header {
  background-color: #3f72af;
  text-align: center;
  padding: 1em;
}

header h1 {
  color: #fffffe;
  font-size: 2em;
}

nav {
  background-color: #3f72af;
  padding: 1em;
  text-align: center;
}

nav ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

nav ul li {
  display: inline-block;
  margin-right: 1em;
}

nav ul li a {
  color: #fffffe;
  text-decoration: none;
}

nav ul li a:hover {
  text-decoration: underline;
}

.picture-container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 3em;
}

.picture {
  width: 300px;
  height: auto;
  border: solid 1px #094067;
  margin-right: 1em;
  box-shadow: 2px 2px 10px #ccc;
}

p {
  font-size: 16px;
  color: #000000;
  margin: 0;
}

.flex-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.picture-item {
  flex: 1 1 300px;
  margin: 10px;
  text-align: center;
}

.picture {
  max-width: 100%;
}