:root {
  color-scheme: light;
  --paper: #f4f1ea;
  --paper-raised: #fbf9f4;
  --ink: #22201e;
  --muted: #6d6862;
  --faint: #969089;
  --line: #d7d1c8;
  --line-strong: #aaa39a;
  --accent: #c9482b;
  --accent-deep: #9c2f1b;
  --code: #e9e4dc;
  --selection: #f2c9ba;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", system-ui, sans-serif;
  --font-mono: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
  --rail: 260px;
  --topbar: 64px;
  --content: 780px;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --paper: #1d1c1a;
  --paper-raised: #252320;
  --ink: #ebe6dc;
  --muted: #b1aaa0;
  --faint: #7f7971;
  --line: #403c37;
  --line-strong: #625c54;
  --accent: #ed714f;
  --accent-deep: #f08b6e;
  --code: #2d2a26;
  --selection: #713827;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topbar) + 24px);
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.78;
  text-rendering: optimizeLegibility;
}

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

a {
  color: inherit;
  text-decoration-color: color-mix(in srgb, var(--accent) 65%, transparent);
  text-underline-offset: 0.2em;
  text-decoration-thickness: 1px;
}

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

button,
input {
  font: inherit;
}

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 80%, transparent);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 8px;
  left: 8px;
  padding: 8px 12px;
  color: var(--paper);
  background: var(--ink);
  transform: translateY(-150%);
}

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

.topbar {
  position: sticky;
  z-index: 30;
  top: 0;
  display: flex;
  min-height: var(--topbar);
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  backdrop-filter: blur(12px);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
}

.mark {
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  color: var(--paper-raised);
  background: var(--accent-deep);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: -0.05em;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 18px;
}

.cutoff {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.plain-button {
  padding: 4px 0;
  color: var(--ink);
  border: 0;
  border-bottom: 1px solid var(--line-strong);
  background: transparent;
  cursor: pointer;
}

.plain-button:hover {
  color: var(--accent-deep);
  border-color: var(--accent);
}

.site-shell {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr);
  min-height: calc(100vh - var(--topbar));
}

.site-rail {
  position: sticky;
  top: var(--topbar);
  align-self: start;
  height: calc(100vh - var(--topbar));
  padding: 32px 24px;
  overflow-y: auto;
  border-right: 1px solid var(--line);
}

.rail-kicker,
.toc-label {
  margin: 0 0 18px;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.rail-link {
  display: flex;
  min-height: 42px;
  align-items: baseline;
  gap: 12px;
  padding: 8px 0;
  color: var(--muted);
  border-bottom: 1px solid transparent;
  font-size: 0.88rem;
  line-height: 1.35;
  text-decoration: none;
}

.rail-link:hover {
  color: var(--ink);
  border-bottom-color: var(--line);
}

.rail-link.is-active {
  color: var(--ink);
  font-weight: 700;
}

.rail-link.is-active::before {
  width: 3px;
  height: 1.05em;
  margin-left: -12px;
  background: var(--accent);
  content: "";
}

.rail-number {
  min-width: 22px;
  color: var(--faint);
  font-family: var(--font-mono);
  font-size: 0.7rem;
}

.rail-foot {
  margin-top: 48px;
  color: var(--faint);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  line-height: 1.6;
}

.page-main {
  display: grid;
  grid-template-columns: minmax(0, var(--content)) minmax(160px, 220px);
  gap: clamp(48px, 7vw, 104px);
  justify-content: center;
  padding: 72px clamp(32px, 5vw, 88px) 48px;
}

.prose {
  min-width: 0;
}

.prose > h1:first-child {
  max-width: 13ch;
  margin: 0 0 26px;
  font-size: clamp(2.65rem, 5.6vw, 5.7rem);
  font-weight: 780;
  letter-spacing: -0.055em;
  line-height: 0.98;
}

body[data-page="home"] .prose > h1:first-child {
  max-width: 9ch;
  font-size: clamp(3.2rem, 7vw, 6.8rem);
}

.prose > h1:first-child::before {
  display: block;
  width: 68px;
  height: 6px;
  margin-bottom: 28px;
  background: var(--accent);
  content: "";
}

.prose h2 {
  margin: 4.8rem 0 1.2rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line-strong);
  font-size: clamp(1.7rem, 2.6vw, 2.45rem);
  letter-spacing: -0.035em;
  line-height: 1.2;
}

.prose h3 {
  margin: 2.8rem 0 0.8rem;
  padding-left: 14px;
  border-left: 3px solid var(--accent);
  font-size: 1.15rem;
  line-height: 1.45;
}

.prose h4 {
  margin: 2rem 0 0.6rem;
  font-size: 1rem;
}

.prose p,
.prose li {
  color: color-mix(in srgb, var(--ink) 93%, var(--muted));
}

.prose p {
  margin: 0.85em 0;
}

.prose ul,
.prose ol {
  padding-left: 1.35em;
}

.prose li {
  margin: 0.5em 0;
  padding-left: 0.25em;
}

.prose li::marker {
  color: var(--accent);
}

.prose blockquote {
  margin: 1.4rem 0 2.8rem;
  padding: 1rem 0 1rem 20px;
  color: var(--muted);
  border-left: 1px solid var(--accent);
  font-size: 1.08rem;
}

.prose blockquote p {
  margin: 0;
  color: inherit;
}

.prose strong {
  color: var(--ink);
  font-weight: 720;
}

.prose code {
  padding: 0.08em 0.3em;
  color: var(--ink);
  background: var(--code);
  font-family: var(--font-mono);
  font-size: 0.86em;
}

.prose pre {
  margin: 1.5rem 0;
  padding: 20px;
  overflow: auto;
  border: 1px solid var(--line);
  background: var(--code);
  line-height: 1.6;
}

.prose pre code {
  padding: 0;
  background: transparent;
}

.table-wrap {
  max-width: 100%;
  margin: 1.5rem 0 2rem;
  overflow-x: auto;
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--line-strong);
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  line-height: 1.55;
}

.prose th,
.prose td {
  min-width: 7.5rem;
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

.prose th {
  color: var(--muted);
  background: color-mix(in srgb, var(--paper-raised) 65%, transparent);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}

.evidence-image,
.evidence-video {
  display: block;
  width: 100%;
  height: auto;
  margin: 2rem 0;
  border: 1px solid var(--line-strong);
  background: var(--code);
}

.evidence-image {
  max-height: 680px;
  object-fit: contain;
}

.evidence-video {
  max-height: 620px;
}

.external-link::after {
  margin-left: 0.18em;
  color: var(--faint);
  content: "↗";
  font-size: 0.72em;
}

.page-toc {
  position: sticky;
  top: calc(var(--topbar) + 32px);
  align-self: start;
  max-height: calc(100vh - var(--topbar) - 64px);
  overflow-y: auto;
}

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

.page-toc li {
  margin: 0 0 10px;
  line-height: 1.35;
}

.page-toc a {
  color: var(--muted);
  font-size: 0.77rem;
  text-decoration: none;
}

.page-toc a:hover {
  color: var(--accent-deep);
}

.page-toc .toc-sub {
  padding-left: 14px;
}

.page-footer {
  grid-column: 1 / -1;
  display: flex;
  justify-content: space-between;
  gap: 24px;
  margin-top: 72px;
  padding-top: 24px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 0.8rem;
}

.page-footer p {
  margin: 0;
}

.search-dialog {
  width: min(720px, calc(100vw - 32px));
  max-height: min(720px, calc(100vh - 48px));
  padding: 0;
  color: var(--ink);
  border: 1px solid var(--line-strong);
  border-radius: 0;
  background: var(--paper-raised);
  box-shadow: 0 20px 70px rgb(0 0 0 / 0.24);
}

.search-dialog::backdrop {
  background: rgb(18 17 15 / 0.66);
  backdrop-filter: blur(3px);
}

.search-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
}

.search-head label {
  font-weight: 700;
}

.search-head button {
  color: var(--muted);
  border: 0;
  background: transparent;
  cursor: pointer;
}

.search-input {
  width: calc(100% - 44px);
  margin: 22px 22px 8px;
  padding: 14px 0;
  color: var(--ink);
  border: 0;
  border-bottom: 2px solid var(--ink);
  border-radius: 0;
  background: transparent;
  font-size: 1.3rem;
}

.search-hint {
  margin: 0 22px 16px;
  color: var(--muted);
  font-size: 0.75rem;
}

.search-results {
  padding: 0 22px 24px;
  overflow-y: auto;
}

.search-result {
  display: block;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  text-decoration: none;
}

.search-result strong {
  display: block;
  margin-bottom: 3px;
}

.search-result span {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.7rem;
}

.search-empty {
  padding: 28px 0;
  color: var(--muted);
}

.noscript {
  position: fixed;
  z-index: 50;
  right: 16px;
  bottom: 16px;
  max-width: 420px;
  padding: 12px 16px;
  color: var(--paper-raised);
  background: var(--ink);
  font-size: 0.8rem;
}

@media (max-width: 1120px) {
  :root {
    --rail: 220px;
  }

  .page-main {
    grid-template-columns: minmax(0, var(--content));
  }

  .page-toc {
    display: none;
  }
}

@media (max-width: 760px) {
  :root {
    --topbar: 58px;
  }

  .topbar {
    padding: 0 16px;
  }

  .wordmark span:last-child,
  .cutoff {
    display: none;
  }

  .top-actions {
    gap: 14px;
  }

  .site-shell {
    display: block;
  }

  .site-rail {
    position: static;
    display: flex;
    width: 100%;
    height: auto;
    gap: 18px;
    padding: 13px 16px;
    overflow-x: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    scrollbar-width: thin;
  }

  .rail-kicker,
  .rail-foot,
  .rail-number {
    display: none;
  }

  .rail-link {
    flex: 0 0 auto;
    min-height: 32px;
    padding: 5px 0;
    white-space: nowrap;
  }

  .rail-link.is-active::before {
    display: none;
  }

  .rail-link.is-active {
    color: var(--accent-deep);
    border-bottom-color: var(--accent);
  }

  .page-main {
    display: block;
    padding: 44px 20px 32px;
  }

  .prose > h1:first-child,
  body[data-page="home"] .prose > h1:first-child {
    max-width: 11ch;
    font-size: clamp(2.5rem, 15vw, 4.2rem);
  }

  .prose h2 {
    margin-top: 3.8rem;
  }

  .prose th,
  .prose td {
    min-width: 8.5rem;
    padding: 10px 12px;
  }

  .page-footer {
    display: block;
  }

  .page-footer p + p {
    margin-top: 8px;
  }
}

@media (max-width: 420px) {
  body {
    font-size: 15px;
  }

  .plain-button {
    font-size: 0.85rem;
  }

  .page-main {
    padding-inline: 16px;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media print {
  .topbar,
  .site-rail,
  .page-toc,
  .search-dialog,
  .noscript {
    display: none !important;
  }

  .site-shell,
  .page-main {
    display: block;
  }

  .page-main {
    padding: 0;
  }

  body {
    color: #111;
    background: #fff;
  }
}