.container {
  margin: 150px auto;
  max-width: 1200px;
}

.container>h1 {
  padding: 3rem 0;
  font-size: 3rem;
  text-align: center;
}

.container>h2 {
  padding: 2rem 0;
  font-size: 2rem;
  text-align: center;
}

#slider article {
  height: 30rem;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: sans-serif;
}

.slide-left, .slide-right {
  top: 14rem;
  padding: 0.5rem 1rem;
  font-family: sans-serif;
  font-size: 2rem;
  cursor: pointer;
  color: white;
  background-color: rgba(0, 0, 0, 0.25);
}

.slide-left { left: 1rem; }

.slide-right { right: 1rem; }

#slider article h1 {
  font-size: 2rem;
  text-align: center;
}

#slider article p { text-align: center; }

#slider article:nth-of-type(1) {
  color: white;
  background-color: #333333;
}

#slider article:nth-of-type(2) {
  color: white;
  background: linear-gradient(to bottom, rgba(0,0,0,0.5), rgba(0,0,0,0.5)), url('https://picsum.photos/1200/675?image=777');
  background-position:50% 50%;
  background-size:cover;
}

#slider article:nth-of-type(3) {
  position: relative;
  color: black;
  overflow: hidden;
}

#slider article:nth-of-type(3) div { z-index: 2; }

#slider article:nth-of-type(3) video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
}