:root { --bmcm-opacity: .75; --bmcm-fade: 400ms; }
.bmcm-shade { position: fixed; background: rgba(0,0,0,var(--bmcm-opacity)); z-index: 2147483000; opacity: 0; pointer-events: none; transition: opacity var(--bmcm-fade) ease; box-sizing: border-box; }
body.bmcm-active .bmcm-shade { opacity: 1; pointer-events: auto; }
@media (prefers-reduced-motion: reduce) { .bmcm-shade { transition-duration: 0ms; } }