* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}



.p-t-b-15 {
  padding-top: 15px;
  padding-bottom: 15px;
  position: relative;
  z-index: 100;
}

.container { /* Corregido: "contanier" a "container" */
  height: 100vh;
  width: 100%; /* Corregido: "widht" a "width" */
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.overlay {
  background-color: rgba(0, 0, 0, 0);
  height: 100%;
  width: 100%;
  position: absolute;
  top: 0;
  left: 0;
  z-index: 10;
}

@keyframes fade {
  0% {
    opacity: 1;
  }

  33% {
    opacity: 0;
  }

  67% {
    opacity: 0;
  }

  100% {
    opacity: 1;
  }
}

img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  top: 0;
  left: 0;
  animation: fade 9s ease-in-out infinite alternate;
}

/* Corregido: espacio en "nth-of-type" */
img:nth-of-type(1) {
  animation-delay: 0s;
}

img:nth-of-type(2) {
  animation-delay: 3s;
}

img:nth-of-type(3) {
  animation-delay: 6s;
}

.heading {
  font-size: 50px;
  color: #fff;
  position: relative;
  z-index: 100;
}