* {
  margin: 0px;
  padding: 0px;
}

body {
  width: 960px;
  min-height: 640px;
  display: flex;
  flex-direction: column;
  margin: 0 auto;
  font-family: 'Times New Roman';
  background-image: url("../img/background_nhi.jpg");
  background-repeat: no-repeat;
  background-size: auto;
  background-position: center;
}

header {
  color: #222222;
  background-color: #FFE300;
  margin-bottom: 20px;
}

header h1 {
  text-align: center;
  font-size: 56px;
  padding: 0px 0px 5px 15px;
}

main {
  flex: 1;
}

footer {
  margin-bottom: 10px;
  font-size: 10px;
  margin-left: 30px;
  color: white;
}