/* RED20 PWA Shell v71 - top floating Back button, no page menu links */
:root{
  --red20-pwa-blue:#2563eb;
  --red20-pwa-blue2:#1d4ed8;
  --red20-pwa-card:rgba(15,23,42,.94);
  --red20-pwa-line:rgba(148,163,184,.30);
}
.red20-pwa-shell,.red20-pwa-shell *{box-sizing:border-box}
.red20-pwa-shell{position:fixed;left:8px;top:calc(env(safe-area-inset-top,0px) + 8px);right:auto;bottom:auto;z-index:2147482400;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial;display:flex;align-items:flex-start;gap:10px;pointer-events:none}
.red20-pwa-actions{display:flex;gap:8px;align-items:center;pointer-events:auto}
.red20-pwa-btn{border:1px solid var(--red20-pwa-line);background:linear-gradient(135deg,var(--red20-pwa-blue),var(--red20-pwa-blue2));color:#fff;border-radius:999px;min-height:31px;padding:6px 9px;font-size:11px;font-weight:950;box-shadow:0 10px 24px rgba(37,99,235,.18);cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;gap:6px;line-height:1;white-space:nowrap;opacity:.72;backdrop-filter:blur(14px)}
.red20-pwa-btn:hover{filter:brightness(1.06);opacity:1}
.red20-pwa-btn:active{transform:scale(.98)}
.red20-pwa-btn.secondary{background:var(--red20-pwa-card);backdrop-filter:blur(14px);box-shadow:0 12px 32px rgba(0,0,0,.26)}
.red20-pwa-toast{position:fixed;left:12px;right:12px;bottom:72px;z-index:2147482600;display:flex;justify-content:center;pointer-events:none}.red20-pwa-toast>div{max-width:520px;border-radius:16px;background:rgba(15,23,42,.97);border:1px solid rgba(148,163,184,.28);color:#e5e7eb;padding:10px 13px;box-shadow:0 18px 50px rgba(0,0,0,.42);font-size:13px;font-weight:900;line-height:1.35}
@media(max-width:580px){.red20-pwa-shell{left:6px;top:calc(env(safe-area-inset-top,0px) + 6px)}.red20-pwa-btn{min-height:30px;padding:6px 8px;font-size:10.5px}.red20-pwa-btn span{display:none}}
@media print{.red20-pwa-shell,.red20-pwa-toast{display:none!important}}