/* Chatty docs theme (AGE-255).
 *
 * Layered over mdBook 0.5's stock stylesheets. Two themes are exposed in the
 * header toggle: `light` and `ayu` (labelled "Dark"). Everything below is
 * expressed through the same custom properties mdBook's own CSS reads, plus a
 * handful of Chatty tokens, so the stock chrome (sidebar, search, menu bar)
 * picks the palette up without further overrides.
 */

:root {
    --sidebar-target-width: 272px;
    --page-padding: 24px;
    --content-max-width: 760px;
    --menu-bar-height: 56px;
    --mono-font: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    --code-font-size: 0.875em;

    --chatty-accent: #5357d2;
    --chatty-accent-soft: #e9eafb;
    --chatty-muted: #5b6472;
    --chatty-rule: #d8dce4;
    --chatty-surface: #ffffff;
    --chatty-code-bg: #eef0f5;
    --chatty-shadow: 0 1px 2px rgba(22, 26, 34, 0.06), 0 8px 24px rgba(22, 26, 34, 0.08);
    --chatty-note: #2f6fdb;
    --chatty-tip: #1f7a3a;
    --chatty-warning: #9a6108;
    --chatty-caution: #b3400f;
}

/* ---- Palettes ---------------------------------------------------------- */

.light, html:not(.js) {
    --bg: #f7f8fa;
    --fg: #161a22;

    --sidebar-bg: #f7f8fa;
    --sidebar-fg: #3d4553;
    --sidebar-non-existant: #a0a7b4;
    --sidebar-active: var(--chatty-accent);
    --sidebar-spacer: var(--chatty-rule);

    --scrollbar: #b8bec9;

    --icons: #6b7382;
    --icons-hover: #161a22;

    --links: #4548c4;

    --inline-code-color: #2f3340;

    --theme-popup-bg: #ffffff;
    --theme-popup-border: var(--chatty-rule);
    --theme-hover: #eef0f5;

    --quote-bg: #ffffff;
    --quote-border: var(--chatty-rule);

    --table-border-color: var(--chatty-rule);
    --table-header-bg: #f1f2f6;
    --table-alternate-bg: #fafbfc;

    --searchbar-border-color: var(--chatty-rule);
    --searchbar-bg: #ffffff;
    --searchbar-fg: #161a22;
    --searchbar-shadow-color: rgba(83, 87, 210, 0.25);
    --searchresults-header-fg: var(--chatty-muted);
    --searchresults-border-color: var(--chatty-rule);
    --searchresults-li-bg: #ffffff;
    --search-mark-bg: #dcdefa;

    --color-scheme: light;
    --copy-button-filter: invert(45%);
    --copy-button-filter-hover: invert(30%) sepia(60%) saturate(2000%) hue-rotate(220deg);
    --footnote-highlight: var(--chatty-accent-soft);
    --overlay-bg: rgba(22, 26, 34, 0.35);

    --blockquote-note-color: var(--chatty-note);
    --blockquote-tip-color: var(--chatty-tip);
    --blockquote-important-color: var(--chatty-accent);
    --blockquote-warning-color: var(--chatty-warning);
    --blockquote-caution-color: var(--chatty-caution);
    --sidebar-header-border-color: var(--chatty-accent);
}

.ayu, .coal, .navy {
    --chatty-accent: #8f92f2;
    --chatty-accent-soft: #262a4d;
    --chatty-muted: #9aa3b2;
    --chatty-rule: #2a3040;
    --chatty-surface: #1a1e26;
    --chatty-code-bg: #20242e;
    --chatty-shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.35);
    --chatty-note: #7fb0ff;
    --chatty-tip: #7dd39a;
    --chatty-warning: #e6bb62;
    --chatty-caution: #f0a27c;

    --bg: #12151b;
    --fg: #e6e9ef;

    --sidebar-bg: #12151b;
    --sidebar-fg: #b6bdc9;
    --sidebar-non-existant: #5c6473;
    --sidebar-active: var(--chatty-accent);
    --sidebar-spacer: var(--chatty-rule);

    --scrollbar: #3a4152;

    --icons: #8c94a3;
    --icons-hover: #e6e9ef;

    --links: #9b9ef5;

    --inline-code-color: #dfe3ea;

    --theme-popup-bg: #1a1e26;
    --theme-popup-border: var(--chatty-rule);
    --theme-hover: #242935;

    --quote-bg: #1a1e26;
    --quote-border: var(--chatty-rule);

    --table-border-color: var(--chatty-rule);
    --table-header-bg: #1e2330;
    --table-alternate-bg: #171b22;

    --searchbar-border-color: var(--chatty-rule);
    --searchbar-bg: #1a1e26;
    --searchbar-fg: #e6e9ef;
    --searchbar-shadow-color: rgba(143, 146, 242, 0.3);
    --searchresults-header-fg: var(--chatty-muted);
    --searchresults-border-color: var(--chatty-rule);
    --searchresults-li-bg: #1a1e26;
    --search-mark-bg: #3b3f7a;

    --color-scheme: dark;
    --copy-button-filter: invert(60%);
    --copy-button-filter-hover: invert(80%);
    --footnote-highlight: var(--chatty-accent-soft);
    --overlay-bg: rgba(0, 0, 0, 0.5);

    --blockquote-note-color: var(--chatty-note);
    --blockquote-tip-color: var(--chatty-tip);
    --blockquote-important-color: var(--chatty-accent);
    --blockquote-warning-color: var(--chatty-warning);
    --blockquote-caution-color: var(--chatty-caution);
    --sidebar-header-border-color: var(--chatty-accent);
}

/* ---- Base type --------------------------------------------------------- */

html {
    font-family: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    line-height: 1.65;
}

.content main {
    max-width: var(--content-max-width);
}

.content h1,
.content h2,
.content h3,
.content h4 {
    font-weight: 600;
    letter-spacing: -0.015em;
    line-height: 1.2;
    text-wrap: balance;
}

.content h1 { font-size: 2.1rem; margin-top: 0.5em; }
.content h2 { font-size: 1.5rem; margin-top: 2.2em; padding-bottom: 0.3em; border-bottom: 1px solid var(--chatty-rule); }
.content h3 { font-size: 1.15rem; margin-top: 1.8em; }
.content h4 { font-size: 1rem; margin-top: 1.5em; }

.content p,
.content ul,
.content ol {
    margin-bottom: 1em;
}

/* The one-line "When to read this" dek every page opens with. */
.content h1 + p > strong:first-child {
    color: var(--chatty-muted);
    font-weight: 500;
}

.content a {
    color: var(--links);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.12s ease;
}

.content a:hover {
    border-bottom-color: currentColor;
    text-decoration: none;
}

/* Inline code */
:not(pre) > code {
    background: var(--chatty-code-bg);
    color: var(--inline-code-color);
    border-radius: 4px;
    padding: 0.1em 0.35em;
    font-size: 0.88em;
}

/* Code blocks */
pre {
    border: 1px solid var(--chatty-rule);
    border-radius: 8px;
}

pre > .buttons {
    opacity: 0;
    transition: opacity 0.12s ease;
}

pre:hover > .buttons,
pre:focus-within > .buttons {
    opacity: 1;
}

/* ---- Tables ------------------------------------------------------------ */

.content table {
    display: table;
    width: 100%;
    margin: 1.25rem 0 1.5rem;
    font-size: 0.9rem;
    border: 1px solid var(--chatty-rule);
    border-radius: 8px;
    border-spacing: 0;
    overflow: hidden;
}

.content table thead th {
    text-align: left;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--chatty-muted);
    background: var(--table-header-bg);
    padding: 0.6rem 0.75rem;
    border: 0;
    border-bottom: 1px solid var(--chatty-rule);
}

.content table td {
    padding: 0.55rem 0.75rem;
    border: 0;
    border-bottom: 1px solid var(--chatty-rule);
    vertical-align: top;
}

.content table tbody tr:last-child td {
    border-bottom: 0;
}

.content table tbody tr:nth-child(2n) {
    background: var(--table-alternate-bg);
}

/* Wide tables scroll inside their own box, never the page. */
.content .table-wrapper {
    overflow-x: auto;
}

/* ---- Images and figures ----------------------------------------------- */

.content img {
    max-width: 100%;
    height: auto;
    border: 1px solid var(--chatty-rule);
    border-radius: 8px;
    box-shadow: var(--chatty-shadow);
    margin: 0.5rem 0 1.25rem;
}

/* Inline icons or badges should not get the frame. */
.content img[width][height],
.content h1 img,
.content a > img {
    border: 0;
    box-shadow: none;
    margin: 0;
}

/* ---- Callouts ---------------------------------------------------------- */
/* mdBook 0.5 renders `> [!NOTE]` blockquotes as
 * blockquote.blockquote-tag.blockquote-tag-<kind> with a .blockquote-tag-title;
 * plain blockquotes are quotations and stay quiet. */

blockquote {
    margin: 1.25rem 0;
    padding: 0.75rem 1rem;
    background: var(--quote-bg);
    border: 1px solid var(--quote-border);
    border-left: 3px solid var(--chatty-muted);
    border-radius: 6px;
    color: var(--fg);
}

blockquote p:last-child {
    margin-bottom: 0;
}

blockquote.blockquote-tag { border-left-width: 3px; }
blockquote.blockquote-tag-note { border-left-color: var(--blockquote-note-color); }
blockquote.blockquote-tag-tip { border-left-color: var(--blockquote-tip-color); }
blockquote.blockquote-tag-important { border-left-color: var(--blockquote-important-color); }
blockquote.blockquote-tag-warning { border-left-color: var(--blockquote-warning-color); }
blockquote.blockquote-tag-caution { border-left-color: var(--blockquote-caution-color); }

blockquote.blockquote-tag .blockquote-tag-title {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 0.35rem;
}
blockquote.blockquote-tag .blockquote-tag-title svg { fill: currentColor; }
blockquote.blockquote-tag-note .blockquote-tag-title { color: var(--blockquote-note-color); }
blockquote.blockquote-tag-tip .blockquote-tag-title { color: var(--blockquote-tip-color); }
blockquote.blockquote-tag-important .blockquote-tag-title { color: var(--blockquote-important-color); }
blockquote.blockquote-tag-warning .blockquote-tag-title { color: var(--blockquote-warning-color); }
blockquote.blockquote-tag-caution .blockquote-tag-title { color: var(--blockquote-caution-color); }

/* ---- Mermaid ----------------------------------------------------------- */

.mermaid {
    text-align: center;
    margin: 1.5rem 0;
    overflow-x: auto;
}

.mermaid svg {
    max-width: 100%;
    height: auto;
}

/* ---- Sidebar ----------------------------------------------------------- */

.sidebar {
    font-size: 0.9rem;
    border-right: 1px solid var(--chatty-rule);
}

.sidebar .sidebar-scrollbox {
    padding: 0.75rem 0.5rem 2rem 1rem;
}

.chapter li.part-title {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--chatty-muted);
    margin: 1.5rem 0 0.4rem;
}

.chapter li.part-title:first-child {
    margin-top: 0.25rem;
}

.chapter li.chapter-item {
    margin-top: 0.15rem;
    line-height: 1.5;
}

.chapter li a,
.chapter li > div {
    padding: 0.2rem 0.5rem;
    border-radius: 6px;
    display: block;
    color: var(--sidebar-fg);
}

.chapter li a:hover {
    background: var(--theme-hover);
    color: var(--fg);
    text-decoration: none;
}

.chapter li a.active {
    background: var(--chatty-accent-soft);
    color: var(--sidebar-active);
    font-weight: 500;
}

.chapter li > ol {
    margin-left: 0.75rem;
    border-left: 1px solid var(--chatty-rule);
    padding-left: 0.5rem;
}

.chapter .section li a {
    font-size: 0.86rem;
}

.sidebar .sidebar-resize-handle {
    background: transparent;
}

.sidebar hr,
.chapter .spacer {
    border-color: var(--chatty-rule);
}

/* ---- Menu bar / header ------------------------------------------------ */

#mdbook-menu-bar,
.menu-bar {
    border-bottom: 1px solid var(--chatty-rule);
    background: var(--bg);
}

.menu-bar .menu-title {
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.menu-bar .menu-title a {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--fg);
    text-decoration: none;
}

.menu-bar .menu-title img {
    width: 22px;
    height: 22px;
    border-radius: 6px;
}

.menu-bar .icon-button {
    color: var(--icons);
    border-radius: 6px;
}

.menu-bar .icon-button:hover {
    color: var(--icons-hover);
    background: var(--theme-hover);
}

.theme-popup {
    border-radius: 8px;
    box-shadow: var(--chatty-shadow);
}

/* ---- Search ------------------------------------------------------------ */

#mdbook-searchbar,
#searchbar {
    border-radius: 8px;
    padding: 0.6rem 0.9rem;
    font-family: inherit;
}

#mdbook-searchbar:focus,
#searchbar:focus {
    outline: 2px solid var(--chatty-accent);
    outline-offset: 1px;
    box-shadow: none;
}

.searchresults-outer li {
    border-radius: 6px;
}

/* ---- Page navigation --------------------------------------------------- */

.nav-chapters {
    color: var(--icons);
}

.nav-chapters:hover {
    background: transparent;
    color: var(--chatty-accent);
}

/* ---- Home page --------------------------------------------------------- */

.home-hero {
    margin: 1rem 0 1.5rem;
}

.home-hero p.lede {
    font-size: 1.2rem;
    color: var(--chatty-muted);
    max-width: 44ch;
    text-wrap: balance;
}

.hero-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    margin: 1.25rem 0 2rem;
}

.hero-links a {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    background: var(--chatty-accent);
    color: #fff !important;
    text-decoration: none;
    font-weight: 500;
    border: 1px solid var(--chatty-accent);
}

.hero-links a.secondary {
    background: var(--chatty-surface);
    color: var(--fg) !important;
    border-color: var(--chatty-rule);
}

.hero-links a:hover {
    filter: brightness(1.05);
    border-bottom-color: var(--chatty-accent);
}

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.9rem;
    margin: 1.25rem 0 2rem;
}

.cards a.card {
    display: block;
    padding: 1rem 1.1rem;
    background: var(--chatty-surface);
    border: 1px solid var(--chatty-rule);
    border-radius: 10px;
    color: var(--fg);
    text-decoration: none;
    transition: border-color 0.12s ease, transform 0.12s ease;
}

.cards a.card:hover {
    border-color: var(--chatty-accent);
    transform: translateY(-1px);
}

.cards .card .eyebrow {
    display: block;
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--chatty-accent);
    margin-bottom: 0.35rem;
}

.cards .card strong {
    display: block;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.cards .card span {
    font-size: 0.9rem;
    color: var(--chatty-muted);
}

/* ---- Responsive -------------------------------------------------------- */

@media (max-width: 720px) {
    :root { --page-padding: 16px; }
    .content h1 { font-size: 1.7rem; }
    .content h2 { font-size: 1.3rem; }
    .content table { font-size: 0.85rem; }
}

@media (prefers-reduced-motion: reduce) {
    .content a, .cards a.card, pre > .buttons { transition: none; }
}