*{
  margin:0;
  padding:0;
  box-sizing:border-box;
  font-family:Arial, sans-serif;
}

body{
  background:#f4f4f4;
  color:#222;
  display:flex;
  justify-content:center;
  align-items:center;
  min-height:100vh;
  padding:20px;
}

.caja{
  width:100%;
  max-width:900px;
  background:white;
  border-radius:20px;
  padding:30px;
  box-shadow:0 4px 10px rgba(0,0,0,0.1);
  text-align:center;
}

.titulo{
  font-size:32px;
  margin-bottom:25px;
}

/* CONTENEDOR DEL VIDEO */
.video-contenedor {
  position: relative;
  padding-bottom: 56.25%; /* Relación de aspecto 16:9 */
  height: 0;
  overflow: hidden;
  max-width: 100%;
  background: #000; /* Si ves un fondo negro, el iframe está cargando pero el video no */
  border-radius: 15px;
}

.video-contenedor iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* BOTÓN VOLVER */
.boton-volver{
  display:inline-block;
  text-decoration:none;
  background:#222;
  color:white;
  padding:14px 22px;
  border-radius:12px;
  transition:0.2s;
  font-size:16px;
}

.boton-volver:hover{
  background:#444;
  transform:scale(1.03);
}

.descripcion{
  margin-bottom:20px;
  color:#666;
}