:root {
  --header-h: 64px;
  --sidebar-w: 280px;
  --toc-w: 224px;
  --content-max: 880px;

  --bg: #ffffff;
  --bg-subtle: #f7f5fc;
  --bg-hover: #f0ebfb;
  --text: #1b1826;
  --muted: #615c73;
  --border: #e4e0ee;
  --border-strong: #d2cbe3;

  --accent: #5b21b6;
  --accent-strong: #4c1d95;
  --accent-2: #0891b2;
  --accent-soft: #f2ecff;
  --accent-contrast: #ffffff;

  --code-bg: #f7f5fc;
  --code-border: #e4e0ee;
  --pre-bg: #fbfaff;

  --gradient: linear-gradient(112deg, #1b0b3b 0%, #4c1d95 34%, #1d4ed8 70%, #06b6d4 100%);
  --shadow-sm: 0 1px 2px rgba(23, 12, 60, 0.06);
  --shadow-md: 0 10px 30px rgba(23, 12, 60, 0.08);

  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0d14;
    --bg-subtle: #121522;
    --bg-hover: #1a1d2e;
    --text: #e8e7f2;
    --muted: #a3a0b8;
    --border: #242838;
    --border-strong: #333850;

    --accent: #a78bfa;
    --accent-strong: #c4b5fd;
    --accent-2: #22d3ee;
    --accent-soft: #1c1733;
    --accent-contrast: #0b0d14;

    --code-bg: #151828;
    --code-border: #242838;
    --pre-bg: #10131f;

    --gradient: linear-gradient(112deg, #12082b 0%, #3b1280 34%, #143f9c 70%, #0a7f96 100%);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.45);
  }
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  font-feature-settings: "cv11", "ss01";
}

a {
  color: var(--accent);
  text-decoration: none;
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration: underline;
}

:focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 2px;
}

::selection {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 0.5rem 0.75rem;
  z-index: 100;
}

.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

/* Header ------------------------------------------------------------------ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  color: #ffffff;
  background: var(--gradient);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.14) inset, 0 8px 26px rgba(20, 10, 50, 0.2);
  overflow: hidden;
}

.site-header::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(680px 220px at 82% -60%, rgba(255, 255, 255, 0.32), transparent 62%),
    repeating-linear-gradient(115deg, rgba(255, 255, 255, 0.05) 0 1px, transparent 1px 9px);
}

.site-header-inner {
  position: relative;
  z-index: 1;
  max-width: 1440px;
  height: var(--header-h);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #ffffff;
}

.brand:hover {
  text-decoration: none;
}

.brand-icon {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(4px);
}

.brand-icon svg {
  width: 22px;
  height: 22px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.14em;
}

.brand-tagline {
  font-size: 0.72rem;
  color: rgba(255, 255, 255, 0.74);
  letter-spacing: 0.01em;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 12px;
  border-radius: 8px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.14);
  color: #ffffff;
  text-decoration: none;
}

.nav-github {
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.08);
}

.nav-github svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

/* Shell: sidebar + content ------------------------------------------------ */

.page-shell {
  max-width: 1440px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr) var(--toc-w);
  align-items: start;
}

.sidebar {
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
  border-right: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-subtle) 0%, var(--bg) 420px);
}

.sidebar-inner {
  padding: 26px 16px 36px 24px;
  font-size: 0.9rem;
  line-height: 1.5;
}

.sidebar-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 4px;
}

.sidebar-brand {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.sidebar-close {
  display: none;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  padding: 0;
  border: 1px solid var(--border-strong);
  border-radius: 7px;
  background: var(--bg);
  color: var(--muted);
  cursor: pointer;
}

.sidebar-close svg {
  width: 14px;
  height: 14px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
}

.sidebar-heading {
  margin: 20px 0 5px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
}

.sidebar-top + .sidebar-nav > .sidebar-heading,
.sidebar-top + .sidebar-nav > .sidebar-heading:first-child {
  margin-top: 14px;
}

.sidebar-pages {
  margin: 0;
  padding: 0;
  list-style: none;
}

.sidebar-pages a {
  display: block;
  padding: 4px 10px 4px 11px;
  margin: 1px 0;
  border-left: 2px solid transparent;
  border-radius: 0 6px 6px 0;
  color: var(--text);
  font-size: 0.885rem;
  overflow-wrap: anywhere;
}

.sidebar-pages a:hover {
  background: var(--bg-hover);
  color: var(--accent-strong);
  text-decoration: none;
}

.sidebar-pages a[aria-current="page"] {
  background: var(--accent-soft);
  border-left-color: var(--accent);
  color: var(--accent-strong);
  font-weight: 600;
}

.page-toc {
  margin-top: 26px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.toc-rail {
  position: sticky;
  top: var(--header-h);
  max-height: calc(100vh - var(--header-h));
  padding: 44px 24px 40px 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
  font-size: 0.85rem;
  line-height: 1.5;
}

.toc-rail .page-toc {
  margin: 0;
  padding: 0;
  border-top: 0;
}

.toc-rail .sidebar-heading {
  margin: 0 0 8px;
}

.toc-rail .page-toc a {
  font-size: 0.82rem;
}

.page-toc .sidebar-heading {
  margin-top: 0;
}

.page-toc ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-toc a {
  display: block;
  padding: 4px 10px 4px 11px;
  border-left: 2px solid transparent;
  border-radius: 0 6px 6px 0;
  color: var(--muted);
  font-size: 0.83rem;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

.page-toc a:hover {
  background: var(--bg-hover);
  color: var(--accent-strong);
  text-decoration: none;
}

.page-toc a.is-active {
  border-left-color: var(--accent-2);
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-weight: 600;
}

.page-toc .toc-depth-3 {
  padding-left: 24px;
  font-size: 0.79rem;
}

.sidebar-meta {
  margin-top: 28px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.78rem;
}

.sidebar-meta a {
  color: var(--muted);
}

.sidebar-meta a:hover {
  color: var(--accent-strong);
}

.sidebar-toggle {
  display: none;
  position: fixed;
  left: 18px;
  bottom: 18px;
  z-index: 50;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  background: var(--gradient);
  box-shadow: 0 6px 20px rgba(20, 10, 50, 0.35);
  color: #ffffff;
  font: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}

.sidebar-toggle svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
}

body.sidebar-open .sidebar-toggle {
  opacity: 0;
  visibility: hidden;
}

.sidebar-scrim {
  position: fixed;
  inset: 0;
  z-index: 45;
  background: rgba(10, 8, 24, 0.52);
  backdrop-filter: blur(2px);
}

/* Content ----------------------------------------------------------------- */

.site-content {
  width: 100%;
  max-width: var(--content-max);
  min-width: 0;
  justify-self: center;
  padding: 44px 48px 64px;
}

.site-content h1,
.site-content h2,
.site-content h3,
.site-content h4 {
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.02em;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.site-content h1 {
  margin: 0 0 1.4rem;
  font-size: 2.3rem;
  letter-spacing: -0.03em;
}

.site-content h1::after {
  content: "";
  display: block;
  width: 64px;
  height: 4px;
  margin-top: 16px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}

.site-content h2 {
  margin: 2.6rem 0 0.9rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border);
  font-size: 1.5rem;
}

.site-content h3 {
  margin: 2rem 0 0.7rem;
  font-size: 1.17rem;
}

.site-content h4 {
  margin: 1.6rem 0 0.6rem;
  font-size: 1rem;
}

.heading-anchor {
  margin-left: 0.4em;
  color: var(--muted);
  font-weight: 400;
  opacity: 0;
  transition: opacity 0.15s ease;
}

h1:hover .heading-anchor,
h2:hover .heading-anchor,
h3:hover .heading-anchor,
h4:hover .heading-anchor,
.heading-anchor:focus {
  opacity: 0.7;
  text-decoration: none;
}

p,
ul,
ol,
table,
pre,
blockquote,
.mermaid {
  margin: 0 0 1.05rem;
}

ul,
ol {
  padding-left: 1.4rem;
}

li > ul,
li > ol {
  margin-bottom: 0.35rem;
}

li + li {
  margin-top: 0.25rem;
}

strong {
  font-weight: 600;
}

hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 2.2rem 0;
}

blockquote {
  margin-left: 0;
  padding: 0.7rem 1.1rem;
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  background: var(--bg-subtle);
  color: var(--muted);
}

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

img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
}

/* Code -------------------------------------------------------------------- */

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  padding: 0.12em 0.36em;
  border: 1px solid var(--code-border);
  border-radius: 5px;
  background: var(--code-bg);
}

pre {
  padding: 1rem 1.15rem;
  border: 1px solid var(--code-border);
  border-radius: 10px;
  background: var(--pre-bg);
  box-shadow: var(--shadow-sm);
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.6;
}

pre code {
  padding: 0;
  border: 0;
  background: transparent;
  font-size: 1em;
}

.highlight {
  border-radius: 10px;
}

.highlight pre {
  margin: 0;
}

/* Rouge syntax tokens, light theme */
.highlight .c,
.highlight .c1,
.highlight .cm,
.highlight .cs {
  color: #6a737d;
  font-style: italic;
}

.highlight .k,
.highlight .kc,
.highlight .kd,
.highlight .kn,
.highlight .kr,
.highlight .kt,
.highlight .ow {
  color: #d73a49;
}

.highlight .s,
.highlight .s1,
.highlight .s2,
.highlight .sb,
.highlight .sc,
.highlight .sd,
.highlight .se,
.highlight .sh,
.highlight .si,
.highlight .sr,
.highlight .sx {
  color: #032f62;
}

.highlight .m,
.highlight .mb,
.highlight .mf,
.highlight .mh,
.highlight .mi,
.highlight .il {
  color: #005cc5;
}

.highlight .nc,
.highlight .nn,
.highlight .nf,
.highlight .fm,
.highlight .nd,
.highlight .na {
  color: #6f42c1;
}

.highlight .nb,
.highlight .bp,
.highlight .nv,
.highlight .vi {
  color: #005cc5;
}

.highlight .nt {
  color: #22863a;
}

.highlight .o,
.highlight .p {
  color: #24292e;
}

.highlight .gd {
  color: #b31d28;
  background: #ffeef0;
}

.highlight .gi {
  color: #22863a;
  background: #f0fff4;
}

@media (prefers-color-scheme: dark) {
  .highlight .c,
  .highlight .c1,
  .highlight .cm,
  .highlight .cs {
    color: #8b949e;
  }

  .highlight .k,
  .highlight .kc,
  .highlight .kd,
  .highlight .kn,
  .highlight .kr,
  .highlight .kt,
  .highlight .ow {
    color: #ff7b72;
  }

  .highlight .s,
  .highlight .s1,
  .highlight .s2,
  .highlight .sb,
  .highlight .sc,
  .highlight .sd,
  .highlight .se,
  .highlight .sh,
  .highlight .si,
  .highlight .sr,
  .highlight .sx {
    color: #a5d6ff;
  }

  .highlight .m,
  .highlight .mb,
  .highlight .mf,
  .highlight .mh,
  .highlight .mi,
  .highlight .il {
    color: #79c0ff;
  }

  .highlight .nc,
  .highlight .nn,
  .highlight .nf,
  .highlight .fm,
  .highlight .nd,
  .highlight .na {
    color: #d2a8ff;
  }

  .highlight .nb,
  .highlight .bp,
  .highlight .nv,
  .highlight .vi {
    color: #79c0ff;
  }

  .highlight .nt {
    color: #7ee787;
  }

  .highlight .o,
  .highlight .p {
    color: #c9d1d9;
  }

  .highlight .gd {
    color: #ffdcd7;
    background: #67060c;
  }

  .highlight .gi {
    color: #aff5b4;
    background: #033a16;
  }
}

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

table {
  display: block;
  width: 100%;
  max-width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
  font-size: 0.92rem;
  line-height: 1.55;
}

th,
td {
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--bg-subtle);
  font-weight: 600;
}

tbody tr:nth-child(even) {
  background: var(--bg-subtle);
  background: color-mix(in srgb, var(--bg-subtle) 55%, transparent);
}

.mermaid {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-subtle);
  text-align: center;
  overflow-x: auto;
}

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

/* Page meta and footer ---------------------------------------------------- */

.page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 3.5rem;
  padding-top: 1.2rem;
  border-top: 1px dashed var(--border-strong);
  color: var(--muted);
  font-size: 0.85rem;
}

.page-meta a {
  color: var(--muted);
}

.page-meta a:hover {
  color: var(--accent-strong);
}

.site-footer {
  position: relative;
  border-top: 1px solid var(--border);
  background: var(--bg-subtle);
  color: var(--muted);
  font-size: 0.88rem;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  opacity: 0.85;
}

.site-footer p {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.3rem 24px;
}

.site-footer a {
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 0.18em;
}

.site-footer a:hover {
  color: var(--accent-strong);
}

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

@media (max-width: 1199px) {
  .page-shell {
    grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  }

  .toc-rail {
    display: none;
  }

  .site-content {
    padding-left: 36px;
    padding-right: 36px;
  }

  /* Without the right rail, keep the page TOC reachable at the top of the
     sidebar instead of burying it under the whole manual. */
  .sidebar-inner {
    display: flex;
    flex-direction: column;
  }

  .sidebar-top {
    order: 0;
  }

  #toc-slot-sidebar {
    order: 1;
  }

  .sidebar-nav {
    order: 2;
  }

  .sidebar-meta {
    order: 3;
  }

  #toc-slot-sidebar .page-toc {
    margin-top: 14px;
    padding-bottom: 4px;
    border-top: 0;
    border-bottom: 1px solid var(--border);
  }
}

@media (min-width: 1200px) {
  #toc-slot-sidebar {
    display: none;
  }
}

@media (max-width: 1023px) {
  :root {
    --header-h: 58px;
  }

  .page-shell {
    display: block;
  }

  .site-content {
    max-width: none;
    padding: 30px 22px 60px;
  }

  .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 46;
    width: min(86vw, 330px);
    height: 100vh;
    border-right: 1px solid var(--border);
    background: var(--bg);
    box-shadow: var(--shadow-md);
    transform: translateX(-100%);
    transition: transform 0.22s ease;
  }

  .sidebar.is-open {
    transform: none;
  }

  .sidebar-inner {
    padding: 20px 16px 32px 20px;
  }

  .sidebar-close {
    display: inline-flex;
  }

  .sidebar-toggle {
    display: inline-flex;
  }

  body.sidebar-open {
    overflow: hidden;
  }
}

@media (max-width: 720px) {
  .brand-tagline,
  .nav-link:not(.nav-github) {
    display: none;
  }

  .site-header-inner {
    padding: 0 16px;
  }

  .site-content h1 {
    font-size: 1.85rem;
  }

  .site-content h2 {
    font-size: 1.32rem;
  }

  .site-content {
    padding: 26px 18px 56px;
  }

  .site-footer p {
    padding-bottom: 84px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .sidebar {
    transition: none;
  }
}

@media print {
  .site-header::after,
  .top-nav,
  .sidebar,
  .toc-rail,
  .sidebar-toggle,
  .sidebar-scrim,
  .page-meta,
  .site-footer::before {
    display: none !important;
  }

  .site-header {
    position: static;
    background: none;
    color: #000;
    box-shadow: none;
  }

  .brand {
    color: #000;
  }

  .brand-tagline {
    color: #444;
  }

  .page-shell {
    display: block;
  }

  .site-content {
    max-width: none;
    padding: 0;
  }
}