:root {
    --bg-color: #fdfdfc;
    --text-color: #2b2b2b;
    --heading-color: #111111;
    --accent-color: #e63946;
    --muted-color: #6c757d;
    --card-bg: #ffffff;
    --border-color: #eaeaea;
    --quote-bg: #f4f4f4;
    --primary-color: #e63946;
    --link-color: #2980b9;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Georgia", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.8;
    font-size: 19px;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 20px;
    padding-left: 220px;
}

.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 180px;
    height: 100vh;
    padding: 30px 15px;
    background: var(--bg-color);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    box-sizing: border-box;
}

.sidebar h4 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--muted-color);
    margin-bottom: 15px;
    margin-top: 0;
}

.sidebar-nav {
    list-style: none;
    padding: 0;
    margin: 0;
    flex: 1;
}

.sidebar-nav li {
    margin-bottom: 12px;
}

.sidebar-nav a {
    font-size: 0.85rem;
    color: var(--text-color);
    text-decoration: none;
    display: block;
    padding: 6px 10px;
    border-radius: 6px;
    transition: background 0.2s, color 0.2s;
    line-height: 1.3;
}

.sidebar-nav a:hover {
    background: var(--border-color);
    color: var(--heading-color);
}

.sidebar-nav a.active {
    background: var(--heading-color);
    color: white;
    font-weight: bold;
}

.sidebar-footer {
    position: fixed;
    bottom: 30px;
    left: 0;
    width: 150px;
    padding: 0 15px;
}

@media (max-width: 900px) {
    .container {
        padding-left: 20px;
    }
    .sidebar {
        display: none;
    }
}

header {
    margin-bottom: 60px;
    text-align: center;
}

h1 {
    font-size: 3rem;
    line-height: 1.1;
    color: var(--heading-color);
    margin-bottom: 20px;
    font-weight: 800;
    letter-spacing: -0.03em;
}

.lead {
    font-size: 1.3rem;
    color: var(--muted-color);
    font-weight: 400;
    line-height: 1.6;
}

h2 {
    font-size: 2.2rem;
    color: var(--heading-color);
    margin-top: 60px;
    margin-bottom: 25px;
    font-weight: 700;
    border-bottom: 2px solid var(--heading-color);
    padding-bottom: 10px;
}

h3 {
    font-size: 1.5rem;
    color: var(--heading-color);
    margin-top: 40px;
    margin-bottom: 15px;
}

p {
    margin-bottom: 25px;
}

.book-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0;
    margin: 40px 0;
    box-shadow: 0 4px 20px rgba(0,0,0,0.03);
    display: flex;
    overflow: hidden;
}

.book-cover {
    width: 140px;
    flex-shrink: 0;
    background-color: #f5f5f5;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 20px 10px;
}

.book-cover img {
    width: 100%;
    height: auto;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.book-content {
    padding: 25px 30px;
    flex: 1;
}

.book-year {
    display: inline-block;
    background-color: var(--heading-color);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
    margin-bottom: 15px;
}

.book-title {
    font-size: 1.6rem;
    font-weight: 700;
    margin-top: 0;
    margin-bottom: 15px;
    color: var(--heading-color);
}

@media (max-width: 600px) {
    .book-card {
        flex-direction: column;
    }
    .book-cover {
        width: 100%;
        padding: 20px;
    }
    .book-cover img {
        max-width: 120px;
        margin: 0 auto;
        display: block;
    }
    .book-content {
        padding: 20px;
    }
}

.book-flaw {
    background-color: #fff0f0;
    border-left: 4px solid var(--accent-color);
    padding: 15px;
    margin-top: 20px;
    font-size: 0.95rem;
}

blockquote {
    margin: 50px 0;
    padding: 30px 40px;
    background-color: var(--quote-bg);
    border-left: 4px solid var(--heading-color);
    font-size: 1.3rem;
    font-style: italic;
    color: var(--heading-color);
    border-radius: 0 8px 8px 0;
}

.historical-context {
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    padding: 25px;
    border-radius: 8px;
    margin: 40px 0;
    font-size: 0.95rem;
}

.historical-context h4 {
    margin-top: 0;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
    color: var(--muted-color);
}

ul {
    margin-bottom: 25px;
    padding-left: 20px;
}

li {
    margin-bottom: 12px;
}

strong {
    color: var(--heading-color);
}

hr {
    border: 0;
    height: 1px;
    background: var(--border-color);
    margin: 60px 0;
}

footer {
    margin-top: 80px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    font-size: 0.95rem;
    color: var(--muted-color);
    text-align: center;
}

@media (max-width: 600px) {
    h1 { font-size: 2.2rem; }
    h2 { font-size: 1.8rem; }
    .container { padding: 30px 15px; }
    .book-card { padding: 20px; }
    blockquote { padding: 20px; font-size: 1.1rem; }
}

.subtitle {
    font-size: 1.3rem;
    color: var(--muted-color);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 40px;
}

.meta {
    color: #95a5a6;
    font-size: 0.9em;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    margin-bottom: 40px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    margin: 50px 0;
    border-radius: 12px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.photo-caption {
    font-size: 0.9em;
    color: #7f8c8d;
    text-align: center;
    margin-top: -30px;
    margin-bottom: 40px;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

.infobox {
    background-color: #f4f6f7;
    padding: 30px;
    border-radius: 8px;
    margin: 40px 0;
    border-left: 4px solid #3498db;
}

.infobox h4 {
    margin-top: 0;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    color: var(--text-color);
}

.highlight {
    background-color: #fff3cd;
    padding: 2px 5px;
}

a.content-link {
    color: var(--link-color);
    text-decoration: none;
    border-bottom: 1px dotted var(--link-color);
    transition: all 0.2s;
    font-weight: bold;
}

a.content-link:hover {
    color: var(--primary-color);
    border-bottom: 1px solid var(--primary-color);
}

.centered-image {
    text-align: center;
    margin: 20px 0;
}

.centered-image img {
    max-width: 100%;
    height: auto;
}

.centered-image .caption {
    font-size: 0.85rem;
    color: #888;
    margin-top: 10px;
}

@media (max-width: 600px) {
    .infobox, .historical-context { padding: 15px; }
}

.infobox, .historical-context { overflow-wrap: break-word; }

.dual-photo {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 20px 0 40px 0;
}

.dual-photo img {
    max-width: 400px;
    border: 2px solid #888;
    border-radius: 8px;
}

.sidebar-footer a {
    color: gray;
    text-decoration: none;
    font-size: 14px;
}