body {
    font-family: "Segoe UI", Arial, sans-serif;
    background-color: #f9f9fb;
    color: #333;
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

header {
    background: #003366;
    color: white;
    text-align: center;
    padding: 2rem 1rem;
}

header h1 {
    margin-bottom: 0.2rem;
    font-size: 2.2rem;
}

header h2 {
    font-size: 1.6rem;
    margin-top: 0;
}

.author {
    font-style: italic;
    font-size: 1rem;
    color: #ddd;
}

main {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1.5rem;
    background: white;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    border-radius: 10px;
}

h3 {
    color: #003366;
    border-bottom: 2px solid #003366;
    padding-bottom: 0.3rem;
}

.sql-block {
    background: #f4f4f4;
    border-left: 4px solid #003366;
    padding: 1rem;
    margin: 1rem 0;
    overflow-x: auto;
}

pre {
    margin: 0;
    font-family: "Courier New", monospace;
    font-size: 0.9rem;
}

ul {
    list-style: disc;
    margin-left: 2rem;
}

footer {
    background: #003366;
    color: white;
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
    margin-top: 2rem;
}