html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  background: #F7F7F7;
  font-family: Arial, sans-serif;
  overflow: hidden; /* Impede qualquer rolagem */
}

/* Header fixo no topo */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 90px;
  background-color: #F7F7F7;
  display: flex;
  justify-content: left;
  align-items: center;
  z-index: 1000;
}

header img {
  height: 100%;
}

/* Container do vídeo */
.video-wrapper {
  position: absolute;
  top: 90px; /* mesma altura da header */
  left: 0;
  width: 100%;
  height: calc(100vh - 60px);
  overflow: hidden;
  z-index: 1;
  background: #F7F7F7;
}

.video-wrapper video {
  object-fit: cover;
  width: 100%;
  height: auto;
  display: block;
}

/* Botão de som fixo */
.botao-som {
  padding: 0 15px;
  cursor: pointer;
  position: absolute;
  top: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  opacity: 0.3;
  border-radius: 10px;
  z-index: 9999;
  background: white;
  justify-content: center;
  align-items: center;
  display: flex;
  border: 1px solid black;
}

/* Responsivo para mobile */
@media (max-width: 580px) {
  header {
    height: 50px;
  }

  header img {
    height: 40px;
  }

  .video-wrapper {
    top: 50px; /* altura do header mobile */
    height: calc(100vh - 50px);
  }

  .botao-som {
    top: auto;
    bottom: 20px;
    right: 10px;
    width: 45px;
    height: 45px;
  }
}