/* ==========================================================================
   sllt — Minimalist Developer Blog Design System
   Inspired by paco.me, rauno.me, Distill.pub & Linear
   Zero information bloat · High-craft typography, Markdown, KaTeX & Code
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;450;500;600;700&family=JetBrains+Mono:ital,wght@0,400;0,500;0,600;1,400&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;1,6..72,400&display=swap');

:root {
  /* Light Mode — Warm Gallery Paper & Carbon Ink */
  --bg: #faf9f5;
  --bg-surface: #ffffff;
  --bg-subtle: #f2f0e8;
  --bg-hover: rgba(20, 20, 19, 0.04);
  --bg-code: #f5f4ef;
  --bg-code-bar: #edece5;

  --text: #161615;
  --text-secondary: #4e4d49;
  --text-muted: #82817a;
  --text-faint: #b3b2aa;

  --border: #e4e2d9;
  --border-subtle: #eceae2;
  --border-strong: #cbc8bc;

  --accent: #2563eb;
  --accent-soft: rgba(37, 99, 235, 0.08);
  --emerald: #059669;
  --emerald-soft: rgba(5, 150, 105, 0.1);
  --amber: #d97706;
  --amber-soft: rgba(217, 119, 6, 0.1);
  --rose: #e11d48;
  --rose-soft: rgba(225, 29, 72, 0.1);

  /* Syntax Highlighting (Refined Light) */
  --syn-kw: #c92a2a;
  --syn-fn: #5f3dc4;
  --syn-str: #0b7285;
  --syn-num: #1864ab;
  --syn-cmt: #868e96;
  --syn-typ: #b45309;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  --font-serif: 'Newsreader', Georgia, "Songti SC", "Noto Serif CJK SC", serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Menlo, Monaco, Consolas, monospace;

  --max-w: 690px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.035), 0 4px 12px rgba(0, 0, 0, 0.02);
}

[data-theme="dark"] {
  /* Dark Mode — Deep Matte Obsidian */
  --bg: #0c0c0e;
  --bg-surface: #131316;
  --bg-subtle: #19191d;
  --bg-hover: rgba(255, 255, 255, 0.045);
  --bg-code: #111114;
  --bg-code-bar: #17171b;

  --text: #ededec;
  --text-secondary: #a6a6a1;
  --text-muted: #70706b;
  --text-faint: #464642;

  --border: #232328;
  --border-subtle: #1a1a1f;
  --border-strong: #36363e;

  --accent: #60a5fa;
  --accent-soft: rgba(96, 165, 250, 0.12);
  --emerald: #34d399;
  --emerald-soft: rgba(52, 211, 153, 0.12);
  --amber: #fbbf24;
  --amber-soft: rgba(251, 191, 36, 0.12);
  --rose: #fb7185;
  --rose-soft: rgba(251, 113, 133, 0.12);

  /* Syntax Highlighting (Refined Dark) */
  --syn-kw: #ff8787;
  --syn-fn: #b197fc;
  --syn-str: #66d9e8;
  --syn-num: #74c0fc;
  --syn-cmt: #6c757d;
  --syn-typ: #ffc078;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.25);
  --shadow-card: 0 2px 10px rgba(0, 0, 0, 0.35);
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.8;
  padding: 0 24px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

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

/* ==========================================================================
   Layout Wrapper
   ========================================================================== */
.wrapper {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 56px 0 96px;
  position: relative;
}

/* ==========================================================================
   Minimalist Header Navigation
   ========================================================================== */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 56px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border-subtle);
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-weight: 600;
  font-size: 0.98rem;
  letter-spacing: -0.02em;
}

.brand-mark {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  background: var(--text);
  color: var(--bg);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-sm);
  transition: transform 0.18s ease;
}

.site-brand:hover .brand-mark {
  transform: translateY(-1px);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  text-decoration: none;
  font-size: 0.86rem;
  color: var(--text-muted);
  padding: 5px 11px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background-color 0.15s ease;
}

.site-nav a:hover {
  color: var(--text);
  background: var(--bg-hover);
}

.site-nav a.active {
  color: var(--text);
  font-weight: 500;
  background: var(--bg-subtle);
}

.theme-btn {
  margin-left: 6px;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: all 0.15s ease;
}

.theme-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--bg-subtle);
}

/* ==========================================================================
   Editorial Year-Column Post Index (paco.me / rauno.me style)
   ========================================================================== */
.year-section {
  display: grid;
  grid-template-columns: 76px 1fr;
  align-items: baseline;
  padding: 20px 0;
  border-top: 1px solid var(--border-subtle);
}

.year-section:first-of-type {
  border-top: none;
  padding-top: 0;
}

.year-label {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
  padding-top: 9px;
  user-select: none;
}

.post-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* Dim non-hovered items softly when hovering the list */
.post-list:hover .post-row {
  opacity: 0.52;
}

.post-list:hover .post-row:hover {
  opacity: 1;
}

.post-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 9px 12px;
  margin: 0 -12px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text);
  transition: opacity 0.18s ease, background-color 0.15s ease;
}

.post-row:hover {
  background-color: var(--bg-hover);
}

.post-title {
  font-size: 0.96rem;
  font-weight: 450;
  line-height: 1.5;
  color: var(--text);
  transition: transform 0.15s ease;
}

.post-row:hover .post-title {
  transform: translateX(2px);
}

.post-leader {
  flex: 1;
  border-bottom: 1px dashed var(--border);
  min-width: 16px;
  transform: translateY(-4px);
  transition: border-color 0.15s ease;
}

.post-row:hover .post-leader {
  border-bottom-color: var(--border-strong);
}

.post-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  flex-shrink: 0;
  transition: color 0.15s ease;
}

.post-row:hover .post-date {
  color: var(--text-secondary);
}

/* ==========================================================================
   Tag Filter Pills (/tags/)
   ========================================================================== */
.tag-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 36px;
}

.tag-pill {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg-surface);
  color: var(--text-secondary);
  cursor: pointer;
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition: all 0.15s ease;
}

.tag-pill:hover {
  border-color: var(--border-strong);
  color: var(--text);
  transform: translateY(-1px);
}

.tag-pill.active {
  background: var(--text);
  border-color: var(--text);
  color: var(--bg);
}

.tag-pill span {
  opacity: 0.6;
  margin-left: 4px;
}

/* ==========================================================================
   Article Page Typography & Header
   ========================================================================== */
.back-nav {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  text-decoration: none;
  margin-bottom: 24px;
  padding: 4px 8px;
  margin-left: -8px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background-color 0.15s ease, transform 0.15s ease;
}

.back-nav:hover {
  color: var(--text);
  background: var(--bg-hover);
  transform: translateX(-2px);
}

.article-header {
  margin-bottom: 36px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--border);
}

.article-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
  font-variant-numeric: tabular-nums;
}

.article-tags {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
}

.meta-tag {
  color: var(--text-secondary);
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  padding: 1px 7px;
  border-radius: 5px;
  text-decoration: none;
  font-size: 0.74rem;
  transition: all 0.15s ease;
}

.meta-tag:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--border-subtle);
}

.article-title {
  font-size: 1.9rem;
  font-weight: 650;
  line-height: 1.32;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 0;
}

.article-lead {
  font-size: 1.02rem;
  line-height: 1.65;
  color: var(--text-secondary);
  margin-top: 12px;
  margin-bottom: 0;
}

/* ==========================================================================
   Desktop Margin Floating TOC & Mobile Collapsible TOC
   ========================================================================== */
.margin-toc {
  position: fixed;
  top: 128px;
  left: max(20px, calc(50% - 585px));
  width: 205px;
  max-height: calc(100vh - 170px);
  overflow-y: auto;
  scrollbar-width: none;
  font-size: 0.78rem;
  line-height: 1.45;
}

.margin-toc::-webkit-scrollbar {
  display: none;
}

.margin-toc-title {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-faint);
  margin-bottom: 10px;
}

.margin-toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
  border-left: 1px solid var(--border);
}

.margin-toc ul ul {
  border-left: none;
}

.margin-toc li {
  margin: 0;
}

.margin-toc a {
  display: block;
  padding: 4.5px 0 4.5px 12px;
  color: var(--text-muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  margin-left: -1px;
  transition: color 0.15s ease, border-color 0.15s ease;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.margin-toc ul ul a {
  padding-left: 22px;
  font-size: 0.74rem;
  color: var(--text-faint);
}

.margin-toc a code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: transparent;
  border: none;
  padding: 0;
  color: inherit;
}

.margin-toc a:hover {
  color: var(--text);
}

.margin-toc a.active {
  color: var(--text);
  font-weight: 500;
  border-left-color: var(--text);
}

/* Mobile / Tablet Collapsible TOC */
details.inline-toc {
  display: none;
  margin: 0 0 32px;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  font-size: 0.86rem;
}

details.inline-toc summary {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

details.inline-toc summary::-webkit-details-marker {
  display: none;
}

details.inline-toc summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-muted);
}

details.inline-toc[open] summary {
  padding-bottom: 10px;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--border-subtle);
}

details.inline-toc[open] summary::after {
  content: "−";
}

details.inline-toc ul {
  margin: 4px 0 2px;
  padding-left: 1.15rem;
}

details.inline-toc ul ul {
  margin: 3px 0;
  padding-left: 1.1rem;
  font-size: 0.82rem;
}

details.inline-toc li {
  margin-bottom: 4px;
}

details.inline-toc a {
  color: var(--text-secondary);
  text-decoration: none;
}

details.inline-toc a:hover {
  color: var(--text);
}

/* ==========================================================================
   Prose — High-Craft Markdown, LaTeX, Code & Diagrams
   ========================================================================== */
.prose {
  font-size: 16.25px;
  line-height: 1.84;
  color: var(--text);
  overflow-wrap: break-word;
}

.prose p {
  margin-bottom: 1.35em;
}

.prose strong {
  font-weight: 600;
  color: var(--text);
}

.prose a:not(.fn-ref):not(.fn-back):not(.footnote-ref):not(.footnote-backref) {
  color: var(--text);
  text-decoration: underline;
  text-decoration-color: var(--border-strong);
  text-underline-offset: 3.5px;
  transition: color 0.15s ease, text-decoration-color 0.15s ease;
}

.prose a:not(.fn-ref):not(.fn-back):not(.footnote-ref):not(.footnote-backref):hover {
  color: var(--accent);
  text-decoration-color: var(--accent);
}

.prose h1,
.prose h2 {
  font-size: 1.32rem;
  font-weight: 650;
  line-height: 1.4;
  letter-spacing: -0.02em;
  margin-top: 2.5em;
  margin-bottom: 0.85em;
  padding-bottom: 0.35em;
  border-bottom: 1px solid var(--border-subtle);
  scroll-margin-top: 32px;
}

.prose > h1:first-child,
.prose > h2:first-child {
  margin-top: 0.5em;
}

.prose h3 {
  font-size: 1.08rem;
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: -0.01em;
  margin-top: 2em;
  margin-bottom: 0.65em;
  scroll-margin-top: 32px;
}

.prose h4,
.prose h5,
.prose h6 {
  font-size: 0.96rem;
  font-weight: 600;
  margin-top: 1.5em;
  margin-bottom: 0.5em;
}

.sec-num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-right: 8px;
}

.prose ul,
.prose ol {
  padding-left: 1.4rem;
  margin-bottom: 1.4em;
}

.prose li {
  margin-bottom: 0.45em;
}

.prose li > p {
  margin-bottom: 0.6em;
}

.prose li > .code-block {
  margin: 0.85em 0 1.1em;
}

.prose hr {
  border: none;
  border-top: 1px dashed var(--border);
  margin: 2.4em 0;
}

/* Hide redundant <hr> when immediately followed by an h2 (which already has a bottom divider) */
.prose hr + h2 {
  margin-top: 0;
}
.prose hr:has(+ h2) {
  display: none;
}

.prose img {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  margin: 1.4em auto;
}

/* Collapsible Details Block inside Prose */
.prose details.code-details {
  margin: 1.75em 0;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.prose details.code-details summary {
  padding: 12px 16px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-code-bar);
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: color 0.15s ease, background-color 0.15s ease;
}

.prose details.code-details summary::-webkit-details-marker {
  display: none;
}

.prose details.code-details summary::after {
  content: "Expand ▾";
  font-size: 0.72rem;
  color: var(--text-muted);
}

.prose details.code-details summary:hover {
  color: var(--text);
}

.prose details.code-details[open] summary {
  border-bottom: 1px solid var(--border);
}

.prose details.code-details[open] summary::after {
  content: "Collapse ▴";
}

.prose details.code-details .code-block {
  margin: 0;
  border: none;
  border-radius: 0;
  box-shadow: none;
}

/* Inline Code */
:not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.84em;
  padding: 2px 6px;
  border-radius: 5px;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  color: var(--text);
  word-break: break-word;
}

.prose h1 code,
.prose h2 code,
.prose h3 code {
  font-size: 0.86em;
  padding: 2px 7px;
  vertical-align: middle;
}

/* Callout Box */
.callout {
  margin: 1.75em 0;
  padding: 15px 18px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  box-shadow: var(--shadow-card);
  font-size: 0.92rem;
  line-height: 1.72;
}

.callout-head {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  margin-bottom: 5px;
}

.callout p:last-child {
  margin-bottom: 0;
}

/* Math Formula Display Card */
.math-card {
  margin: 1.65em 0;
  padding: 18px 22px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.math-body {
  flex: 1;
  text-align: center;
  min-width: min-content;
}

.math-num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  flex-shrink: 0;
  user-select: none;
}

/* Code Block */
.code-block {
  margin: 1.65em 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-code);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.code-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 7px 14px;
  background: var(--bg-code-bar);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-secondary);
}

.code-bar-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.code-dots {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.code-dots i {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--border-strong);
  opacity: 0.75;
}

.code-title {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

.code-bar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.code-lang {
  font-size: 0.68rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 3px 8.5px;
  font-family: var(--font-mono);
  font-size: 0.71rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
}

.copy-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.copy-btn.copied {
  color: var(--emerald);
  border-color: var(--emerald);
  background: var(--emerald-soft);
}

.code-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding: 13px 0;
}

.code-line {
  display: flex;
  padding: 0 16px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.68;
  min-width: max-content;
}

.code-line:hover {
  background: var(--bg-hover);
}

.code-line.hl {
  background: var(--accent-soft);
  border-left: 2.5px solid var(--accent);
  padding-left: 13.5px;
}

.code-line.add {
  background: var(--emerald-soft);
  border-left: 2.5px solid var(--emerald);
  padding-left: 13.5px;
}

.code-line.del {
  background: var(--rose-soft);
  border-left: 2.5px solid var(--rose);
  padding-left: 13.5px;
  opacity: 0.85;
}

.ln {
  min-width: 28px;
  flex-shrink: 0;
  color: var(--text-faint);
  user-select: none;
  text-align: right;
  padding-right: 16px;
  font-variant-numeric: tabular-nums;
  opacity: 0.75;
}

.lc {
  white-space: pre;
  color: var(--text);
}

.tok-kw { color: var(--syn-kw); font-weight: 500; }
.tok-fn { color: var(--syn-fn); }
.tok-str { color: var(--syn-str); }
.tok-num { color: var(--syn-num); }
.tok-cmt { color: var(--syn-cmt); font-style: italic; }
.tok-typ { color: var(--syn-typ); }

/* Fallback for plain <pre><code> blocks */
.prose pre:not(.code-scroll) {
  margin: 1.65em 0;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-code);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.68;
}

/* Data Table */
.table-card {
  margin: 1.75em 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  box-shadow: var(--shadow-card);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  line-height: 1.6;
}

th, td {
  padding: 11px 15px;
  border-bottom: 1px solid var(--border-subtle);
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--bg-subtle);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--text-secondary);
  white-space: nowrap;
}

td:first-child {
  white-space: nowrap;
}

tbody tr:hover {
  background: var(--bg-hover);
}

tr:last-child td {
  border-bottom: none;
}

td.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* Blockquote */
blockquote {
  margin: 1.75em 0;
  padding: 12px 18px;
  border-left: 3px solid var(--border-strong);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--bg-subtle);
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

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

blockquote cite {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 0.76rem;
  color: var(--text-muted);
}

/* Footnotes */
.footnotes {
  margin-top: 3.2em;
  padding-top: 1.4em;
  border-top: 1px solid var(--border);
  font-size: 0.83rem;
  color: var(--text-secondary);
}

.fn-ref,
.footnote-ref {
  font-family: var(--font-mono);
  font-size: 0.74em;
  vertical-align: super;
  color: var(--accent);
  text-decoration: none;
  margin-left: 1px;
}

.fn-back,
.footnote-backref {
  text-decoration: none;
  color: var(--text-muted);
}

/* ==========================================================================
   Previous / Next Post Navigation
   ========================================================================== */
.post-nav {
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.post-nav-item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-surface);
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.15s ease, transform 0.15s ease, background-color 0.15s ease;
}

.post-nav-item:hover {
  border-color: var(--border-strong);
  background: var(--bg-subtle);
  transform: translateY(-1px);
}

.post-nav-item.next {
  text-align: right;
  align-items: flex-end;
}

.post-nav-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
}

.post-nav-title {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1.4;
}

/* ==========================================================================
   About Page Key-Value Grid
   ========================================================================== */
.kv-list {
  margin-top: 28px;
  border-top: 1px solid var(--border);
}

.kv-row {
  display: grid;
  grid-template-columns: 110px 1fr;
  padding: 13px 0;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.92rem;
}

.kv-key {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  padding-top: 2px;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  margin-top: 64px;
  padding-top: 22px;
  border-top: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.site-footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

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

/* ==========================================================================
   Responsive Design (Tablet & Mobile)
   ========================================================================== */
@media (max-width: 1180px) {
  .margin-toc {
    display: none;
  }
  details.inline-toc {
    display: block;
  }
}

@media (max-width: 600px) {
  body {
    padding: 0 18px;
  }

  .wrapper {
    padding: 32px 0 64px;
  }

  .site-header {
    margin-bottom: 36px;
  }

  .year-section {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 14px 0;
  }

  .year-label {
    padding-top: 0;
    font-size: 0.78rem;
  }

  .post-row {
    padding: 8px 0;
    margin: 0;
  }

  .post-leader {
    display: none;
  }

  .article-title {
    font-size: 1.52rem;
  }

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

  .post-nav-item.next {
    text-align: left;
    align-items: flex-start;
  }

  .math-card {
    padding: 14px;
  }

  .kv-row {
    grid-template-columns: 1fr;
    gap: 2px;
  }
}