body {
    display: flex;
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
.sidebar {
    width: 250px;
    height: 100vh;
    background: #f5f5f5;
    padding: 20px;
    overflow-y: auto;
    position: fixed;
}
.content {
    margin-left: 290px;
    padding: 20px;
    max-width: 800px;
}
.nav-list {
    list-style: none;
    padding: 0;
}
.nav-section {
    margin-bottom: 15px;
}
.nav-section-header {
    font-weight: bold;
    cursor: pointer;
    padding: 5px;
    background: #e0e0e0;
    border-radius: 4px;
}
.nav-items {
    list-style: none;
    padding-left: 15px;
    display: none;
}
.nav-items.active {
    display: block;
}
.nav-items a {
    color: #333;
    text-decoration: none;
    display: block;
    padding: 5px;
}
.nav-items a:hover {
    background: #e0e0e0;
    border-radius: 4px;
}
/* Nested list styling */
.content ul,
.content ol {
    padding-left: 2em;
    margin-bottom: 1em;
}
.content li {
    margin-bottom: 0.5em;
}
/* Single-page sections */
.page-section {
    display: none;
}
.page-section.active {
    display: block;
}