body {
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: #f0f2f5;
    color: #333;
}
.container {
    width: 90%;
    max-width: 960px;
    margin: 20px auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
header.main-header {
    background-color: #2c3e50;
    color: #fff;
    padding: 1em 0;
    text-align: center;
}
header.main-header h1 { margin: 0; font-size: 2.2em; }
header.main-header h1 a { color: #fff; text-decoration: none; }
nav.main-nav ul { list-style: none; padding: 0; text-align: center; background-color: #34495e; margin:0; }
nav.main-nav ul li { display: inline; }
nav.main-nav ul li a { text-decoration: none; color: #ecf0f1; padding: 12px 18px; display: inline-block; }
nav.main-nav ul li a:hover { background-color: #46627f; }
footer.main-footer { text-align: center; padding: 15px; margin-top: 25px; background-color: #2c3e50; color: #bdc3c7; font-size: 0.9em; }
main h2 { color: #34495e; }
code { background-color: #eee; padding: 2px 4px; border-radius: 3px; font-family: monospace;}