:root {
  --bg: #f4f0e6;
  --text: #333333;
  --text-secondary: #888888;
  --link: #1a0dab;
  --link-visited: #4b0082;
  --border: #e4dfd4;
  --list-divider: #d8cfbd;
  --card-bg: #ede8dd;
  --code-bg: #e9e4d8;
  --blockquote-border: #ddd;
  --fn-highlight: rgba(255, 200, 50, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1c1c;
    --text: #dddddd;
    --text-secondary: #888888;
    --link: #8ab4f8;
    --link-visited: #b18ad8;
    --border: #333333;
    --list-divider: #454545;
    --card-bg: #252525;
    --code-bg: #2a2a2a;
    --blockquote-border: #444;
    --fn-highlight: rgba(255, 200, 50, 0.07);
  }
}

html.light {
  --bg: #f4f0e6;
  --text: #333333;
  --text-secondary: #888888;
  --link: #1a0dab;
  --link-visited: #4b0082;
  --border: #e4dfd4;
  --list-divider: #d8cfbd;
  --card-bg: #ede8dd;
  --code-bg: #e9e4d8;
  --blockquote-border: #ddd;
  --fn-highlight: rgba(255, 200, 50, 0.12);
}

html.dark {
  --bg: #1c1c1c;
  --text: #dddddd;
  --text-secondary: #888888;
  --link: #8ab4f8;
  --link-visited: #b18ad8;
  --border: #333333;
  --list-divider: #454545;
  --card-bg: #252525;
  --code-bg: #2a2a2a;
  --blockquote-border: #444;
  --fn-highlight: rgba(255, 200, 50, 0.07);
}

/* iA Writer Quattro (OFL-1.1, by Information Architects Inc.) */
@font-face {
  font-family: 'iA Writer Quattro';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('/css/fonts/ia-writer-quattro-latin-400-normal.woff2') format('woff2');
}
@font-face {
  font-family: 'iA Writer Quattro';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('/css/fonts/ia-writer-quattro-latin-700-normal.woff2') format('woff2');
}
@font-face {
  font-family: 'iA Writer Quattro';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url('/css/fonts/ia-writer-quattro-latin-400-italic.woff2') format('woff2');
}
@font-face {
  font-family: 'iA Writer Quattro';
  font-style: italic;
  font-weight: 700;
  font-display: swap;
  src: url('/css/fonts/ia-writer-quattro-latin-700-italic.woff2') format('woff2');
}

* {
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  max-width: 720px;
  margin: 0 auto;
  padding: 20px;
  line-height: 1.6;
  font-size: 18px;
  transition: background-color 0.2s, color 0.2s;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

a:visited {
  color: var(--link-visited);
}

h1, h2, h3 {
  line-height: 1.3;
}

h1 {
  font-size: 1.6em;
  margin-bottom: 7px;
}

/* Top bar */
#top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
#rss-link {
  width: 16px;
  height: 20px;
  display: flex;
  align-items: center;
  color: var(--text-secondary);
}
#rss-link svg {
  width: 16px;
  height: 16px;
  display: block;
  flex-shrink: 0;
}
#color-mode-switch {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
}

#color-mode-switch svg {
  width: 20px;
  height: 20px;
  stroke: var(--text-secondary);
}

#color-mode-switch input[type="checkbox"] {
  display: none;
}

#color-mode-switch label {
  cursor: pointer;
  font-size: 0;
  width: 40px;
  height: 20px;
  background: var(--border);
  border-radius: 10px;
  position: relative;
  transition: background 0.2s;
}

#color-mode-switch label::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  background: var(--text);
  border-radius: 50%;
  transition: transform 0.2s;
}

#color-mode-switch input:checked + label::after {
  transform: translateX(20px);
}

/* Post list */
ul.post-list {
  list-style: none;
  padding: 0;
}

ul.post-list li {
  margin-bottom: 8px;
  padding: 8px 0;
  border-bottom: 1px solid var(--list-divider);
}

.post-meta {
  color: var(--text-secondary);
  font-size: 0.85em;
  display: block;
}

.post-list h3 {
  margin: 4px 0 12px 0;
  font-size: 0.92em;
  font-weight: 500;
  font-family: 'iA Writer Quattro', Georgia, 'Times New Roman', Times, serif;
}

.post-list a {
  color: var(--text);
}

.post-list a:hover {
  color: var(--link);
  text-decoration: underline;
}

/* Short-post preview dropdown */
.post-toc-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  column-gap: 10px;
  row-gap: 10px;
  margin-top: -4px;
}
.post-word-count {
  font-size: 0.85em;
  font-family: 'Courier New', monospace;
  color: var(--text-secondary);
  white-space: nowrap;
}
.post-preview {
  display: contents;
}
.post-preview summary {
  flex: 0 0 auto;
  cursor: pointer;
  user-select: none;
  font-size: 0.85em;
  font-family: 'Courier New', monospace;
  color: var(--text-secondary);
  list-style: none;
  white-space: nowrap;
}
.post-preview summary::-webkit-details-marker {
  display: none;
}
.post-preview summary::before {
  content: '▸ ';
  color: var(--text-secondary);
}
.post-preview[open] summary::before {
  content: '▾ ';
}
.post-preview summary:hover {
  color: var(--link);
}
.post-preview-body {
  flex: 1 1 100%;
  font-size: 0.9em;
  line-height: 1.6;
  color: var(--text);
  padding: 8px 12px;
  border-left: 2px solid var(--border);
  background: var(--card-bg);
  border-radius: 4px;
}
.post-preview-body p {
  margin: 0 0 0.6em;
  text-align: left;
}
.post-preview-body p:last-child,
.post-preview-body p:last-of-type {
  margin-bottom: 0;
}

/* Category header */
.categories-header {
  text-align: center;
  margin: 10px 0;
}

.categories-header hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 15px 0;
}

.toc-category {
  display: inline-block;
  margin: 0 6px;
}

.toc-category a {
  color: var(--text-secondary);
  font-size: 0.9em;
}

.toc-category a:hover {
  color: var(--link);
}

.toc-category-pinned a {
  font-weight: 600;
}

/* Post content (pandoc output) */
.markdown-body {
  font-family: Georgia, 'Times New Roman', Times, serif;
  line-height: 1.8;
}

.markdown-body p {
  margin: 1em 0;
  text-align: justify;
}

.markdown-body code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.9em;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
}

.markdown-body pre {
  background: var(--code-bg);
  padding: 16px;
  border-radius: 4px;
  overflow-x: auto;
}

.markdown-body pre code {
  padding: 0;
  background: none;
}

.markdown-body blockquote {
  margin: 1em 0;
  padding-left: 15px;
  border-left: 3px solid var(--blockquote-border);
  color: var(--text-secondary);
}

.markdown-body img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  display: block;
  margin: 0 auto;
}

.markdown-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 1em 0;
}

.markdown-body table th,
.markdown-body table td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: left;
}

.markdown-body table tr:nth-child(2n) {
  background: var(--card-bg);
}

/* Small text utility */
small {
  color: var(--text-secondary);
}

/* Footnote margin notes */
.sidenote-content {
  display: none;
  font-size: 0.85em;
  line-height: 1.4;
  color: var(--text-secondary);
  transition: background-color 0.2s;
  border-radius: 4px;
}
.sidenote-content p {
  margin: 0;
}
.sidenote-wrapper .footnote-ref {
  display: inline-block;
  padding: 0 2px;
  border-radius: 3px;
  transition: background-color 0.2s;
}
@media (min-width: 1024px) {
  .sidenote-wrapper:hover .footnote-ref {
    background: var(--fn-highlight);
  }
  .sidenote-wrapper:hover .sidenote-content {
    background: var(--fn-highlight);
  }
}
.sidenote-number {
  font-weight: 600;
}
.footnotes {
  font-size: 0.85em;
  color: var(--text-secondary);
}
.footnotes ol {
  padding-left: 1.2em;
  padding-right: 1.2em;
}
.footnotes hr {
  border: none;
  border-top: 1px solid var(--border);
}

@media (min-width: 1024px) {
  body {
    max-width: 960px;
  }
  .markdown-body {
    position: relative;
    max-width: 620px;
    margin: 0 auto;
  }
  .sidenote-content {
    display: grid;
    grid-template-columns: 1.5em 1fr;
    gap: 0.3em;
    position: absolute;
    left: calc(100% + 12px);
    width: 270px;
    text-align: left;
  }
  .sidenote-content p {
    margin: 0 0 0.4em;
  }
  .sidenote-number {
    text-align: right;
  }
  .sidenote-text {
    border-left: 1px solid var(--border);
    padding-left: 12px;
  }
}

@media (max-width: 1023px) {
  .sidenote-content {
    grid-template-columns: 1.5em 1fr;
    gap: 0.3em;
    position: fixed;
    z-index: 100;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 10px 12px;
    max-width: 300px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  }
  .sidenote-content p {
    margin: 0 0 0.4em;
  }
  .sidenote-number {
    text-align: right;
  }
  .sidenote-text {
    border-left: 1px solid var(--border);
    padding-left: 12px;
  }
  .sidenote-wrapper.active .sidenote-content {
    display: grid;
  }
}

/* Responsive */
@media (max-width: 600px) {
  body {
    padding: 12px;
    font-size: 17px;
  }
}

@media (max-width: 400px) {
  body {
    padding: 8px;
  }
}

/* PlantUML copy button */
.plantuml-container {
  position: relative;
  width: fit-content;
  margin: 0 auto;
}
.plantuml-buttons {
  position: absolute;
  top: 8px;
  right: 8px;
  display: none;
  gap: 4px;
}
.plantuml-container:hover .plantuml-buttons {
  display: flex;
}
.plantuml-copy-btn {
  width: 32px;
  height: 32px;
  padding: 6px;
  border: none;
  border-radius: 6px;
  background: rgba(0,0,0,0.5);
  color: #fff;
  cursor: pointer;
}
.plantuml-copy-btn:hover {
  background: rgba(0,0,0,0.7);
}
.plantuml-copy-btn svg {
  width: 100%;
  height: 100%;
  display: block;
}

/* Code block copy button */
.code-block-wrapper {
  position: relative;
}
.code-copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 32px;
  height: 32px;
  padding: 6px;
  border: none;
  border-radius: 6px;
  background: rgba(0,0,0,0.5);
  color: #fff;
  cursor: pointer;
  display: none;
}
.code-block-wrapper:hover .code-copy-btn {
  display: block;
}
.code-copy-btn:hover {
  background: rgba(0,0,0,0.7);
}
.code-copy-btn svg {
  width: 100%;
  height: 100%;
  display: block;
}

/* Math LaTeX copy button */
.math-wrapper.math-display-wrapper {
  display: block;
  position: relative;
}
.math-copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 32px;
  height: 32px;
  padding: 6px;
  border: none;
  border-radius: 6px;
  background: rgba(0,0,0,0.5);
  color: #fff;
  cursor: pointer;
  display: none;
}
.math-wrapper:hover .math-copy-btn {
  display: block;
}
.math-copy-btn:hover {
  background: rgba(0,0,0,0.7);
}
.math-copy-btn svg {
  width: 100%;
  height: 100%;
  display: block;
}