body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f9fafc;
    color: #333;
}
header {
    background-color: #44a76f;
    color: white;
    padding: 1rem 0;
    text-align: center;
}
nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
nav ul li {
    display: inline-block;
    margin: 0 15px;
}
nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: bold;
}
nav ul li a:hover {
    text-decoration: underline;
}
main {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1rem;
}
footer {
    background-color: #222;
    color: white;
    text-align: center;
    padding: 1rem 0;
}
h1, h2, h3 {
    color: #2d6a4f;
}
ul {
    padding-left: 1.5rem;
}
.notice {
    background-color: #fff3cd;
    border: 1px solid #ffeeba;
    padding: 1rem;
    margin-top: 2rem;
    font-style: italic;
}
.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 50%;
}