:root {
  color-scheme: light;
  --text: #111827;
  --muted: #4b5563;
  --border: #e5e7eb;
  --surface: #fff;
  --surface-soft: #f8f9fa;
  --link: #527d9a;
  --link-hover: #035;
  --focus: #2563eb;
  --nav-h: 72px;
  --z-progress: 1200;
  --z-fab: 1150;
  --z-skip: 1300;
}

#content :target {
  scroll-margin-top: 0.75rem;
}

body {
  background: var(--surface);
  color: var(--text);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.icon {
  width: 1em;
  height: 1em;
  vertical-align: -0.125em;
  flex: 0 0 auto;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
  width: auto;
  height: auto;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  background: #111827;
  color: #fff;
  z-index: var(--z-skip);
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
  border-radius: 4px;
}

.content a {
  text-underline-offset: 0.16em;
}

.navbar {
  background: var(--surface-soft);
  max-width: 800px;
  margin: 0 auto 2rem;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem 1rem;
  border-bottom: 1px solid #e9ecef;
  box-sizing: border-box;
}

.navbar-brand {
  font-weight: 600;
  color: #333;
  text-decoration: none;
  font-size: 1.4rem;
  cursor: pointer;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  transition: color 0.18s ease;
}

.navbar-brand:hover {
  color: #111827;
  text-decoration: none;
}

.navbar-links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 0.15rem 0.45rem;
}

.navbar-links a {
  margin-left: 0;
  color: #666;
  text-decoration: none;
  font-size: 1.05rem;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 0.5rem;
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.navbar-links a.active {
  color: #111827;
  background: #e5edf5;
  font-weight: 600;
}

body.index-page .title {
  display: none;
}

.navbar-links a:hover {
  color: #333;
}

.reading-time {
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: 0;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem 0.55rem;
  margin: -0.35rem 0 1.35rem;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

.article-meta a {
  color: inherit;
  text-decoration: none;
}

.article-meta a:hover {
  color: #374151;
  text-decoration: none;
}

.article-meta-sep {
  color: #c4c8d0;
  user-select: none;
}

#postamble {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.35rem 1rem;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
  padding: 0 1rem;
  box-sizing: border-box;
  text-align: left;
}

#postamble .postamble-sep {
  color: #9ca3af;
  user-select: none;
}

#postamble .postamble-main {
  flex: 1 1 auto;
  min-width: 0;
  text-align: left;
}

#postamble .creator {
  margin-left: auto;
  text-align: right;
  flex: 0 0 auto;
  max-width: 100%;
  font-size: 0.85rem;
  color: #4b5563;
  float: none;
  display: block;
}

#postamble.is-compact {
  justify-content: flex-end;
}

body.index-page #postamble {
  justify-content: space-between;
  gap: 0.25rem;
  margin-top: 0.75rem;
  color: var(--muted);
  font-size: 0.86rem;
}

body.index-page #postamble .creator {
  margin-left: auto;
  text-align: right;
  font-size: inherit;
}

@media (max-width: 640px) {
  .article-meta {
    margin-top: -0.15rem;
    margin-bottom: 1.1rem;
  }

  #postamble .creator {
    margin-left: 0;
    flex-basis: 100%;
    text-align: left;
  }
}

#table-of-contents {
  background: var(--surface-soft);
  padding: 1rem 0;
  margin-bottom: 2rem;
  border-radius: 4px;
  box-sizing: border-box;
}

#table-of-contents h2 {
  font-size: 1rem;
  margin: 0 0 0.5rem 0;
}

#table-of-contents ul {
  margin: 0;
  padding-left: 1.2rem;
}

#table-of-contents li {
  margin: 0.2rem 0;
}

#table-of-contents a {
  display: inline-block;
  min-height: 32px;
  padding: 0.15rem 0.25rem;
  border-radius: 6px;
  text-decoration: none;
}

#table-of-contents a:hover {
  background: rgba(0, 0, 0, 0.04);
  text-decoration: none;
}

#table-of-contents a:focus-visible {
  background: rgba(37, 99, 235, 0.12);
}

#table-of-contents a.active {
  background: rgba(37, 99, 235, 0.14);
  color: #111827;
  font-weight: 600;
}

#table-of-contents ul ul {
  margin-top: 0.15rem;
}

#table-of-contents ul ul a {
  font-size: 0.95em;
  color: #4b5563;
}

.content {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1rem;
  font-size: 1.02rem;
  line-height: 1.7;
  letter-spacing: 0.01em;
  box-sizing: border-box;
}

.content p {
  margin: 0.85rem 0;
}

.content li {
  line-height: 1.68;
}

.content h1,
.content h2,
.content h3,
.content h4 {
  line-height: 1.38;
  letter-spacing: 0.005em;
}

.content h2 {
  margin-top: 1.5rem;
}

.content h3 {
  margin-top: 1.2rem;
}

.content img {
  max-width: 100%;
  height: auto;
}

.content table {
  border-collapse: collapse;
  width: 100%;
  max-width: 100%;
  margin: 1rem 0;
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.content th,
.content td {
  border: 1px solid #ddd;
  padding: 8px 12px;
  text-align: left;
}

.content th {
  background: #f8f9fa;
}

.content blockquote {
  border-left: 4px solid #ddd;
  margin: 1rem 0;
  padding: 0.5rem 1rem;
  color: #4b5563;
}

.content p,
.content li {
  overflow-wrap: anywhere;
}

.org-src-container {
  margin: 1.1rem 0;
  position: relative;
}

pre.src,
pre.example {
  max-width: 100%;
  box-sizing: border-box;
  overflow: auto;
  line-height: 1.55;
  tab-size: 2;
  -webkit-overflow-scrolling: touch;
}

pre.src {
  border-radius: 8px;
}

.code-copy-btn {
  position: absolute;
  top: 0.45rem;
  right: 0.45rem;
  min-height: 44px;
  min-width: 44px;
  padding: 0.25rem 0.45rem;
  border-radius: 10px;
  border: 1px solid rgba(209, 213, 219, 0.85);
  background: rgba(255, 255, 255, 0.72);
  color: #111827;
  font-size: 0.8rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  opacity: 0.6;
}

.code-copy-btn:hover {
  background: #fff;
  border-color: #9ca3af;
}

.code-copy-btn:active {
  background: #f3f4f6;
}

.code-copy-btn.is-copied {
  border-color: #16a34a;
  color: #166534;
}

.code-copy-btn.is-error {
  border-color: #dc2626;
  color: #991b1b;
}

.code-copy-btn:hover,
.code-copy-btn:focus-visible {
  opacity: 1;
}

.code-copy-btn .label {
  display: none;
}

.code-copy-btn:hover .label,
.code-copy-btn:focus-visible .label {
  display: inline;
}

body.index-page .outline-3 > h3 {
  display: inline-block;
  margin: 1rem 0 0.35rem;
}

body.index-page details.archive-year {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.6rem 0.75rem;
  background: var(--surface);
  margin: 0.55rem 0;
}

body.index-page details.archive-year > summary {
  cursor: pointer;
  list-style: none;
  user-select: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  font-weight: 600;
  color: #111827;
}

body.index-page details.archive-year > summary::-webkit-details-marker {
  display: none;
}

body.index-page details.archive-year > summary:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 4px;
  border-radius: 6px;
}

body.index-page details.archive-year > summary:hover {
  color: #0f172a;
}

body.index-page details.archive-year > summary .meta {
  font-weight: 500;
  color: #6b7280;
  font-size: 0.95em;
}

body.index-page details.archive-year > summary .meta::after {
  content: "";
  display: inline-block;
  width: 0.45rem;
  height: 0.45rem;
  margin-left: 0.5rem;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg) translateY(-0.15rem);
  transition: transform 0.18s ease;
}

body.index-page details.archive-year[open] > summary .meta::after {
  transform: rotate(225deg) translateY(0.1rem);
}

body.index-page details.archive-year[open] {
  background: #fbfdff;
}

body.index-page details.archive-year .outline-text-3 {
  margin-top: 0.45rem;
}

body.index-page .archive-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0.5rem 0 1rem;
}

body.index-page .archive-toolbar button {
  min-height: 44px;
  padding: 0.35rem 0.6rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

body.index-page .archive-toolbar button:hover {
  background: #f9fafb;
}

body.index-page .archive-toolbar button:active {
  background: #f3f4f6;
}

.fab-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: var(--z-fab);
  min-width: 44px;
  min-height: 44px;
  padding: 0 0.6rem;
  border-radius: 999px;
  border: 1px solid #e5e7eb;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  color: #111827;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(6px);
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.fab-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, #60a5fa, #2563eb);
  z-index: var(--z-progress);
  transition: width 0.08s linear;
}

@media (max-width: 900px) {
  .navbar {
    padding: 0.7rem 1rem;
    flex-wrap: wrap;
  }

  #table-of-contents {
    padding: 0.8rem 0;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 16px;
  }

  .navbar {
    align-items: center;
    gap: 0.25rem;
    margin-bottom: 1.1rem;
    padding: 0.75rem 0.875rem 0.65rem;
  }

  .navbar-brand {
    width: 100%;
    justify-content: center;
    min-height: 36px;
    font-size: 1.22rem;
  }

  .navbar-links {
    width: 100%;
    margin: 0;
    padding: 0.15rem 0 0.25rem;
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0.25rem;
    overflow: visible;
  }

  .navbar-links a {
    justify-content: center;
    min-width: 0;
    min-height: 40px;
    padding: 0 0.25rem;
    border: 1px solid var(--border);
    border-radius: 999px;
    background: var(--surface);
    font-size: 0.82rem;
    line-height: 1;
    white-space: nowrap;
  }

  .navbar-links a.active {
    border-color: #c8d8e8;
    background: #eaf2fa;
  }

  .content,
  #postamble {
    padding-left: 0.875rem;
    padding-right: 0.875rem;
  }

  .content {
    font-size: 1rem;
    line-height: 1.72;
  }

  .content table {
    font-size: 0.92rem;
  }

  pre.src,
  pre.example {
    font-size: 0.88rem;
  }

  body.index-page details.archive-year {
    padding: 0.7rem 0.75rem;
  }

  body.index-page details.archive-year > summary {
    gap: 0.5rem;
  }

  body.index-page details.archive-year > summary .meta {
    white-space: nowrap;
  }

  body.index-page .archive-toolbar button {
    flex: 1 1 9rem;
  }
}