html,
body {
  width: 100%;
  height: 100%;
  min-height: 100%;
  margin: 0 !important;
  padding: 0 !important;
  overflow: hidden !important;
  background: #000 !important;
}

/* Esconde qualquer conteúdo, cabeçalho ou rodapé do tema */
header,
footer,
#site-header,
#site-footer,
.lb-slot--header,
.lb-slot--footer {
  display: none !important;
}

.under-construction-video {
  position: fixed;
  inset: 0;
  z-index: 999999;
  width: 100vw;
  height: 100vh;
  height: 100svh;
  height: 100dvh;
  overflow: hidden;
  background: #000;
}

.under-construction-video video {
  display: block;
  width: 100%;
  height: 100%;
  min-width: 100%;
  min-height: 100%;
  object-fit: cover;
  object-position: center;
  border: 0;
  outline: 0;
  pointer-events: none;
}

/* Ajuste específico para celulares */
@media (max-width: 767px) {
  .under-construction-video video {
    object-position: center center;
  }
}


<div class="under-construction-video">
  <video autoplay muted loop playsinline preload="auto" aria-label="Vídeo de apresentação">
    
  </video>
</div>