body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: white;
    padding: 20px;
    text-align: center;
}

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

nav ul li {
    display: inline;
    margin: 0 15px;
}

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

section {
    padding: 20px;
    margin: 20px;
    background: white;
    border-radius: 5px;
}

footer {
    text-align: center;
    padding: 10px;
    background-color: #333;
    color: white;
}
.modal {
    position: fixed;
    z-index: 1;
    left: 0; top: 0;
    width: 100%; height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.4);
}
.modal-content {
    background-color: #fff;
    margin: 10% auto;
    padding: 20px;
    border-radius: 8px;
    width: 80%;
    max-width: 400px;
    position: relative;
}
.close {
    color: #aaa;
    position: absolute;
    top: 10px; right: 20px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}
.close:hover { color: #000; }