/* Mo Paper: the theme of mohoushmand.com.
   A personal variant of the QDaria book system: paper light by default, the old thqai teal-black after dark, TeX Gyre
   Pagella for text, LM Mono for code, square corners, hairline rules and one gradient, the brand hairline.
   No shadows, no pills, no side bars on notes. Sits on top of sphinx-book-theme (pydata-sphinx-theme). */

/* ── Fonts (TeX Gyre and Latin Modern, GUST Font Licence: fonts/*LICENSE.txt) ─────────────────────── */
@font-face { font-family: "TeX Gyre Pagella"; src: url("fonts/pagella-regular.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "TeX Gyre Pagella"; src: url("fonts/pagella-italic.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "TeX Gyre Pagella"; src: url("fonts/pagella-bold.woff2") format("woff2"); font-weight: 700; font-style: normal; font-display: swap; }
@font-face { font-family: "TeX Gyre Pagella"; src: url("fonts/pagella-bolditalic.woff2") format("woff2"); font-weight: 700; font-style: italic; font-display: swap; }
@font-face { font-family: "TeX Gyre Pagella Math"; src: url("fonts/pagella-math.woff2") format("woff2"); font-display: swap; }
@font-face { font-family: "TeX Gyre Chorus"; src: url("fonts/chorus-mediumitalic.woff2") format("woff2"); font-weight: 500; font-style: italic; font-display: swap; }
@font-face { font-family: "LM Mono"; src: url("fonts/lmmono-regular.woff2") format("woff2"); font-display: swap; }

/* ── Tokens ─────────────────────────────────────────────────────────────────────────────────────── */
:root {
  --mo-font-text: "TeX Gyre Pagella", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --mo-font-math: "TeX Gyre Pagella Math", "TeX Gyre Pagella", math, serif;
  --mo-font-name: "TeX Gyre Chorus", "TeX Gyre Pagella", cursive;
  --mo-font-code: "LM Mono", ui-monospace, Menlo, monospace;
  --mo-hairline: linear-gradient(90deg, #0BBFD6, #115BCD 50%, #7C3AED);
  --mo-measure: 72ch;
  --mo-label: 0.8125rem;
  --mo-caption: 0.9375rem;

  --pst-font-family-base: var(--mo-font-text);
  --pst-font-family-heading: var(--mo-font-text);
  --pst-font-family-monospace: var(--mo-font-code);
  --pst-font-size-base: 1.125rem;
  --pst-font-weight-heading: 400;
  --pst-admonition-font-weight-heading: 400;
}

html[data-theme="light"] {
  color-scheme: light;
  --mo-paper: #FFFBF2;
  --mo-paper-edge: #F7E9C9;
  --mo-ground: radial-gradient(120% 90% at 50% 0%, #FFFBF2 0%, #FFFBF2 35%, #F7E9C9 100%);
  --mo-surface: #FFFDF9;
  --mo-rule: #E2CFA4;
  --mo-ink: #14182B;
  --mo-muted: #5F6679;
  --mo-muted-strong: #474D5E;
  --mo-halfgray: #827C76;
  --mo-saffron: #E3A018;
  --mo-saffron-text: #874E0D;
  --mo-blue: #115BCD;
  --mo-violet: #7C3AED;
  --mo-link: #97142F;           /* maroon, darkened from #AD1737 to reach 7:1 on the paper edge */
  --mo-focus: #115BCD;
  --mo-texture-opacity: 0.03;
  --mo-texture-blend: multiply;
}

html[data-theme="dark"] {
  /* The old thqai dark palette (Mo, 7 Oct 2026: "the older dark mode instead of this umber night"). */
  color-scheme: dark;
  --mo-paper: #13191D;
  --mo-paper-edge: #0B1317;
  --mo-ground: radial-gradient(120% 90% at 50% 0%, #13191D 0%, #13191D 35%, #0B1317 100%);
  --mo-surface: #0F1418;
  --mo-rule: #243138;
  --mo-ink: #E5ECEC;
  --mo-muted: #A6B4B8;
  --mo-muted-strong: #CDD7D9;
  --mo-halfgray: #7D8A90;
  --mo-saffron: #E6B850;
  --mo-saffron-text: #E6B850;
  --mo-blue: #5A98F3;
  --mo-violet: #B9A4F8;
  --mo-link: #2FD3C4;           /* bright teal, 9.5:1 on the ground */
  --mo-focus: #E6B850;
  --mo-texture-opacity: 0.025;
  --mo-texture-blend: soft-light;
}

html[data-theme="light"], html[data-theme="dark"] {
  --pst-color-background: var(--mo-paper);
  --pst-color-on-background: var(--mo-paper);
  --pst-color-surface: var(--mo-surface);
  --pst-color-on-surface: var(--mo-surface);
  --pst-color-text-base: var(--mo-ink);
  --pst-color-text-muted: var(--mo-muted);
  --pst-color-heading: var(--mo-ink);
  --pst-color-primary: var(--mo-ink);
  --pst-color-secondary: var(--mo-saffron-text);
  --pst-color-accent: var(--mo-saffron-text);
  --pst-color-link: var(--mo-link);
  --pst-color-link-hover: var(--mo-link);
  --pst-color-link-higher-contrast: var(--mo-link);
  --pst-color-border: var(--mo-rule);
  --pst-color-border-muted: var(--mo-rule);
  --pst-color-shadow: transparent;
  --pst-color-inline-code: var(--mo-ink);
  --pst-color-target: var(--mo-surface);
  --pst-color-table-row-zebra-low-bg: transparent;
  --pst-color-table-row-zebra-high-bg: transparent;
  --pst-color-table-row-hover-bg: transparent;
  --pst-color-table-heading-bg: transparent;
  --pst-color-table-inner-border: var(--mo-rule);
  --pst-color-table-outer-border: var(--mo-ink);
  --pst-color-blockquote-notch: var(--mo-rule);
  --pst-color-info: var(--mo-ink);
  --pst-color-info-bg: transparent;
  --pst-color-success: var(--mo-blue);
  --pst-color-success-bg: transparent;
  --pst-color-attention: var(--mo-saffron-text);
  --pst-color-attention-bg: transparent;
  --pst-color-warning: var(--mo-link);
  --pst-color-warning-bg: transparent;
  --pst-color-danger: var(--mo-link);
  --pst-color-danger-bg: transparent;
  --pst-sd-dropdown-color: var(--mo-ink);
  --pst-sd-dropdown-bg-color: transparent;
  --mystnb-source-bg-color: var(--mo-surface);
  --mystnb-source-border-color: var(--mo-rule);
  --mystnb-source-margin-color: var(--mo-rule);
  --mystnb-source-border-width: 0.5px;
  --mystnb-source-border-radius: 0;
  --mystnb-stdout-bg-color: transparent;
  --mystnb-stdout-border-color: var(--mo-rule);
  --mystnb-stderr-bg-color: transparent;
  --mystnb-stderr-border-color: var(--mo-link);
  --mystnb-traceback-bg-color: transparent;
  --mystnb-traceback-border-color: var(--mo-link);
}

/* ── Ground and type ────────────────────────────────────────────────────────────────────────────── */
html { background-color: var(--mo-paper-edge); background-image: var(--mo-ground); background-attachment: fixed; }
body {
  position: relative; isolation: isolate;
  background: var(--mo-ground); background-attachment: fixed; color: var(--mo-ink);
  font-family: var(--mo-font-text); line-height: 1.55;
  font-variant-numeric: oldstyle-nums proportional-nums;
  font-feature-settings: "liga", "kern";
}
body::before {
  content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background: url("paper.svg") repeat; opacity: var(--mo-texture-opacity); mix-blend-mode: var(--mo-texture-blend);
}
.bd-container, .bd-main, .bd-page-width, .bd-article-container, .bd-footer, .bd-footer-content { background: transparent; }
/* The sidebars sit on the paper ground on wide screens; on phones pydata moves them into modal dialogs,
   which need a solid paper. The article header is sticky, so text must not scroll through it. */
@media (min-width: 960px) { .bd-sidebar-primary, .bd-sidebar-secondary { background: transparent; } }
@media (max-width: 959.98px) { .bd-sidebar-primary, .bd-sidebar-secondary { background: var(--mo-paper); } }
#pst-primary-sidebar-modal, #pst-secondary-sidebar-modal, #pst-search-dialog { background: var(--mo-paper); color: var(--mo-ink); border: 0.5px solid var(--mo-rule); border-radius: 0; }
#pst-primary-sidebar-modal::backdrop, #pst-secondary-sidebar-modal::backdrop, #pst-search-dialog::backdrop { background: color-mix(in srgb, var(--mo-ink) 35%, transparent); }
.bd-header-article { background: var(--mo-paper); }
/* pydata 0.17 renders its own top navbar under sphinx-book-theme 1.3; it only repeats the search button,
   and the article header already carries the menu toggle, so it is hidden. */
#pst-header { display: none; }
/* Bootstrap's rounded-pill is !important; the back-to-top button stays square. */
#pst-back-to-top { border-radius: 0 !important; box-shadow: none; background: var(--mo-ink); color: var(--mo-paper); border: 0; }
::selection { background: color-mix(in srgb, var(--mo-saffron) 25%, var(--mo-paper)); color: var(--mo-ink); }
:focus-visible { outline: 2px solid var(--mo-focus); outline-offset: 2px; box-shadow: none; }

.bd-article p, .bd-article li { max-width: var(--mo-measure); }
.bd-article h1 {
  font-size: clamp(2.25rem, 4.6vw, 3.5rem); line-height: 1.06; font-weight: 400; letter-spacing: 0;
  margin: 0.5rem 0 1.5rem;
}
.bd-article h1::after { content: ""; display: block; width: 64px; height: 2px; margin-top: 1.5rem; background: var(--mo-hairline); }
.bd-article h2 {
  font-size: 1.75rem; line-height: 1.15; font-weight: 400; font-variant-caps: small-caps; letter-spacing: 0.08em;
  margin: 3rem 0 1rem;
}
.bd-article h3 { font-size: 1.375rem; line-height: 1.2; font-weight: 400; margin: 2.25rem 0 0.75rem; }
.bd-article h4, .bd-article h5 { font-size: 1.125rem; font-weight: 700; margin: 1.75rem 0 0.5rem; }
.bd-article .section-number { color: var(--mo-muted); margin-right: 0.4em; font-variant-numeric: lining-nums tabular-nums; }
.bd-article strong, .bd-article b { font-weight: 700; }
.bd-article blockquote {
  margin: 1.5rem 0; padding: 0 0 0 2rem; border: 0; background: transparent;
  font-style: italic; color: var(--mo-muted-strong);
}
.bd-article blockquote::before { display: none; }
.bd-article hr { border: 0; border-top: 0.5px solid var(--mo-rule); opacity: 1; margin: 2.5rem 0; }
.bd-article .math, .bd-article mjx-container { font-family: var(--mo-font-math); }

a { color: var(--mo-link); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 0.15em; }
a:hover { color: var(--mo-link); text-decoration-thickness: 2px; }

.mo-lead { font-size: 1.3125rem; line-height: 1.45; max-width: var(--mo-measure); margin-bottom: 2rem; }
.mo-lead p { max-width: none; }

/* ── Sidebar, header and navigation ─────────────────────────────────────────────────────────────── */
.bd-sidebar-primary { border-right: 0.5px solid var(--mo-rule); font-size: var(--mo-caption); }
.navbar-brand { gap: 0.75rem; align-items: center; }
.navbar-brand img { height: 2.25rem; width: auto; border-radius: 0; }
.navbar-brand .title, .navbar-brand p.title {
  font-family: var(--mo-font-name); font-style: italic; font-weight: 500; font-size: 1.45rem; color: var(--mo-ink);
}
.bd-links { padding-top: 0.5rem; }
.bd-links .caption, .bd-links p.caption, .bd-links .caption-text {
  font-family: var(--mo-font-text); font-size: var(--mo-label); font-weight: 400; color: var(--mo-ink);
  font-variant-caps: all-small-caps; letter-spacing: 0.16em; text-transform: none;
}
.bd-links p.caption { margin-top: 1.5rem; margin-bottom: 0.25rem; }
.bd-links a, .bd-links .reference {
  color: var(--mo-muted); text-decoration: none; border-radius: 0; box-shadow: none !important;
}
.bd-links a:hover { color: var(--mo-ink); text-decoration: underline; background: transparent; }
.bd-links .current > a, .bd-links a.current {
  position: relative; color: var(--mo-ink); font-weight: 400; background: transparent;
  box-shadow: none !important;
}
.bd-links .current > a::before, .bd-links a.current::before {
  content: ""; position: absolute; left: -0.6rem; top: calc(50% - 8px); width: 2px; height: 16px; background: var(--mo-saffron);
}
.bd-sidebar-primary .sidebar-primary-items__end, .bd-sidebar-primary .bd-sidebar__bottom { display: none; }
nav.bd-links li > a:focus-visible, .bd-links a:focus-visible, .toc-entry a.nav-link:focus-visible { outline: 2px solid var(--mo-focus); outline-offset: 2px; }

.bd-header-article { border-bottom: 0.5px solid var(--mo-rule); }
.bd-header-article .btn, .article-header-buttons .btn, .theme-switch-button {
  border-radius: 0; box-shadow: none; color: var(--mo-ink); background: transparent;
}
.bd-header-article .btn:hover, .theme-switch-button:hover { color: var(--mo-link); background: transparent; }
.dropdown-menu { border-radius: 0; border: 0.5px solid var(--mo-rule); box-shadow: none; background: var(--mo-paper); }
.bd-article kbd, .search-button-field kbd, .kbd-shortcut__modifier, kbd { border-radius: 0; box-shadow: none; }
.search-button-field:focus-visible, .search-button-field:hover { border-radius: 0; }
.bd-search, .search-button-field, .bd-search input {
  border-radius: 0; box-shadow: none; border-color: var(--mo-rule); background: var(--mo-surface); color: var(--mo-ink);
}
.search-button__wrapper.show .search-button__search-container, .bd-search-container { border-radius: 0; box-shadow: none; }

.bd-sidebar-secondary { font-size: var(--mo-caption); }
.bd-sidebar-secondary .onthispage, .bd-sidebar-secondary .tocsection {
  font-variant-caps: all-small-caps; letter-spacing: 0.16em; color: var(--mo-ink); font-weight: 400;
}
.bd-toc-nav, .toc-entry a.nav-link { border-left-color: var(--mo-rule); }
.toc-entry a.nav-link { color: var(--mo-muted); }
.toc-entry a.nav-link:hover { color: var(--mo-ink); }
.toc-entry a.nav-link.active { color: var(--mo-ink); font-weight: 400; border-left-color: var(--mo-saffron); background: transparent; box-shadow: none; }

.prev-next-area { border-top: 0.5px solid var(--mo-rule); padding-top: 1.5rem; margin-top: 3rem; }
.prev-next-area a, .prev-next-area a p.prev-next-title { color: var(--mo-link); }
.prev-next-area a .prev-next-subtitle { color: var(--mo-ink); font-variant-caps: all-small-caps; letter-spacing: 0.12em; }
.prev-next-area i, .prev-next-area svg { display: none; }
.bd-footer-content { border-top: 0.5px solid var(--mo-rule); color: var(--mo-muted); font-size: var(--mo-caption); }

/* ── Notes (amsthm style: a top hairline and a kicker, never a side bar) ────────────────────────── */
.bd-article .admonition, .bd-article div.admonition, .bd-article .topic {
  border: 0; border-top: 0.5px solid var(--mo-rule); border-radius: 0; box-shadow: none !important;
  background: transparent; padding: 1rem 0 0; margin: 2rem 0; overflow: visible;
}
.bd-article .admonition > .admonition-title, .bd-article div.admonition > p.admonition-title {
  background: transparent; color: var(--mo-ink); margin: 0 0 0.75rem; padding: 0; font-size: var(--mo-label);
  font-weight: 400; font-variant-caps: all-small-caps; letter-spacing: 0.12em; position: relative;
}
.bd-article .admonition > .admonition-title::before, .bd-article .admonition > .admonition-title::after { content: none; display: none; }
.bd-article .admonition > *:last-child { margin-bottom: 0; }
.bd-article .admonition > :not(.admonition-title) { margin-left: 0; margin-right: 0; }
.bd-article .admonition:is(.warning, .danger, .error, .caution) { border-top: 1px solid var(--mo-link); }
.bd-article .admonition:is(.warning, .danger, .error, .caution) > .admonition-title { color: var(--mo-link); }
.bd-article .admonition:is(.important, .attention) > .admonition-title { color: var(--mo-saffron-text); }
.bd-article .admonition:is(.tip, .hint) > .admonition-title { color: var(--mo-blue); }
.bd-article .admonition.mo-source { font-size: var(--mo-caption); color: var(--mo-muted-strong); }
.bd-article .admonition.mo-source > .admonition-title { color: var(--mo-muted); }
/* Dropdown notes (sphinx-togglebutton) keep their toggle as a plain small-caps control. */
.bd-article .admonition.dropdown > .admonition-title { cursor: pointer; padding-right: 2rem; }
.bd-article .toggle-button, .bd-article button.toggle-button { color: var(--mo-ink); }
.bd-article .toggle-button svg { stroke: currentColor; }
.bd-article button.toggle-button:focus-visible, .bd-article .admonition.dropdown > .admonition-title:focus-visible { outline: 2px solid var(--mo-focus); outline-offset: 2px; }

/* ── Cards, figures, tables ─────────────────────────────────────────────────────────────────────── */
.sd-card { border: 0.5px solid var(--mo-rule); border-radius: 0; background: transparent; box-shadow: none !important; }
.sd-card-header, .sd-card-footer { background: transparent; border-color: var(--mo-rule); }
.sd-shadow-sm, .sd-shadow-md, .sd-shadow-lg { box-shadow: none !important; }
.sd-card-img-top, .sd-card-img { border-radius: 0; }
.bd-article img { border-radius: 0; }
.bd-article figure { margin: 1.5rem 0 2rem; }
.bd-article figcaption, .bd-article figure .caption, .bd-article figure .caption-text {
  font-size: var(--mo-caption); line-height: 1.45; color: var(--mo-muted); text-align: left; margin-top: 0.75rem;
}
.bd-article figcaption p { max-width: var(--mo-measure); }
.mo-plates figure { margin: 0; }
.mo-plates img { width: 100%; height: auto; border: 0.5px solid var(--mo-rule); }
.mo-portrait img { width: 100%; max-width: 22rem; height: auto; border: 0.5px solid var(--mo-rule); }
.mo-intro ul { padding-left: 1.1rem; }
html[data-theme="dark"] .bd-content img:not(.only-dark):not(.dark-light) { border-radius: 0; }
html[data-theme="dark"] .bd-content :is(.mo-plates, .mo-portrait) img { filter: none; background: transparent; }
.bd-article .admonition-title, .bd-article .sd-card-title, .bd-article .sd-card-header,
html[data-theme="dark"] .bd-article .admonition-title, html[data-theme="dark"] .bd-article .sd-card-title,
html[data-theme="dark"] .bd-article .sd-card-header, html[data-theme="dark"] .bd-article .admonition > .admonition-title { text-shadow: none; }

.bd-article table, .bd-article table.table {
  border-collapse: collapse; border-top: 1px solid var(--mo-ink); border-bottom: 1px solid var(--mo-ink);
  font-size: var(--mo-caption); line-height: 1.45; font-variant-numeric: lining-nums tabular-nums; background: transparent;
}
.bd-article table thead th, .bd-article table.table thead th {
  border: 0; border-bottom: 0.5px solid var(--mo-ink); background: transparent; color: var(--mo-ink); font-weight: 400;
  font-variant-caps: all-small-caps; letter-spacing: 0.05em; text-align: left; vertical-align: bottom; padding: 0.5rem 0.75rem;
}
.bd-article table td, .bd-article table tbody th {
  border: 0; border-bottom: 0.5px solid var(--mo-rule); background: transparent; padding: 0.5rem 0.75rem; vertical-align: top;
}
.bd-article table tbody tr:last-child > * { border-bottom: 0; }
.bd-article table tbody tr:hover > * { background: transparent; }

.bd-article .toctree-wrapper p.caption, .bd-article .toctree-wrapper .caption-text {
  margin: 1.5rem 0 0.25rem; font-size: var(--mo-label); color: var(--mo-ink); text-align: left;
  font-variant-caps: all-small-caps; letter-spacing: 0.16em;
}
.bd-article .epigraph { border: 0; padding: 0; margin: 3rem 0 1rem; font-style: italic; color: var(--mo-muted-strong); }

/* ── Code and notebook cells ────────────────────────────────────────────────────────────────────── */
.bd-article code, .bd-article kbd, .bd-article samp, .bd-article pre { font-family: var(--mo-font-code); font-variant-numeric: lining-nums tabular-nums; }
.bd-article code.literal, .bd-article p code, .bd-article li code {
  background: transparent; border: 0; padding: 0; font-size: 0.92em; color: var(--mo-ink);
}
html[data-theme] .bd-article div.highlight, html[data-theme] .bd-article .highlight, .bd-article div[class*="highlight-"] {
  background: var(--mo-surface); border-radius: 0; box-shadow: none;
}
.bd-article div[class*="highlight-"] { border-block: 0.5px solid var(--mo-rule); margin: 1.5rem 0; }
html[data-theme] .bd-article .highlight pre { background: transparent; border: 0; border-radius: 0; box-shadow: none; padding: 1rem; font-size: 0.95rem; line-height: 1.6; color: var(--mo-ink); }
.bd-article .copybtn { border-radius: 0; box-shadow: none; background: var(--mo-paper); border: 0.5px solid var(--mo-rule); }
.bd-article div.cell div.cell_input, .bd-article div.cell_input {
  border: 0; border-block: 0.5px solid var(--mo-rule); border-radius: 0; background: var(--mo-surface);
}
.bd-article div.cell div.cell_output, .bd-article div.cell_output { padding-left: 0; }
.bd-article div.cell_output .output pre, .bd-article div.output pre { background: transparent; border: 0; border-left: 0; }
.bd-article div.cell_output img { max-width: 100%; }

/* Code colours from the brand tokens, in both themes. */
html[data-theme] .highlight .c, html[data-theme] .highlight .c1, html[data-theme] .highlight .cm, html[data-theme] .highlight .ch, html[data-theme] .highlight .cs, html[data-theme] .highlight .cp, html[data-theme] .highlight .cpf { color: var(--mo-muted); font-style: italic; }
html[data-theme] .highlight .k, html[data-theme] .highlight .kn, html[data-theme] .highlight .kd, html[data-theme] .highlight .kc, html[data-theme] .highlight .kr, html[data-theme] .highlight .kt, html[data-theme] .highlight .kp, html[data-theme] .highlight .ow { color: var(--mo-violet); font-weight: 400; }
html[data-theme] .highlight .s, html[data-theme] .highlight .s1, html[data-theme] .highlight .s2, html[data-theme] .highlight .sd, html[data-theme] .highlight .se, html[data-theme] .highlight .sa, html[data-theme] .highlight .sb, html[data-theme] .highlight .si, html[data-theme] .highlight .sh, html[data-theme] .highlight .sx, html[data-theme] .highlight .sr, html[data-theme] .highlight .ss, html[data-theme] .highlight .dl { color: var(--mo-saffron-text); }
html[data-theme] .highlight .m, html[data-theme] .highlight .mi, html[data-theme] .highlight .mf, html[data-theme] .highlight .mh, html[data-theme] .highlight .mo, html[data-theme] .highlight .il, html[data-theme] .highlight .mb { color: var(--mo-blue); }
html[data-theme] .highlight .nf, html[data-theme] .highlight .fm, html[data-theme] .highlight .nc, html[data-theme] .highlight .nn { color: var(--mo-blue); }
html[data-theme] .highlight .nb, html[data-theme] .highlight .bp, html[data-theme] .highlight .nd { color: var(--mo-link); }
html[data-theme] .highlight .n, html[data-theme] .highlight .nx, html[data-theme] .highlight .na, html[data-theme] .highlight .nv, html[data-theme] .highlight .p, html[data-theme] .highlight .o, html[data-theme] .highlight .w, html[data-theme] .highlight .err { color: var(--mo-ink); background: transparent; }
html[data-theme] .highlight .gp, html[data-theme] .highlight .go { color: var(--mo-muted); }

/* ── Buttons and controls ───────────────────────────────────────────────────────────────────────── */
.btn, .sd-btn, button { border-radius: 0; box-shadow: none; }
.sd-btn, .bd-article .btn { border: 1px solid var(--mo-ink); color: var(--mo-ink); background: transparent; font-variant-caps: all-small-caps; letter-spacing: 0.12em; }
.bd-article details.sd-dropdown { border: 0; border-top: 0.5px solid var(--mo-rule); border-radius: 0; box-shadow: none !important; }
.bd-article details.sd-dropdown summary { background: transparent; color: var(--mo-ink); }
.bd-article .tab-set > label, .bd-article .sd-tab-set > label { border-radius: 0; color: var(--mo-muted); font-variant-caps: all-small-caps; letter-spacing: 0.12em; }
.bd-article .tab-set > input:checked + label, .bd-article .sd-tab-set > input:checked + label { color: var(--mo-ink); border-color: var(--mo-ink); }

/* ── Restored 2023 features, in the paper style ─────────────────────────────────────────────── */
/* Picture plates: the 2023 image cards, now square with a hairline frame and no shadow. */
.bd-article .sd-card.mo-plate { border: 0.5px solid var(--mo-rule); background: var(--mo-surface); margin: 1.5rem 0; }
.bd-article .sd-card.mo-plate .sd-card-body { padding: 0.75rem; }
.bd-article .sd-card.mo-plate img { display: block; margin: 0 auto; max-width: 100%; height: auto; }

/* "+" toggles: dropdown notes, solutions and sphinx-design dropdowns open with + and close with −. */
.bd-article .toggle-button .tb-icon, .bd-article details.sd-dropdown .sd-summary-state-marker svg,
.bd-article details.sd-dropdown .sd-summary-chevron-right, .bd-article details.sd-dropdown .sd-summary-chevron-down { display: none; }
.bd-article .toggle-button::after { content: "+"; font: 400 1.25rem/1 var(--mo-font-text); color: var(--mo-ink); }
.bd-article .toggle-button.toggle-button-hidden::after { content: "+"; }
.bd-article .toggle-button:not(.toggle-button-hidden)::after { content: "−"; }
.bd-article details.sd-dropdown > summary::after { content: "+"; margin-left: auto; font: 400 1.25rem/1 var(--mo-font-text); color: var(--mo-ink); }
.bd-article details.sd-dropdown[open] > summary::after { content: "−"; }
.bd-article details.sd-dropdown > summary { display: flex; align-items: center; gap: 0.75rem; list-style: none; padding: 0.75rem 0; font-variant-caps: small-caps; letter-spacing: 0.06em; }
.bd-article details.sd-dropdown > summary::-webkit-details-marker { display: none; }

/* Tabs (framework panels): underlined labels, never pills. */
.bd-article .sd-tab-set { margin: 1.5rem 0; border-top: 0.5px solid var(--mo-rule); }
.bd-article .sd-tab-set > label {
  border: 0; border-bottom: 2px solid transparent; border-radius: 0; background: transparent; padding: 0.6rem 0.9rem;
  color: var(--mo-muted); font-variant-caps: all-small-caps; letter-spacing: 0.12em; font-weight: 400;
}
.bd-article .sd-tab-set > input:checked + label { color: var(--mo-ink); border-bottom-color: var(--mo-ink); }
.bd-article .sd-tab-set > input:focus-visible + label { outline: 2px solid var(--mo-focus); outline-offset: 2px; }
.bd-article .sd-tab-content { border: 0; border-top: 0.5px solid var(--mo-rule); padding: 1rem 0 0; box-shadow: none; }

/* Badges: square text labels with a hairline, as the brand's registers. */
.bd-article .mo-badge, .bd-article .sd-badge {
  display: inline-block; padding: 0.15rem 0.5rem; border: 0.5px solid var(--mo-rule); border-radius: 0;
  background: transparent; color: var(--mo-ink); font-size: var(--mo-label); font-variant-caps: all-small-caps;
  letter-spacing: 0.12em; text-decoration: none; margin: 0 0.4rem 0.4rem 0;
}
.bd-article a.mo-badge:hover { border-color: var(--mo-ink); }

/* Checklists: square boxes in ink. */
.bd-article .task-list-item { list-style: none; }
.bd-article .task-list-item-checkbox { appearance: none; width: 0.9em; height: 0.9em; margin: 0 0.5em 0 -1.4em; border: 1px solid var(--mo-ink); border-radius: 0; vertical-align: -0.05em; }
.bd-article .task-list-item-checkbox:checked { background: var(--mo-ink); box-shadow: inset 0 0 0 2px var(--mo-paper); }

/* Paragraph headings (#####) read in, unnumbered: the fifth level of the book. */
.bd-article h5, .bd-article h6 { font-size: 1.125rem; font-weight: 700; font-style: italic; margin: 1.5rem 0 0.25rem; }
.bd-article h5 .section-number, .bd-article h6 .section-number { display: none; }

/* Home page: profile card, welcome line and motto. */
.bd-article .mo-profile .sd-card-img-top { max-height: 9rem; object-fit: cover; filter: grayscale(1) sepia(0.35) brightness(1.08) contrast(0.8); }
html[data-theme="dark"] .bd-article .mo-profile .sd-card-img-top { filter: grayscale(1) sepia(0.5) brightness(0.45) contrast(0.9); }
.bd-article .mo-profile .sd-card-header { border-bottom: 0.5px solid var(--mo-rule); background: transparent; }
.bd-article .mo-profile .mo-portrait img { display: block; margin: 0 auto; }
.bd-article .mo-welcome, .bd-article .mo-motto { text-align: center; font-variant-caps: small-caps; letter-spacing: 0.06em; }
.bd-article .mo-motto { margin: 3rem 0 1rem; font-style: italic; font-variant-caps: normal; letter-spacing: 0; }
.bd-article :is(.mo-welcome, .mo-motto) p { max-width: none; margin-inline: auto; }
.bd-article .sd-card-footer { border-top: 0.5px solid var(--mo-rule); background: transparent; font-size: var(--mo-label); color: var(--mo-muted); }

/* Part numerals in the sidebar: Part I, Part II … on each numbered part's caption. */
.bd-links { counter-reset: mo-part; }
.bd-links p.caption:not(:first-of-type) { counter-increment: mo-part; }
.bd-links p.caption:not(:first-of-type) .caption-text::before { content: "Part " counter(mo-part, upper-roman) " · "; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}
@media print {
  body::before { display: none; }
  .bd-sidebar-primary, .bd-sidebar-secondary, .bd-header-article, .prev-next-area { display: none !important; }
}