/* Ray Tracing series: docs shell with the same light/dark reader themes. */
html.booklet {
    --book-paper: #fbfaf6;
    --book-surface: #ffffff;
    --book-ink: #17202b;
    --book-muted: #647080;
    --book-rule: #dfe3e8;
    --book-soft: #f1f3f5;
    --book-accent: #b5522e;
    --book-accent-soft: #f7e9df;
    --book-code: #f4f1ea;
    --book-nav-bg: rgba(251, 250, 246, 0.96);
    --book-side-bg: rgba(251, 250, 246, 0.98);
    --book-shadow: rgba(23, 32, 43, 0.12);
    --book-scrim: rgba(23, 32, 43, 0.42);
    background: var(--book-paper);
}

html.booklet.reader-dark,
html.booklet.reader.reader-dark {
    --book-paper: #0e1116;
    --book-surface: #161b22;
    --book-ink: #ede7d8;
    --book-muted: #8b95a8;
    --book-rule: #2a3140;
    --book-soft: #1a2029;
    --book-accent: #e08a62;
    --book-accent-soft: #2a1c16;
    --book-code: #0a0d11;
    --book-nav-bg: rgba(14, 17, 22, 0.96);
    --book-side-bg: rgba(14, 17, 22, 0.98);
    --book-shadow: rgba(0, 0, 0, 0.35);
    --book-scrim: rgba(0, 0, 0, 0.55);
}

@media (prefers-color-scheme: dark) {
    html.booklet.reader:not(.reader-light) {
        --book-paper: #0e1116;
        --book-surface: #161b22;
        --book-ink: #ede7d8;
        --book-muted: #8b95a8;
        --book-rule: #2a3140;
        --book-soft: #1a2029;
        --book-accent: #e08a62;
        --book-accent-soft: #2a1c16;
        --book-code: #0a0d11;
        --book-nav-bg: rgba(14, 17, 22, 0.96);
        --book-side-bg: rgba(14, 17, 22, 0.98);
        --book-shadow: rgba(0, 0, 0, 0.35);
        --book-scrim: rgba(0, 0, 0, 0.55);
    }
}

html.booklet body,
html.booklet.reader body {
    min-width: 0;
    background: var(--book-paper) !important;
    color: var(--book-ink) !important;
    font-family: 'Satoshi', system-ui, -apple-system, 'Segoe UI', sans-serif !important;
    font-size: 16px;
    line-height: 1.65;
    text-shadow: none !important;
}

html.booklet #reader-bg { display: none !important; }
html.booklet body > .navbar { position: fixed; z-index: 1040; }
html.booklet .navbar .navbar-inner {
    min-height: 48px;
    background: var(--book-nav-bg) !important;
    border: 0;
    border-bottom: 1px solid var(--book-rule);
    box-shadow: none !important;
    filter: none;
}
html.booklet .navbar .container {
    width: auto;
    max-width: none;
    min-height: 48px;
    padding: 0 24px;
    box-sizing: border-box;
}
html.booklet .navbar .nav-collapse,
html.booklet .navbar .nav,
html.booklet .navbar .nav > li {
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
}
html.booklet .navbar .brand,
html.booklet .navbar .nav > li > a {
    color: var(--book-ink) !important;
    background: transparent !important;
    font-family: 'Satoshi', system-ui, sans-serif !important;
    text-shadow: none !important;
}
html.booklet .navbar .brand {
    font-size: 16px;
    font-weight: 780;
    line-height: 48px;
    height: 48px;
    padding: 0;
    margin: 0;
    display: inline-flex;
    align-items: center;
}
html.booklet .navbar .nav > li > a {
    color: var(--book-muted) !important;
    font-size: 14px;
    font-weight: 600;
    line-height: 20px;
    height: 48px;
    padding-top: 0 !important;
    padding-bottom: 0 !important;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
html.booklet .navbar .nav > li > a:hover,
html.booklet .navbar .nav > li.open > a { color: var(--book-accent) !important; }

/* Bootstrap caret uses margin-top + vertical-align:top; that drops under flex centering. */
html.booklet .navbar .caret,
html.booklet.reader .navbar .caret {
    display: inline-block !important;
    width: auto !important;
    height: auto !important;
    margin: 0 !important;
    border: 0 !important;
    vertical-align: middle !important;
    line-height: 1 !important;
    position: static !important;
    top: auto !important;
    float: none !important;
}
html.booklet .navbar .caret:before,
html.booklet.reader .navbar .caret:before {
    content: "▾" !important;
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    line-height: 1;
    color: var(--book-muted);
}
html.booklet .navbar .nav > li.open > a .caret:before,
html.booklet .navbar .nav > li > a:hover .caret:before {
    color: var(--book-accent);
}

/* Match the main blog bar: title and links share one vertical center line. */
@media (min-width: 980px) {
    html.booklet .navbar .navbar-inner > .container {
        display: flex;
        align-items: center;
        min-height: 48px;
    }
    html.booklet .navbar .brand {
        float: none;
        margin-left: 0;
        margin-right: 12px;
    }
    html.booklet .navbar .nav-collapse {
        flex: 1;
        height: auto;
        overflow: visible;
    }
    html.booklet .navbar .nav {
        float: none;
        display: flex;
        align-items: center;
        margin: 0;
        height: 48px;
    }
    html.booklet .navbar .nav > li {
        float: none;
        display: flex;
        align-items: center;
        height: 48px;
    }
}

html.booklet .dropdown-menu {
    background: var(--book-surface) !important;
    border: 1px solid var(--book-rule) !important;
    border-radius: 10px;
    box-shadow: 0 16px 40px var(--book-shadow) !important;
}
html.booklet .dropdown-menu > li > a {
    color: var(--book-ink) !important;
    font-family: 'Satoshi', system-ui, sans-serif !important;
}
html.booklet .dropdown-menu > li > a:hover { background: var(--book-soft) !important; }

html.booklet #content.booklet-container,
html.booklet.reader #content.booklet-container {
    width: auto !important;
    max-width: none !important;
    margin: 0 !important;
    padding: 48px 0 0 !important;
    position: relative;
    z-index: 1;
}
html.booklet footer.container { display: none; }

.booklet-shell {
    display: grid;
    grid-template-columns: 250px minmax(0, 1fr);
    min-height: calc(100vh - 48px);
}
.booklet-sidebar {
    position: sticky;
    top: 48px;
    height: calc(100vh - 48px);
    box-sizing: border-box;
    overflow-y: auto;
    border-right: 1px solid var(--book-rule);
    background: var(--book-side-bg);
    padding: 28px 16px 36px;
}
.booklet-series-link {
    display: block;
    margin: 0 8px 18px;
    color: var(--book-ink) !important;
    font-size: 15px;
    font-weight: 750;
    text-decoration: none !important;
}
.booklet-series-link:hover { color: var(--book-accent) !important; }

.booklet-index ol { list-style: none; margin: 0; padding: 0; }
.booklet-index li { list-style: none; margin: 2px 0; }
.booklet-index li:before { content: none !important; }
.booklet-index a {
    display: grid;
    grid-template-columns: 22px minmax(0, 1fr);
    align-items: start;
    gap: 8px;
    padding: 8px 9px;
    border-radius: 10px;
    color: var(--book-muted) !important;
    text-decoration: none !important;
}
.booklet-index a span {
    color: inherit !important;
    font-size: 12px;
    font-weight: 700;
    line-height: 1.5;
    font-variant-numeric: tabular-nums;
}
.booklet-index a b {
    color: inherit !important;
    font-size: 13.5px;
    font-weight: 650;
    line-height: 1.35;
}
.booklet-index a:hover { background: var(--book-soft); color: var(--book-ink) !important; }
.booklet-index a.is-active {
    background: var(--book-accent-soft) !important;
    color: var(--book-accent) !important;
}

.booklet-content {
    min-width: 0;
    padding: 40px 48px 80px;
}
.booklet-article {
    max-width: 42rem;
    margin: 0 auto;
}
.booklet-article > header { margin-bottom: 1.4rem; }

/* Beat reader heading rules that otherwise paint light ink on light paper. */
html.booklet .booklet-article h1,
html.booklet.reader .booklet-article h1,
html.booklet .booklet-prose h2,
html.booklet.reader .booklet-prose h2,
html.booklet .booklet-prose h3,
html.booklet.reader .booklet-prose h3,
html.booklet .booklet-prose h4,
html.booklet.reader .booklet-prose h4 {
    color: var(--book-ink) !important;
    text-shadow: none !important;
}

.booklet-article h1 {
    margin: 0;
    font-family: Georgia, 'Times New Roman', serif !important;
    font-size: clamp(2rem, 4vw, 2.55rem);
    font-weight: 700;
    line-height: 1.12;
    letter-spacing: -0.02em;
}

.booklet-prose > *:first-child { margin-top: 0; }
.booklet-prose h2 {
    margin: 2rem 0 0.7rem;
    font-size: 1.35rem;
    font-weight: 750;
    line-height: 1.25;
}
.booklet-prose h3 {
    margin: 1.5rem 0 0.55rem;
    font-size: 1.08rem;
    font-weight: 750;
}
html.booklet .booklet-prose p,
html.booklet .booklet-prose li,
html.booklet .booklet-prose td,
html.booklet .booklet-prose th,
html.booklet.reader .booklet-prose p,
html.booklet.reader .booklet-prose li {
    color: var(--book-ink) !important;
    font-size: 1.02rem;
    line-height: 1.72;
    text-shadow: none !important;
}
.booklet-prose p { margin: 0 0 1rem; }
html.booklet .booklet-prose ul,
html.booklet.reader .booklet-prose ul {
    list-style: disc outside !important;
    margin: 0 0 1.15rem;
    padding-left: 1.5rem;
}
html.booklet .booklet-prose ol,
html.booklet.reader .booklet-prose ol {
    list-style: decimal outside !important;
    margin: 0 0 1.15rem;
    padding-left: 1.5rem;
}
html.booklet .booklet-prose li,
html.booklet.reader .booklet-prose li {
    display: list-item !important;
    list-style: inherit !important;
    margin: 0.35rem 0;
    padding-left: 0.2rem;
    text-indent: 0;
}
html.booklet .booklet-prose li::marker,
html.booklet.reader .booklet-prose li::marker {
    color: var(--book-muted);
}
html.booklet .booklet-prose li:before,
html.booklet.reader .booklet-prose li:before {
    content: none !important;
}
html.booklet .booklet-prose li > ul,
html.booklet .booklet-prose li > ol {
    margin: 0.35rem 0 0.2rem;
}
html.booklet .booklet-prose a,
html.booklet.reader .booklet-prose a { color: var(--book-accent) !important; }
.booklet-prose code {
    padding: 0.08em 0.28em;
    border-radius: 5px;
    background: var(--book-soft);
    color: var(--book-ink) !important;
    font-family: Consolas, 'SF Mono', monospace;
    font-size: 0.92em;
}
.booklet-prose pre {
    overflow-x: auto;
    margin: 0 0 1.2rem;
    padding: 14px 16px;
    border: 1px solid var(--book-rule);
    border-radius: 12px;
    background: var(--book-code);
}
.booklet-prose pre code {
    padding: 0;
    background: transparent;
    font-size: 0.9rem;
    line-height: 1.55;
}
.booklet-prose img {
    display: block;
    width: 100%;
    height: auto;
    margin: 1.2rem 0 0.35rem;
    border: 1px solid var(--book-rule);
    border-radius: 14px;
    background: var(--book-surface);
}
html.booklet .booklet-prose em,
html.booklet.reader .booklet-prose em {
    display: block;
    margin: 0 0 1.2rem;
    color: var(--book-muted) !important;
    font-size: 0.94rem;
    font-style: italic;
    line-height: 1.45;
}
html.booklet .booklet-prose strong,
html.booklet.reader .booklet-prose strong {
    color: var(--book-ink) !important;
    font-weight: 750;
}

/* KaTeX equations: quiet display math that matches booklet type. */
html.booklet .booklet-prose .katex { font-size: 1.05em; color: var(--book-ink); }
html.booklet .booklet-prose .katex-display {
    margin: 1.1rem 0 1.25rem;
    overflow-x: auto;
    overflow-y: hidden;
    padding: 0.15rem 0;
}
html.booklet .booklet-prose .katex-display > .katex {
    text-align: center;
    white-space: normal;
}
html.booklet.reader-dark .booklet-prose .katex,
html.booklet.reader.reader-dark .booklet-prose .katex { color: var(--book-ink); }
@media (prefers-color-scheme: dark) {
    html.booklet.reader:not(.reader-light) .booklet-prose .katex { color: var(--book-ink); }
}

.booklet-pagination {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 2.4rem;
    padding-top: 1.2rem;
    border-top: 1px solid var(--book-rule);
}
.booklet-pagination a {
    min-width: 0;
    color: var(--book-ink) !important;
    font-size: 0.98rem;
    font-weight: 650;
    line-height: 1.35;
    text-decoration: none !important;
}
.booklet-pagination a[rel="next"] { text-align: right; }
.booklet-pagination a:hover { color: var(--book-accent) !important; }

.booklet-mobile-bar,
.booklet-menu-scrim { display: none; }

html.booklet .booklet-series-link,
html.booklet .booklet-index a,
html.booklet .booklet-pagination a { color: var(--book-ink) !important; }
html.booklet .booklet-index a { color: var(--book-muted) !important; }
html.booklet .booklet-index a.is-active {
    color: var(--book-accent) !important;
    background: var(--book-accent-soft) !important;
}

/* Keep theme controls, hide retro/reader flip and animated bg pause on booklet pages. */
html.booklet #reader-toggle,
html.booklet #reader-bg-pause { display: none !important; }
html.booklet #reader-controls {
    display: flex !important;
    gap: 8px;
}
html.booklet #reader-theme {
    color: var(--book-muted) !important;
    border-color: var(--book-rule) !important;
    background: var(--book-surface) !important;
}
html.booklet #reader-theme:hover { color: var(--book-ink) !important; }

@media (max-width: 979px) {
    html.booklet .navbar .btn-navbar {
        display: grid;
        place-items: center;
        width: 38px;
        height: 32px;
        box-sizing: border-box;
        margin-top: 8px;
        padding: 0;
        border: 1px solid var(--book-rule);
        border-radius: 8px;
        background: var(--book-surface) !important;
        box-shadow: none !important;
        color: var(--book-ink) !important;
        font-size: 0;
    }
    html.booklet .navbar .btn-navbar:before {
        content: "☰" !important;
        color: var(--book-ink);
        font: 700 18px/1 system-ui, sans-serif;
    }
    html.booklet .navbar .btn-navbar:after { content: none !important; }
    html.booklet .navbar .nav-collapse { background: var(--book-paper) !important; }
    html.booklet .navbar .nav > li > a {
        height: auto;
        line-height: 1.4;
        padding: 10px 15px !important;
    }
}

@media (min-width: 768px) and (max-width: 1050px) {
    .booklet-shell { grid-template-columns: 220px minmax(0, 1fr); }
    .booklet-content { padding: 32px 28px 64px; }
}

@media (max-width: 767px) {
    html.booklet #content.booklet-container,
    html.booklet.reader #content.booklet-container { padding-top: 48px !important; }
    .booklet-mobile-bar {
        position: sticky;
        top: 48px;
        z-index: 20;
        display: flex;
        align-items: center;
        gap: 12px;
        padding: 10px 14px;
        border-bottom: 1px solid var(--book-rule);
        background: var(--book-nav-bg);
    }
    #booklet-menu-toggle {
        display: inline-flex;
        align-items: center;
        gap: 8px;
        margin: 0;
        padding: 8px 11px;
        border: 1px solid var(--book-rule);
        border-radius: 999px;
        background: var(--book-surface);
        color: var(--book-ink);
        font: 650 13px/1 'Satoshi', system-ui, sans-serif;
    }
    .booklet-menu-icon {
        display: inline-block;
        width: 15px;
        color: currentColor !important;
        font: 700 16px/1 system-ui, sans-serif !important;
    }
    .booklet-mobile-title {
        min-width: 0;
        overflow: hidden;
        color: var(--book-muted);
        font-size: 12px;
        white-space: nowrap;
        text-overflow: ellipsis;
    }
    .booklet-shell { display: block; min-height: 0; }
    .booklet-sidebar {
        position: fixed;
        z-index: 1035;
        top: 44px;
        left: 0;
        width: min(86vw, 310px);
        height: calc(100vh - 44px);
        padding: 24px 18px 40px;
        border-right: 1px solid var(--book-rule);
        box-shadow: 16px 0 48px var(--book-shadow);
        transform: translateX(-110%);
        transition: transform 0.2s ease;
    }
    .booklet-menu-open .booklet-sidebar { transform: translateX(0); }
    .booklet-menu-scrim {
        position: fixed;
        z-index: 1030;
        inset: 44px 0 0;
        display: block;
        background: var(--book-scrim);
    }
    .booklet-menu-scrim[hidden] { display: none !important; }
    .booklet-content { padding: 22px 18px 56px; }
    .booklet-pagination { grid-template-columns: 1fr; }
    .booklet-pagination a[rel="next"] { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
    .booklet-sidebar { transition: none; }
}