:root {
    --bg-color: #000000;
    --text-color: #e0e0e0;
    --accent-color: #1a1a2e;
    --red-accent: #FF0000;
    --link-color: #ff6b6b;
}
body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
}
header {
    background-color: var(--accent-color);
    padding: 20px;
    text-align: center;
    border-bottom: 2px solid var(--red-accent);
}
header a {
    color: white;
    text-decoration: none;
    font-size: 24px;
    font-weight: bold;
}
nav {
    display: flex;
    flex-wrap: wrap;
    background-color: #111;
    padding: 10px;
    justify-content: center;
    border-bottom: 1px solid #333;
}
nav a {
    color: var(--text-color);
    text-decoration: none;
    margin: 5px 15px;
    min-width: 44px;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
}
nav a:hover {
    color: var(--red-accent);
}
main {
    display: flex;
    flex-direction: column;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}
.sidebar {
    width: 100%;
    border-bottom: 1px solid #333;
    padding-right: 0;
    margin-bottom: 20px;
}
.sidebar ul {
    list-style: none;
    padding: 0;
}
.sidebar li {
    margin-bottom: 10px;
}
.sidebar a {
    color: var(--link-color);
    text-decoration: none;
    display: block;
    min-height: 44px;
    display: flex;
    align-items: center;
}
.content {
    flex: 1;
    padding-left: 0;
}
h1, h2, h3 {
    color: white;
    font-weight: bold;
}
img {
    max-width: 100%;
    height: auto;
    border: 1px solid #333;
    margin: 20px 0;
}
.toc {
    background-color: #111;
    padding: 20px;
    border: 1px solid #333;
    margin-bottom: 20px;
}
.ad-container {
    margin: 20px 0;
    text-align: center;
    background-color: #222;
    padding: 10px;
    border: 1px dashed #555;
}
footer {
    background-color: var(--accent-color);
    padding: 20px;
    text-align: center;
    border-top: 2px solid var(--red-accent);
    margin-top: 40px;
}
footer a {
    color: var(--text-color);
    text-decoration: none;
    margin: 0 10px;
}
.expert-byline {
    font-style: italic;
    color: #aaa;
    margin-bottom: 20px;
}
@media (min-width: 769px) {
    main {
        flex-direction: row;
    }
    .sidebar {
        width: 250px;
        padding-right: 20px;
        border-right: 1px solid #333;
        border-bottom: none;
        margin-bottom: 0;
    }
    .content {
        padding-left: 20px;
    }
}