:root {
  --paper: #fcfcfa;
  --ink: #282828;
  --muted: #746f6b;
  --faint: #a09b96;
  --rule: #ddd9d3;
  --accent: #3156c8;
  --accent-hover: #1f3e9a;
  --note: #f4f3ef;
  --code: #f3f5f7;
  --selection: #dfe6ff;
  --serif: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #1a1a1a;
    --ink: #e8e6e3;
    --muted: #9e9a96;
    --faint: #6b6763;
    --rule: #333130;
    --accent: #6b8cff;
    --accent-hover: #8fa8ff;
    --note: #242220;
    --code: #1f1f1f;
    --selection: #2a3a5e;
  }
}

:root[data-theme="dark"] {
  --paper: #1a1a1a;
  --ink: #e8e6e3;
  --muted: #9e9a96;
  --faint: #6b6763;
  --rule: #333130;
  --accent: #6b8cff;
  --accent-hover: #8fa8ff;
  --note: #242220;
  --code: #1f1f1f;
  --selection: #2a3a5e;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 3rem;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.64;
  text-rendering: optimizeLegibility;
}

::selection {
  color: var(--ink);
  background: var(--selection);
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.14em;
}

a:hover {
  color: var(--accent-hover);
}

button,
summary {
  font: inherit;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex="0"]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 100;
  padding: 0.45rem 0.7rem;
  transform: translateY(-180%);
  border: 1px solid var(--ink);
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 0.78rem;
}

.skip-link:focus {
  transform: translateY(0);
}

.read-progress {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 80;
  height: 2px;
}

.read-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--accent);
}

.article-header {
  width: min(760px, calc(100% - 3rem));
  margin: 0 auto;
  padding: 5rem 0 4rem;
  text-align: center;
}

.article-header h1 {
  margin: 0;
  font-size: clamp(2.5rem, 5vw, 3.45rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.12;
}

.article-meta {
  margin-bottom: 1.4rem;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
}

.meta-sep {
  margin: 0 0.4rem;
}

.article-shell {
  display: grid;
  grid-template-columns: 210px minmax(0, 660px);
  gap: 50px;
  justify-content: center;
  width: min(1000px, calc(100% - 3rem));
  margin: 0 auto;
  padding-bottom: 8rem;
}

.contents {
  position: sticky;
  top: 2rem;
  align-self: start;
  max-height: calc(100vh - 4rem);
  overflow-y: auto;
  padding-top: 0.3rem;
  padding-right: 0.5rem;
  font-family: var(--sans);
  scrollbar-width: thin;
}

.contents > p {
  margin: 0 0 0.7rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.contents nav {
  display: grid;
  border-top: 1px solid var(--rule);
}

.contents a {
  padding: 0.45rem 0;
  border-bottom: 1px solid #ece9e5;
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.35;
  text-decoration: none;
}

.contents a:hover,
.contents a.is-current {
  color: var(--accent);
}

.contents a.is-current {
  font-weight: 500;
}

.mobile-contents {
  display: none;
}

article {
  width: 100%;
  min-width: 0;
}

.article-section,
.sources {
  scroll-margin-top: 3rem;
}

.article-section + .article-section,
.sources {
  margin-top: 4.5rem;
}

article p {
  margin: 0 0 1.4rem;
}

.introduction > p:first-child {
  font-size: 1.08em;
}

.source-figure {
  margin: 2rem 0 2.6rem;
}

.source-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--rule);
  background: #fff;
}

.source-figure figcaption {
  margin-top: 0.7rem;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.78rem;
  line-height: 1.55;
}

.source-figure--compact {
  margin-top: 1.8rem;
}

.source-figure--tall img {
  max-height: 46rem;
  object-fit: contain;
}

article h2,
.sources h2 {
  margin: 0 0 1.25rem;
  font-size: 1.72rem;
  font-weight: 600;
  letter-spacing: -0.012em;
  line-height: 1.3;
}

article h2:not(:first-child) {
  margin-top: 3.4rem;
}

article h2 > a,
.sources h2 > a {
  margin-left: 0.25rem;
  color: var(--faint);
  font-family: var(--sans);
  font-size: 0.65em;
  font-weight: 400;
  text-decoration: none;
  opacity: 0;
}

article h2:hover > a,
article h2 > a:focus,
.sources h2:hover > a,
.sources h2 > a:focus {
  opacity: 1;
}

article h3 {
  margin: 2.6rem 0 0.75rem;
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.35;
}

article ul,
article ol {
  margin: 0 0 1.5rem;
  padding-left: 1.45rem;
}

article li {
  margin-bottom: 0.6rem;
  padding-left: 0.25rem;
}

article sup a {
  color: var(--accent);
  font-family: var(--sans);
  font-size: 0.72em;
  font-weight: 500;
  text-decoration: none;
}

article sup + sup {
  margin-left: 0.14em;
}

code {
  padding: 0.08em 0.28em;
  border: 1px solid #dedfe1;
  border-radius: 3px;
  background: var(--code);
  font-family: var(--mono);
  font-size: 0.78em;
}

pre code {
  padding: 0;
  border: 0;
  background: none;
  font-size: inherit;
}

.thesis {
  margin: 2.4rem 0 2.8rem;
  padding: 0.2rem 0 0.2rem 1.2rem;
  border-left: 3px solid var(--accent);
  font-size: 1.28rem;
  font-style: italic;
  line-height: 1.5;
}

.article-note {
  margin: 2rem 0;
  padding: 1rem 1.15rem;
  border-left: 2px solid var(--rule);
  background: var(--note);
  font-size: 0.9rem;
  line-height: 1.6;
}

.reference-appendix {
  margin: 2rem 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.reference-appendix summary {
  padding: 0.9rem 0;
  color: var(--muted);
  cursor: pointer;
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 500;
}

.reference-appendix[open] {
  padding-bottom: 1rem;
}

.reference-appendix[open] summary {
  margin-bottom: 1.5rem;
}

table {
  display: block;
  width: 100%;
  max-width: 100%;
  margin: 2rem 0;
  overflow-x: auto;
  border-collapse: collapse;
  font-family: var(--sans);
  font-size: 0.81rem;
  line-height: 1.45;
  text-align: left;
}

thead,
tbody {
  min-width: 610px;
}

th,
td {
  min-width: 150px;
  padding: 0.65rem 0.8rem 0.65rem 0;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}

th {
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

th:first-child,
td:first-child {
  min-width: 180px;
}

.code-block,
article pre {
  margin: 2rem 0;
}

.code-block {
  border: 1px solid var(--rule);
  background: var(--code);
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.75rem;
  border-bottom: 1px solid var(--rule);
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.68rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.copy-button {
  padding: 0.25rem 0.5rem;
  border: 1px solid #c8c8c8;
  border-radius: 2px;
  color: var(--muted);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 0.68rem;
  cursor: pointer;
}

.copy-button:hover {
  color: var(--ink);
  border-color: var(--ink);
}

pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 1rem 1.1rem;
  border: 1px solid var(--rule);
  border-radius: 0;
  background: var(--code);
  font-family: var(--mono);
  font-size: 0.77rem;
  line-height: 1.7;
}

.code-block pre {
  margin: 0;
  border: 0;
}

.kw {
  color: #8b3a57;
}

.str {
  color: #1c6b55;
}

.num {
  color: #3156c8;
}

.key {
  color: #604a9b;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .kw { color: #d98da6; }
  :root:not([data-theme="light"]) .str { color: #6bc4a8; }
  :root:not([data-theme="light"]) .num { color: #6b8cff; }
  :root:not([data-theme="light"]) .key { color: #b199d6; }
  :root:not([data-theme="light"]) code { border-color: #3a3a3a; }
  :root:not([data-theme="light"]) .copy-button { border-color: #555; background: var(--code); }
  :root:not([data-theme="light"]) .copy-button:hover { color: var(--ink); border-color: var(--ink); }
}

:root[data-theme="dark"] .kw { color: #d98da6; }
:root[data-theme="dark"] .str { color: #6bc4a8; }
:root[data-theme="dark"] .num { color: #6b8cff; }
:root[data-theme="dark"] .key { color: #b199d6; }
:root[data-theme="dark"] code { border-color: #3a3a3a; }
:root[data-theme="dark"] .copy-button { border-color: #555; background: var(--code); }
:root[data-theme="dark"] .copy-button:hover { color: var(--ink); border-color: var(--ink); }

.caption {
  margin-top: -1.4rem;
  color: var(--muted);
  font-size: 0.8rem;
  font-style: italic;
}

.rules-list li {
  margin-bottom: 0.9rem;
  line-height: 1.55;
}

.key-number {
  border-left-color: var(--accent);
  background: var(--note);
}

.closing {
  padding-top: 0.2rem;
  border-top: 1px solid var(--rule);
}

.sources {
  padding-top: 3rem;
  border-top: 1px solid var(--rule);
}

.sources ol {
  padding-left: 1.3rem;
}

.sources h3 {
  margin-top: 2.2rem;
  margin-bottom: 0.8rem;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.sources li {
  margin-bottom: 0.8rem;
  font-size: 0.86rem;
  line-height: 1.55;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2rem max(1.5rem, calc((100vw - 1180px) / 2));
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.78rem;
}

.site-footer a {
  color: var(--muted);
  text-decoration: none;
}

.footer-discuss {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.discuss-link {
  padding: 0.3rem 0.6rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  font-size: 0.72rem;
}

.discuss-link:hover {
  color: var(--accent);
  border-color: var(--accent);
}

@media (max-width: 900px) {
  .article-shell {
    display: block;
    width: min(660px, calc(100% - 3rem));
  }

  .contents {
    display: none;
  }

  .mobile-contents {
    display: block;
    margin-bottom: 3rem;
    border-top: 1px solid var(--rule);
    border-bottom: 1px solid var(--rule);
    font-family: var(--sans);
    font-size: 0.78rem;
  }

  .mobile-contents summary {
    padding: 0.75rem 0;
    color: var(--muted);
    cursor: pointer;
  }

  .mobile-contents nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.35rem 1rem;
    padding: 0 0 0.9rem;
  }

  .mobile-contents a {
    color: var(--muted);
    text-decoration: none;
  }
}

@media (max-width: 620px) {
  body {
    font-size: 17px;
  }

  .article-header {
    width: calc(100% - 2rem);
    padding: 3.5rem 0 3rem;
  }

  .article-header h1 {
    font-size: 2.35rem;
  }

  .article-shell {
    width: calc(100% - 2rem);
    padding-bottom: 5rem;
  }

  .mobile-contents nav {
    grid-template-columns: 1fr;
  }

  .article-section + .article-section,
  .sources {
    margin-top: 3.8rem;
  }

  article h2,
  .sources h2 {
    font-size: 1.55rem;
  }

  article h2 > a,
  .sources h2 > a {
    display: none;
  }

  .thesis {
    font-size: 1.15rem;
  }

  pre {
    margin-right: -0.15rem;
    margin-left: -0.15rem;
    padding: 0.85rem;
    font-size: 0.68rem;
  }

  .site-footer {
    flex-direction: column-reverse;
    gap: 1rem;
    padding: 1.5rem 1rem;
  }

}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}