header {
  text-align: center;
  margin-top: 40px; }

footer div {
  text-align: center;
  margin-top: 70px; }

footer {
  margin-bottom: 80px; }

#usefulness {
  text-align: center;
  margin-left: auto;
  margin-right: auto; }

.useful-image {
  padding: 20px; }

.useful-image img {
  border-radius: 8px;
  box-shadow: 0px 2px 3px rgba(0, 0, 0, 0.2);
  max-width: 300px; }

.promo-video {
  margin-left: auto;
  margin-right: auto;
  width: 260px;
  text-align: center; }

video {
  border-radius: 5px;
  box-shadow: 0px 2px 8px rgba(0, 0, 0, 0.5);
  margin-top: 40px; }

.video {
  border-radius: 5px;
  box-shadow: 0px 2px 8px rgba(0, 0, 0, 0.5);
  margin-top: 40px; }