/* ═══════════════════════════════════════════════════════════════
   ARBALEST — Engineer's Precision Notebook
   A blueprint-aesthetic reading experience.
   Theme: medieval crossbow weapon system — mechanical craftsmanship.
   ═══════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:ital,wght@0,400;0,600;1,400&family=JetBrains+Mono:ital,wght@0,300;0,400;0,500;1,400&family=Noto+Serif+TC:wght@400;600;900&display=swap');

/* ─── Custom Properties ─── */
:root {
  --bg: #0d1117;
  --bg-raised: #161b22;
  --copper: #c9884b;
  --copper-dim: rgba(201, 136, 75, 0.15);
  --steel: #6b8fa3;
  --parchment: #e8dcc8;
  --text-dim: #8b949e;
  --border: #30363d;
  --green-dim: #6b9e6b;
  --font-heading: 'JetBrains Mono', ui-monospace, monospace;
  --font-body: 'Crimson Pro', 'Noto Serif TC', 'Charter', 'Songti TC', serif;
  --font-caption: 'JetBrains Mono', ui-monospace, monospace;
  --font-display: 'Noto Serif TC', serif;
  --fs-body: clamp(1.05rem, 1rem + 0.25vw, 1.175rem);
  --fs-h1: clamp(1.5rem, 1.3rem + 1vw, 2rem);
  --fs-h2: clamp(1.25rem, 1.15rem + 0.5vw, 1.45rem);
  --fs-h3: clamp(1.08rem, 1.02rem + 0.25vw, 1.2rem);
  --fs-small: clamp(0.75rem, 0.7rem + 0.2vw, 0.85rem);
  --tracking-tight: -0.02em;
  --tracking-wide: 0.08em;
}

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

/* ─── Skip to content (a11y) ─── */
.skip-to-content {
  position: absolute; top: -100%; left: 1rem;
  background: var(--copper); color: var(--bg);
  padding: 0.5rem 1rem; font-family: var(--font-caption);
  font-size: var(--fs-small); z-index: 9999; text-decoration: none;
}
.skip-to-content:focus { top: 1rem; }

/* ─── Body & Blueprint Grid + Noise + Corner Marks ─── */
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--parchment);
  line-height: 1.8;
  font-size: var(--fs-body);
  font-feature-settings: 'kern' 1, 'liga' 1;
  text-rendering: optimizeLegibility;
  hanging-punctuation: first allow-end last;
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E"),
    repeating-linear-gradient(0deg, transparent, transparent 39px, rgba(48, 54, 61, 0.2) 39px, rgba(48, 54, 61, 0.2) 40px),
    repeating-linear-gradient(90deg, transparent, transparent 39px, rgba(48, 54, 61, 0.2) 39px, rgba(48, 54, 61, 0.2) 40px);
  -webkit-font-smoothing: antialiased;
  position: relative;
}

/* Corner registration marks */
body::before, body::after {
  content: ''; position: fixed; z-index: 9998; pointer-events: none;
  width: 20px; height: 20px;
  border-color: var(--copper); border-style: solid;
}
body::before { top: 12px; left: 12px; border-width: 2px 0 0 2px; }
body::after { bottom: 12px; right: 12px; border-width: 0 2px 2px 0; }

/* ─── Selection & Focus ─── */
::selection { background: var(--copper); color: var(--bg); }
:focus-visible { outline: 2px solid var(--copper); outline-offset: 3px; }

/* ─── Animation Keyframes ─── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

main { animation: fadeInUp 0.3s ease-out both; padding: 2rem 0; }

/* ─── Layout ─── */
.container {
  max-width: 680px;
  margin-left: max(2rem, calc(50vw - 400px));
  margin-right: 2rem;
}

/* ─── Surface Depth System ─── */
.surface-hero {
  background: color-mix(in srgb, var(--bg-raised) 92%, var(--copper));
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  border: 1px solid var(--border);
}
.surface-default {
  background: var(--bg-raised);
  border: 1px solid var(--border);
}
.surface-recessed {
  background: color-mix(in srgb, var(--bg) 90%, black);
  border: 1px solid var(--border);
}

/* ─── Header ─── */
.site-header { border-bottom: 1px solid var(--border); padding: 1rem 0; }
.nav-bar { display: flex; justify-content: space-between; align-items: center; min-height: 44px; }
.site-title {
  font-family: var(--font-heading); font-size: 1.1rem;
  color: var(--copper); text-decoration: none; letter-spacing: var(--tracking-wide);
  font-weight: 300;
}
.nav-links { display: flex; align-items: center; gap: 1.5rem; }
.nav-links > a {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--text-dim); text-decoration: none; transition: color 0.2s;
}
.nav-links > a:hover { color: var(--parchment); }
.lang-switch { display: flex; gap: 0.5rem; }
.lang-link {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--text-dim); text-decoration: none;
  padding: 0.3rem 0.5rem; min-height: 44px;
  display: inline-flex; align-items: center;
  border: 1px solid transparent; transition: color 0.2s, border-color 0.2s;
}
.lang-link:hover { color: var(--parchment); }
.lang-link.active { color: var(--copper); border-color: var(--copper); }

/* ─── Bolt Separator ─── */
.bolt-separator { height: 1px; background: var(--border); margin: 1.5rem 0; position: relative; }
.bolt-separator::before {
  content: "◆"; position: absolute; left: 50%; top: 50%;
  transform: translate(-50%, -50%); font-size: 0.5rem;
  color: var(--copper); background: var(--bg); padding: 0 0.5rem;
}

/* ─── Page Title ─── */
.page-title {
  font-family: var(--font-heading); font-size: var(--fs-h1);
  color: var(--parchment); font-weight: 300; letter-spacing: var(--tracking-tight); line-height: 1.3;
}

/* ─── Post List ─── */
.post-item {
  display: grid; grid-template-columns: auto 1fr; gap: 0.3rem 1rem;
  padding: 0.6rem 0; border-bottom: 1px solid var(--border);
  border-left: 2px solid transparent;
  padding-left: 0.5rem;
  animation: fadeInUp 0.3s ease-out both;
  transition: border-left-color 0.2s ease;
}
.post-item:hover { border-left-color: var(--copper); }
.post-item:nth-child(1) { animation-delay: 0.05s; }
.post-item:nth-child(2) { animation-delay: 0.1s; }
.post-item:nth-child(3) { animation-delay: 0.15s; }
.post-item:nth-child(4) { animation-delay: 0.2s; }
.post-item:nth-child(5) { animation-delay: 0.25s; }
.post-item:nth-child(n+6) { animation-delay: 0.3s; }
.post-item time {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--text-dim); white-space: nowrap;
}
.post-item h3 { grid-column: 2; margin: 0; }
.post-item .post-summary { grid-column: 2; margin: 0; font-size: var(--fs-small); color: var(--text-dim); }
.post-item a {
  color: var(--parchment); text-decoration: none; position: relative;
}
.post-item a::after {
  content: ''; position: absolute; bottom: -1px; left: 0;
  width: 0; height: 1px; background: var(--copper); transition: width 0.25s ease;
}
.post-item a:hover { color: var(--copper); }
.post-item a:hover::after { width: 100%; }

/* ─── Single Post Header ─── */
.post-header h1 {
  font-family: var(--font-display); font-size: var(--fs-h1);
  font-weight: 900; line-height: 1.3; color: var(--parchment);
  letter-spacing: var(--tracking-tight);
}
.post-meta {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--text-dim); margin-top: 0.5rem;
  display: flex; gap: 1.5rem; flex-wrap: wrap;
}

/* ─── Post Content ─── */
.post-content { counter-reset: heading2 heading3; }
.post-content p { margin: 1.5em 0; }

.post-content h2, .post-content h3, .post-content h4 {
  font-family: var(--font-heading); font-weight: 400;
  color: var(--parchment); line-height: 1.3; margin: 2.5rem 0 0.8rem; padding-bottom: 0.3rem;
}
.post-content h2 {
  font-size: var(--fs-h2); border-bottom: 1px solid var(--border);
  counter-increment: heading2; counter-reset: heading3;
  padding-left: 1.2rem; position: relative;
}
/* Gear icon for h2 */
.post-content h2::after {
  content: ''; position: absolute; left: 0; top: 0.35em;
  width: 12px; height: 12px; border-radius: 50%;
  border: 2px solid var(--copper);
  clip-path: polygon(50% 0%, 65% 25%, 100% 25%, 75% 50%, 85% 85%, 50% 70%, 15% 85%, 25% 50%, 0% 25%, 35% 25%);
}
.post-content h2::before {
  content: counter(heading2, decimal-leading-zero) ". ";
  color: var(--copper); font-size: 0.85em;
}
.post-content h3 { font-size: var(--fs-h3); counter-increment: heading3; }
.post-content h3::before {
  content: counter(heading2, decimal-leading-zero) "." counter(heading3) " ";
  color: var(--text-dim); font-size: 0.8em;
}
.post-content h4 { font-size: 1rem; }

/* Links: underline slides in from left */
.post-content a {
  color: var(--steel); text-decoration: none;
  background-image: linear-gradient(var(--copper), var(--copper));
  background-size: 0% 1px; background-repeat: no-repeat;
  background-position: left bottom;
  transition: background-size 0.25s ease, color 0.2s;
}
.post-content a:hover { color: var(--copper); background-size: 100% 1px; }

/* Lists with bolt-tip markers */
.post-content ul, .post-content ol { margin: 1.5em 0; padding-left: 1.5rem; }
.post-content li { margin: 0.4rem 0; }
.post-content ul li { list-style: none; position: relative; padding-left: 1rem; }
.post-content ul li::before { content: '▸'; position: absolute; left: -0.5rem; color: var(--copper); }
.post-content ol li::marker { color: var(--copper); font-family: var(--font-caption); font-size: 0.85em; }

/* Blockquote with hatch pattern */
.post-content blockquote {
  border-left: none; padding: 1rem 1.2rem 1rem 2rem;
  margin: 1.5rem 0; color: var(--text-dim);
  background: linear-gradient(90deg, var(--copper-dim), transparent 70%);
  font-style: italic; position: relative;
}
.post-content blockquote::before {
  content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 12px;
  background: repeating-linear-gradient(
    -45deg, transparent, transparent 3px,
    rgba(201, 136, 75, 0.2) 3px, rgba(201, 136, 75, 0.2) 4px
  );
}
.post-content blockquote p { margin: 0.5em 0; }

/* HR: dimension line with end caps */
.post-content hr {
  border: none; height: 1px; background: var(--border);
  margin: 2.5rem 2rem; position: relative;
}
.post-content hr::before, .post-content hr::after {
  content: ''; position: absolute; top: -4px;
  width: 1px; height: 9px; background: var(--copper);
}
.post-content hr::before { left: 0; }
.post-content hr::after { right: 0; }

/* ─── Code: Inline ─── */
.post-content code {
  font-family: var(--font-heading); font-size: 0.85em;
  background: var(--bg-raised); padding: 0.15em 0.4em;
  border-radius: 3px; border: 1px solid var(--border);
}

/* ─── Code Blocks ─── */
.post-content pre {
  background: var(--bg-raised); border: 1px solid var(--border);
  border-top: 2px solid var(--copper); border-radius: 2px;
  padding: 1.2rem 1.5rem 1.2rem 3rem;
  overflow-x: auto; margin: 1.5rem 0; position: relative;
  transition: box-shadow 0.2s ease;
}
.post-content pre:hover { box-shadow: 0 0 12px rgba(201, 136, 75, 0.05); }
.post-content pre::before, .post-content pre::after {
  content: ''; position: absolute; width: 8px; height: 8px;
  border-color: var(--copper); border-style: solid;
}
.post-content pre::before { top: 6px; left: 6px; border-width: 1px 0 0 1px; }
.post-content pre::after { bottom: 6px; right: 6px; border-width: 0 1px 1px 0; }
.post-content pre code {
  background: none; border: none; padding: 0;
  font-size: 0.85rem; line-height: 1.6; display: block;
  border-left: 1px solid var(--border); padding-left: 1rem; margin-left: -1.5rem;
}

/* Language label */
.highlight pre { position: relative; }
.highlight [data-lang]::before, .post-content pre[data-lang]::before {
  content: attr(data-lang); position: absolute; top: 0.4rem; right: 0.8rem;
  font-family: var(--font-caption); font-size: 0.65rem;
  color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.05em;
  border-width: 0; width: auto; height: auto;
}

/* Scrollbar */
.post-content pre::-webkit-scrollbar { height: 4px; }
.post-content pre::-webkit-scrollbar-track { background: transparent; }
.post-content pre::-webkit-scrollbar-thumb { background: var(--copper); border-radius: 2px; }

/* ─── Tables ─── */
.table-wrapper { overflow-x: auto; margin: 1.5rem 0; }
.post-content table { width: 100%; border-collapse: collapse; margin: 1.5rem 0; font-size: 0.9rem; }
.post-content th, .post-content td {
  padding: 0.7rem 0.8rem; text-align: left; border-bottom: 1px solid var(--border);
}
.post-content th {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--copper); font-weight: 400; letter-spacing: 0.03em;
  border-bottom: 2px solid var(--copper);
}
.post-content tr:nth-child(even) { background: rgba(22, 27, 34, 0.5); }
.post-content tr:hover { background: var(--copper-dim); }

/* ─── Images ─── */
.post-content img { max-width: 100%; height: auto; border-radius: 2px; margin: 1.5rem 0; }

/* ─── TOC Links ─── */
.toc a {
  transition: padding-left 0.2s ease, color 0.2s;
  text-decoration: none; color: var(--text-dim);
}
.toc a:hover { padding-left: 0.3rem; color: var(--copper); }

/* ─── Callout Boxes ─── */
.callout {
  border-left: 3px solid var(--border); padding: 1rem 1.2rem 1rem 1.5rem;
  margin: 1.5rem 0; background: var(--bg-raised); position: relative;
}
.callout::before {
  font-family: var(--font-caption); font-size: 0.6rem;
  text-transform: uppercase; letter-spacing: 0.08em;
  position: absolute; top: 0.5rem; left: 1.5rem; color: var(--text-dim);
}
.callout-decision { border-left-color: var(--copper); }
.callout-decision::before { content: 'decision'; color: var(--copper); }
.callout-constraint { border-left-color: var(--steel); }
.callout-constraint::before { content: 'constraint'; color: var(--steel); }
.callout-observation { border-left-color: var(--green-dim); }
.callout-observation::before { content: 'observation'; color: var(--green-dim); }

/* ─── Pull Quotes ─── */
.pull-quote {
  font-size: 1.3em; font-style: italic; border-left: 4px solid var(--copper);
  padding: 1rem 1.5rem; margin: 2rem 0; position: relative; color: var(--parchment);
}
.pull-quote::after {
  content: '"'; position: absolute; bottom: -0.3rem; right: 0.5rem;
  font-size: 4rem; color: var(--copper); opacity: 0.15; line-height: 1;
}

/* ─── Sidenotes ─── */
.sidenote {
  font-size: var(--fs-small); color: var(--steel);
  padding: 0.5rem 0; margin: 0.5rem 0 0.5rem 1.5rem;
  border-top: 1px solid var(--border);
}
@media (min-width: 901px) {
  .sidenote {
    float: right; clear: right; position: relative;
    margin-right: -200px; width: 180px; margin-left: 1rem;
  }
}

/* ─── Homepage Hero ─── */
.hero { text-align: center; padding: 2rem 0 1rem; }
.hero-image {
  width: 100%; max-width: 720px; height: auto; margin-bottom: 1.5rem;
  opacity: 0.9; border-radius: 4px;
}
.hero .site-title {
  font-family: var(--font-display); font-size: clamp(1.6rem, 1.4rem + 1.2vw, 2.4rem);
  font-weight: 900; color: var(--parchment); letter-spacing: var(--tracking-tight);
  display: block; margin-bottom: 0.5rem;
}
.site-tagline {
  font-family: var(--font-body); font-size: clamp(0.95rem, 0.9rem + 0.2vw, 1.1rem);
  color: var(--text-dim); font-style: italic;
}
.about-blurb { text-align: center; margin-bottom: 2rem; }
.attribution {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--text-dim); letter-spacing: var(--tracking-wide);
}
.latest-posts h2, .series-roadmap h2 {
  font-family: var(--font-heading); font-size: var(--fs-small);
  color: var(--copper); letter-spacing: var(--tracking-wide);
  text-transform: uppercase; margin-bottom: 1rem;
}
.view-all-nav { margin-top: 2rem; }
.view-all {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--steel); text-decoration: none;
  transition: color 0.2s;
}
.view-all:hover { color: var(--copper); }

/* ─── Roadmap Cards ─── */
.roadmap-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 1rem; margin: 1.5rem 0; counter-reset: roadmap;
}
.roadmap-card {
  border: 1px solid var(--border); padding: 1rem 1.2rem;
  background: var(--bg-raised); counter-increment: roadmap;
  animation: fadeInUp 0.3s ease-out both;
}
.roadmap-card::before {
  content: counter(roadmap, decimal-leading-zero);
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--text-dim); display: block; margin-bottom: 0.3rem;
}
.roadmap-card:nth-child(1) { animation-delay: 0.08s; }
.roadmap-card:nth-child(2) { animation-delay: 0.16s; }
.roadmap-card:nth-child(3) { animation-delay: 0.24s; }
.roadmap-card:nth-child(4) { animation-delay: 0.32s; }
.roadmap-card:nth-child(n+5) { animation-delay: 0.4s; }
.roadmap-card h3 { font-family: var(--font-display); font-size: 1rem; font-weight: 600; color: var(--parchment); margin-bottom: 0.2rem; }
.roadmap-card p { font-size: var(--fs-small); color: var(--text-dim); }
.roadmap-card[data-status='published'] { border-left: 3px solid var(--copper); }
.roadmap-card[data-status='upcoming'] { border-left: 3px solid var(--border); opacity: 0.7; }

/* ─── Footer ─── */
.site-footer { padding: 2rem 0; margin-top: 3rem; border-top: 1px solid var(--border); }
.site-footer p { font-family: var(--font-caption); font-size: 0.75rem; color: var(--text-dim); }

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════════════════ */
@media (max-width: 900px) {
  .container { margin-left: max(1.5rem, calc(50vw - 380px)); margin-right: 1.5rem; }
  .roadmap-grid { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .container { max-width: 100%; margin-left: auto; margin-right: auto; padding: 0 1.25rem; }
  .post-item { grid-template-columns: 1fr; gap: 0.2rem; }
  .post-item h3 { grid-column: 1; }
  .post-item .post-summary { grid-column: 1; }
  .post-header h1 { font-size: clamp(1.2rem, 1rem + 1vw, 1.5rem); }
  .nav-bar { min-height: 44px; }
  .lang-link { min-height: 44px; min-width: 44px; justify-content: center; }
  .post-content pre { padding-left: 1.5rem; }
  .post-content pre code { margin-left: -0.5rem; }
}

/* ═══════════════════════════════════════════════════════════════
   REDUCED MOTION
   ═══════════════════════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ═══════════════════════════════════════════════════════════════
   LIGHT MODE
   ═══════════════════════════════════════════════════════════════ */
@media (prefers-color-scheme: light) {
  :root {
    --bg: #faf6f0; --bg-raised: #f0ebe3;
    --parchment: #2d2a26; --text-dim: #5a5a5a;
    --border: #d4cbb8; --copper-dim: rgba(201, 136, 75, 0.08);
  }
  body {
    background-image:
      url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23n)' opacity='0.02'/%3E%3C/svg%3E"),
      repeating-linear-gradient(0deg, transparent, transparent 39px, rgba(180, 170, 150, 0.12) 39px, rgba(180, 170, 150, 0.12) 40px),
      repeating-linear-gradient(90deg, transparent, transparent 39px, rgba(180, 170, 150, 0.12) 39px, rgba(180, 170, 150, 0.12) 40px);
  }
  .post-content hr::before, .post-content hr::after { background: var(--copper); }
  .bolt-separator::before { background: var(--bg); }
  .post-content pre code { border-left-color: var(--border); }
  .callout { background: color-mix(in srgb, var(--bg-raised) 95%, white); }
  .post-content pre { background: color-mix(in srgb, var(--bg-raised) 90%, white); }
  body::before, body::after { border-color: color-mix(in srgb, var(--copper) 60%, transparent); }
}

/* ═══════════════════════════════════════════════════════════════
   PRINT
   ═══════════════════════════════════════════════════════════════ */
@media print {
  body {
    background: white !important; color: black;
    background-image: none !important; font-size: 11pt; line-height: 1.6;
  }
  body::before, body::after { display: none; }
  .site-header, .site-footer, .lang-switch, .bolt-separator { display: none; }
  .container { max-width: 100%; margin: 0; padding: 0; }
  .post-content a { color: black; background-image: none; }
  .post-content a[href^="http"]::after {
    content: " (" attr(href) ")"; display: inline;
    font-size: 0.8em; color: #555;
  }
  .post-content pre {
    border: 1px solid #ccc; border-top: 1px solid #ccc;
    page-break-inside: avoid; box-shadow: none;
  }
  .post-content pre::before, .post-content pre::after { display: none; }
  .post-content h2, .post-content h3 { page-break-after: avoid; }
  .post-content h2::after { display: none; }
  .post-content h2::before, .post-content h3::before { color: #666; }
  .post-content blockquote::before { display: none; }
  article { page-break-before: always; }
  article:first-of-type { page-break-before: avoid; }
}

/* ─── Post Tags ─── */
.post-tags { margin-top: 2.5rem; padding-top: 1.5rem; border-top: 1px solid var(--border); }
.tag-list { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tag-list li a {
  font-family: var(--font-caption); font-size: var(--fs-small);
  color: var(--steel); background: var(--copper-dim);
  padding: 0.2rem 0.6rem; border-radius: 3px;
  text-decoration: none; transition: color 0.2s, background 0.2s;
}
.tag-list li a:hover { color: var(--copper); background: rgba(201, 136, 75, 0.25); }

/* ─── Post Navigation ─── */
.post-nav {
  margin-top: 2rem; display: flex; justify-content: space-between;
  font-family: var(--font-caption); font-size: var(--fs-small);
}
.post-nav .prev, .post-nav .next {
  color: var(--steel); text-decoration: none; transition: color 0.2s;
}
.post-nav .prev:hover, .post-nav .next:hover { color: var(--copper); }
.post-nav .next { margin-left: auto; }