.hero {
  background: linear-gradient(rgba(0, 0, 0, .6), rgba(0, 0, 0, .6)), url("https://images.unsplash.com/photo-1524995997946-a1c2e315a42f");
  background-size: cover;
  background-position: center;
  color: white;
  padding: 140px 0;
}

.icon-box {
  font-size: 40px;
}

.course-card:hover {
  transform: translateY(-8px);
  transition: .3s;
}

.testimonial {
  background: #f8f9fa;
}

.cta {
  background: #0d6efd;
  color: white;
  padding: 70px 0;
}

footer {
  background: #212529;
  color: white;
  padding: 25px;
}