body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, sans-serif;
    background: #f5f5f5;
    color: #333;
}

.header {
    background: #24292f;
    color: #fff;
    padding: 40px;
    text-align: center;
}

.container {
    max-width: 960px;
    margin: 40px auto;
    padding: 0 20px;
}

.footer {
    text-align: center;
    padding: 20px;
    font-size: 14px;
    color: #777;
}