body {
    font-family: system-ui, sans-serif;
    line-height: 1.6;
    max-width: 800px;
    margin: 40px auto;
    padding: 0 20px;
    color: #333;
}
a { color: #007bff; }
header { border-bottom: 1px solid #eee; margin-bottom: 20px; }