body {
  font-family: Arial, sans-serif;
  font-size: 25px;
  background-color: #efefef;
  color: #000;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;     /* stack header/main/footer */
}

header {
  background-image: url("media/background-header1.jpg");
  background-size: cover;
  background-position: center;
  -webkit-text-stroke-width: 1px;
  -webkit-text-stroke-color: rgb(0, 0, 0);
  color: #7cacea;
  padding: 18px 0;
  text-align: center;
  border-bottom: 1px solid #efefef;
}

nav {
  margin-top: 10px;
  padding: 10px 0;
  text-align: center;
  border-bottom: 0px solid #efefef;
}

nav a {
  color: #72afff;
  text-decoration: none;
  font-size: 20px;
  margin: 0 15px;
  font-weight: bold;
}

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

main {
  padding: 20px;
  max-width: 900px;
  margin: 20px auto;
  flex: 1 0 auto;
  background: #f7f7f7;
  border-radius: 6px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}

footer {
  text-align: center;
  background-color: #333;
  color: white;
  padding: 15px 0;
  border-top: 1px solid #222;
  width: 100%;
}