATA UX18: unobtrusive forthcoming availability label beneath solution button. */
#tca-answer-pilot-coming-soon {
  position:absolute;z-index:47;top:115px;left:max(12px,env(safe-area-inset-left));
  box-sizing:border-box;width:145px;text-align:center;
  font:800 11px/1.25 system-ui,-apple-system,'Segoe UI',sans-serif;
  color:#f1f5f9;text-shadow:0 1px 3px rgba(0,0,0,.85);
  pointer-events:none;user-select:none;
}
#tca-answer-pilot-coming-soon[hidden]{display:none!important}
/* First-use warning: no third-party assets or library permissions. */
#tca-answer-experiment-backdrop {
  position:fixed;inset:0;z-index:2147483000;
  display:flex;align-items:center;justify-content:center;
  padding:20px;background:rgba(3,12,24,.69);backdrop-filter:blur(3px);
  box-sizing:border-box;
}
.tca-answer-experiment-dialog {
  width:min(100%,440px);box-sizing:border-box;border:1px solid rgba(148,163,184,.35);
  background:#f8fafc;color:#16283b;border-radius:19px;padding:27px 26px 24px;
  box-shadow:0 24px 65px rgba(0,0,0,.37);font-family:system-ui,-apple-system,'Segoe UI',sans-serif;
}
.tca-answer-experiment-symbol {display:inline-flex;align-items:center;justify-content:center;
  width:38px;height:38px;border-radius:12px;background:#ccfbf1;color:#0f766e;font-size:24px;font-weight:850;}
.tca-answer-experiment-dialog h2 {margin:14px 0 10px;color:#134e4a;font-size:20px;line-height:1.3;font-weight:800;}
.tca-answer-experiment-dialog p {font-size:14px;line-height:1.65;margin:0;color:#334155;}
.tca-answer-experiment-dialog p strong {font-weight:800;color:#0f172a;}
.tca-answer-experiment-actions {display:flex;justify-content:flex-end;gap:10px;flex-wrap:wrap;margin-top:23px;}
.tca-answer-experiment-actions button {border:1px solid #cbd5e1;border-radius:10px;cursor:pointer;
  padding:11px 14px;min-height:42px;font:750 13px/1.25 system-ui,sans-serif;}
.tca-answer-experiment-actions button[data-notice-action="ack"] {background:#0f766e;border-color:#0f766e;color:#fff;}
.tca-answer-experiment-actions button:focus-visible {outline:3px solid #14b8a6;outline-offset:2px;}
@media(max-width:760px){#tca-answer-pilot-coming-soon{top:112px;width:124px;font-size:10px}}
@media(max-width:430px){.tca-answer-experiment-dialog{padding:22px 17px}.tca-answer-experiment-actions{flex-direction:column}.tca-answer-experiment-actions button{width:100%}}