body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0;
    background-color: #f4f6f8;
    color: #333;
}

header {
    background-color: #1e293b;
    color: #fff;
    padding: 30px;
    text-align: center;
}

.container {
    max-width: 900px;
    margin: auto;
    padding: 20px;
}

.intro, .lessons {
    background: #fff;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 5px;
}

h2 {
    color: #1e293b;
}

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

ul li {
    margin-bottom: 10px;
}

ul li a {
    text-decoration: none;
    color: #2563eb;
    font-weight: bold;
}

ul li a:hover {
    text-decoration: underline;
}

code {
    background: #f1f5f9;
    padding: 5px;
    display: block;
    border-left: 4px solid #2563eb;
    margin-top: 10px;
}

footer {
    text-align: center;
    padding: 15px;
    background: #1e293b;
    color: #fff;
}