body {
  font-family: "Microsoft YaHei", sans-serif;
  margin: 0;
  padding: 0;
  background: #f5f5f5;
  color: #333;
}
header {
  background-color: #ff5a00;
  color: white;
  padding: 15px;
  text-align: center;
}
nav a {
  margin: 0 10px;
  color: white;
  text-decoration: none;
}
main {
  padding: 20px;
}
.product-list {
  list-style: none;
  padding-left: 0;
}
.product-list li {
  background: white;
  margin-bottom: 10px;
  padding: 15px;
  border-radius: 5px;
}
.note {
  font-size: 0.9em;
  color: #777;
}
footer {
  text-align: center;
  font-size: 0.8em;
  padding: 10px;
  color: #999;
}