:root {
    --bg: #fafaf7;
    --text: #2c2c2c;
    --text-light: #5a5a5a;
    --accent: #8b4513;
    --accent-light: #a0522d;
    --link: #4a6fa5;
    --link-hover: #2c4a7c;
    --border: #ddd;
    --sidebar-bg: #f0efe8;
    --sidebar-width: 280px;
    --tooltip-bg: #333;
    --tooltip-text: #f5f5f0;
    --code-bg: #f5f2eb;
    --highlight: #fff3cd;
    --max-content: 750px;
    --font-serif: 'Georgia', 'Times New Roman', 'Palatino Linotype', serif;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

html { font-size: 17px; scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: var(--font-serif);
    color: var(--text);
    background: var(--bg);
    line-height: 1.75;
}

/* ----- Sidebar ----- */
.sidebar {
    position: fixed;
    top: 0; left: 0;
    width: var(--sidebar-width);
    height: 100vh;
    overflow-y: auto;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    padding: 2rem 1.25rem;
    font-family: var(--font-sans);
    font-size: 0.82rem;
    z-index: 100;
    transition: transform 0.3s ease;
}

.sidebar-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 0.25rem;
    line-height: 1.3;
}
.sidebar-subtitle {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-style: italic;
}

.sidebar nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
.sidebar nav li { margin-bottom: 0.15rem; }
.sidebar nav a {
    display: block;
    padding: 0.3rem 0.5rem;
    color: var(--text);
    text-decoration: none;
    border-radius: 4px;
    transition: background 0.15s;
}
.sidebar nav a:hover,
.sidebar nav a.active {
    background: rgba(139, 69, 19, 0.1);
    color: var(--accent);
}

.sidebar nav .section-links {
    padding-left: 1rem;
    margin-top: 0.1rem;
}
.sidebar nav .section-links a {
    font-size: 0.78rem;
    color: var(--text-light);
    padding: 0.15rem 0.5rem;
}

.sidebar nav .nav-divider {
    height: 1px;
    background: var(--border);
    margin: 0.75rem 0;
}

/* ----- Mobile menu toggle ----- */
.menu-toggle {
    display: none;
    position: fixed;
    top: 1rem; left: 1rem;
    z-index: 200;
    background: var(--sidebar-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.5rem 0.75rem;
    font-size: 1.2rem;
    cursor: pointer;
    font-family: var(--font-sans);
}

/* ----- Main content ----- */
.content {
    margin-left: var(--sidebar-width);
    padding: 3rem 2.5rem 5rem;
    max-width: calc(var(--max-content) + 5rem);
}

/* ----- Typography ----- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-sans);
    color: var(--accent);
    margin-top: 2.5rem;
    margin-bottom: 0.75rem;
    line-height: 1.3;
}
h1 { font-size: 2rem; margin-top: 0; border-bottom: 2px solid var(--accent); padding-bottom: 0.5rem; }
h2 { font-size: 1.45rem; }
h3 { font-size: 1.15rem; }

p { margin: 0 0 1.2rem; }

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hover); text-decoration: underline; }

strong { font-weight: 700; }
em { font-style: italic; }

hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2rem 0;
}

/* ----- Lists ----- */
ul, ol { padding-left: 1.5rem; margin: 0 0 1.2rem; }
li { margin-bottom: 0.4rem; }

/* ----- Tables ----- */
.table-wrapper { overflow-x: auto; margin: 1.5rem 0; }
table {
    border-collapse: collapse;
    width: 100%;
    font-size: 0.92rem;
    font-family: var(--font-sans);
}
th, td {
    padding: 0.5rem 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}
th { background: var(--sidebar-bg); font-weight: 600; }

/* ----- Glossary tooltips ----- */
.glossary-term {
    border-bottom: 1px dotted var(--accent-light);
    cursor: help;
    position: relative;
}
.glossary-term:hover::after,
.glossary-term:focus::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 8px);
    left: 0;
    background: var(--tooltip-bg);
    color: var(--tooltip-text);
    padding: 0.6rem 0.9rem;
    border-radius: 6px;
    font-size: 0.82rem;
    font-family: var(--font-sans);
    line-height: 1.5;
    max-width: min(420px, calc(100vw - var(--sidebar-width) - 4rem));
    min-width: 200px;
    width: max-content;
    z-index: 150;
    box-shadow: 0 4px 16px rgba(0,0,0,0.25);
    pointer-events: none;
    white-space: normal;
}
.glossary-term:hover::before,
.glossary-term:focus::before {
    content: '';
    position: absolute;
    bottom: calc(100% + 2px);
    left: 1rem;
    border: 6px solid transparent;
    border-top-color: var(--tooltip-bg);
    z-index: 150;
    pointer-events: none;
}
@media (max-width: 900px) {
    .glossary-term:hover::after,
    .glossary-term:focus::after {
        max-width: calc(100vw - 3rem);
        left: 0;
        right: auto;
    }
}

/* ----- Citations ----- */
.citation a {
    font-family: var(--font-sans);
    font-size: 0.7rem;
    color: var(--link);
    text-decoration: none;
    padding: 0 0.1rem;
}
.citation a:hover { text-decoration: underline; }
.citation-missing a { color: #c44; }

/* ----- Chapter links ----- */
.chapter-link {
    color: var(--accent-light);
    font-weight: 600;
}

/* ----- Glossary page ----- */
.glossary-entry {
    margin-bottom: 1rem;
    padding-left: 0.5rem;
}
.glossary-entry .term {
    font-weight: 700;
    font-family: var(--font-sans);
    color: var(--accent);
}
.glossary-entry .definition {
    margin-left: 0.25rem;
}

/* ----- Bibliography page ----- */
.bib-entry {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
    text-indent: -1.5rem;
    font-size: 0.92rem;
}
.bib-entry .ref-id {
    font-family: var(--font-sans);
    font-weight: 600;
    color: var(--accent);
}

/* ----- Page navigation (prev/next) ----- */
.page-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    font-family: var(--font-sans);
    font-size: 0.9rem;
}
.page-nav a {
    color: var(--accent);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    transition: background 0.15s;
}
.page-nav a:hover { background: var(--sidebar-bg); }

/* ----- Responsive ----- */
@media (max-width: 900px) {
    .sidebar { transform: translateX(-100%); }
    .sidebar.open { transform: translateX(0); }
    .menu-toggle { display: block; }
    .content { margin-left: 0; padding: 4rem 1.5rem 3rem; }
}
@media (max-width: 600px) {
    html { font-size: 15px; }
    .content { padding: 4rem 1rem 2rem; }
}