/* Rick Mark design system: graphite and paper, with signal amber and probe teal */
:root {
  --surface: #f6f5f1;
  --surface-raised: #ffffff;
  --hairline: #d9d7d0;
  --ink: #1b1c1e;
  --ink-muted: #5a5d63;
  --accent: #a8500a;
  --on-accent: #ffffff;
  --signal: #0b6874;
  --accent-tint: #f3e3cf;

  --font-sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 32px;
  --space-4: 64px;

  --radius-sm: 2px;
  --radius-md: 6px;
  --radius-lg: 12px;

  /* Graphite band (footer, header mark): fixed dark ground in both themes */
  --band-bg: #1b1c1e;
  --band-text: #ecebe6;
  --band-muted: #9b9ea4;
  --band-accent: #f0a53a;
  --band-dot: #2c2f33;
  --band-raised: #2c2f33;
  --band-signal: #5cc6d2;
  --band-paper: #f6f5f1;

  --max-width: 760px;
  --wide-width: 1040px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --surface: #111214;
    --surface-raised: #1a1c1f;
    --hairline: #2c2f33;
    --ink: #ecebe6;
    --ink-muted: #9b9ea4;
    --accent: #f0a53a;
    --on-accent: #1b1c1e;
    --signal: #5cc6d2;
    --accent-tint: #2e2416;
    --band-bg: #1a1c1f;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 28px;
  background: var(--surface);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 120ms ease;
}
a:hover { text-decoration: underline; text-underline-offset: 3px; }

:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-2); }

/* Type styles */
.label, .section-title {
  font-family: var(--font-mono);
  font-size: 12px; line-height: 16px; font-weight: 500;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ink-muted);
}

/* Header and footer */
.site-header {
  border-top: 4px solid var(--accent);
  border-bottom: 1px solid var(--hairline);
  background: var(--surface-raised);
}
.header-row, .footer-row {
  display: flex; flex-wrap: wrap; gap: var(--space-1) 24px;
  align-items: center; justify-content: space-between;
}
.header-row { min-height: 64px; }
.site-title {
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 24px; line-height: 32px; font-weight: 600;
  color: var(--ink);
}
.mark { width: 24px; height: 24px; flex: none; }
.site-title:hover { text-decoration: none; }
.site-nav { display: flex; gap: 24px; font-size: 15px; }
.site-nav a { color: var(--ink-muted); }
.site-nav a:hover { color: var(--ink); text-decoration: none; }
.site-nav a { padding: 4px 0; border-bottom: 2px solid transparent; }
.site-nav a.active { color: var(--accent); border-bottom-color: var(--accent); }

.site-main { padding-top: var(--space-3); padding-bottom: var(--space-4); }

.site-footer {
  padding: var(--space-4) 0 var(--space-3);
  background-color: var(--band-bg);
  background-image: radial-gradient(circle, var(--band-dot) 2.5px, transparent 3px);
  background-size: var(--space-3) var(--space-3);
  background-position: right -16px top -16px;
  border-top: 4px solid var(--signal);
  color: var(--band-muted);
  font-size: 14px; line-height: 20px;
}
.directory {
  display: grid; grid-template-columns: 1fr 1fr 2fr 1fr; gap: var(--space-3);
  padding-bottom: var(--space-3); margin-bottom: var(--space-2);
  border-bottom: 1px solid var(--band-raised);
}
.directory h2 { margin: 0 0 12px; color: var(--band-accent); }
.directory ul { list-style: none; margin: 0; padding: 0; }
.directory li { margin: 0 0 10px; }
.directory li span { display: block; color: var(--band-muted); font-size: 13px; line-height: 18px; }
.directory a { display: inline-flex; align-items: center; gap: 6px; color: var(--band-text); }
.directory a:hover { color: var(--band-accent); }
.directory code { font-family: var(--font-mono); font-size: 13px; }
.directory-projects ul { columns: 2; column-gap: var(--space-3); }
.directory-projects li { margin-bottom: 6px; break-inside: avoid; }
.footer-bottom { padding-top: 0; }
.footer-top { color: var(--band-muted); }
.footer-top:hover { color: var(--band-accent); }
.footer-brand { display: inline-flex; align-items: center; gap: var(--space-1); color: var(--band-text); }
.footer-brand .mark { width: 16px; height: 16px; }
.site-footer .b-ink { fill: var(--band-text); }
.icon { width: 16px; height: 16px; flex: none; }

/* Colour blocks shared by the hero, mark and rules */
.b-ink { fill: var(--ink); }
.b-accent { fill: var(--accent); }
.b-signal { fill: var(--signal); }
.b-tint { fill: var(--accent-tint); }
.b-dot { fill: var(--ink-muted); }
.b-dot-light { fill: var(--surface); }

/* Full-bleed colour bands */
.band { position: relative; overflow: hidden; }
.band-graphite { background: var(--band-bg); color: var(--band-text); }
.band-graphite .lead { color: var(--band-muted); }
.band-graphite a:not(.button) { color: var(--band-accent); }
.band-graphite .label-accent { color: var(--band-accent); }
.band-graphite :focus-visible { outline-color: var(--band-signal); }
.band-tint { background: var(--accent-tint); }
.wide { max-width: var(--wide-width); margin: 0 auto; padding: 0 var(--space-2); }

/* Fixed colours for art on the graphite band */
.g-accent { fill: var(--band-accent); }
.g-signal { fill: var(--band-signal); }
.g-paper { fill: var(--band-paper); }
.g-raised { fill: var(--band-raised); }
.g-dot { fill: var(--band-muted); }
.g-dot-dark { fill: var(--band-bg); }

.hero-inner {
  max-width: var(--wide-width); margin: 0 auto; padding: 0 var(--space-2);
  display: grid; grid-template-columns: minmax(0, 1fr) 400px; gap: var(--space-3);
  align-items: center;
}
.hero-text { padding: var(--space-4) 0; }
.hero-text h1, .about-hero-text h1 {
  font-size: 56px; line-height: 60px; font-weight: 600; letter-spacing: -0.02em;
  margin: var(--space-1) 0 var(--space-2);
}
.hero-art { align-self: center; height: 300px; }
.hero-art .blocks { display: block; overflow: visible; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2); margin: var(--space-3) 0 0; }
.band-graphite .button { background: var(--band-accent); color: var(--band-bg); }
.band-graphite .button:hover { background: var(--band-paper); color: var(--band-bg); }

/* Home: feature cards on the tint band */
.band-tint > .wide { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.band-intro { margin: 0 0 var(--space-3); font-size: 19px; line-height: 30px; max-width: 60ch; }
.features { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-2); }
.feature {
  display: flex; flex-direction: column;
  background: var(--surface-raised); color: var(--ink);
  border: 1px solid var(--hairline); border-radius: var(--radius-md); overflow: hidden;
}
.feature:hover { text-decoration: none; border-color: var(--ink); }
.feature-top {
  display: flex; align-items: flex-end; height: 96px; padding: var(--space-2);
  background-image: radial-gradient(circle, rgba(255, 255, 255, 0.22) 2.5px, transparent 3px);
  background-size: var(--space-3) var(--space-3);
}
.feature-top .label { color: inherit; }
.feature-signal .feature-top { background-color: #0b6874; color: #ffffff; }
.feature-accent .feature-top { background-color: #a8500a; color: #ffffff; }
.feature-ink .feature-top { background-color: var(--band-bg); color: var(--band-accent); }
.feature-body { padding: var(--space-2); font-size: 15px; line-height: 24px; color: var(--ink-muted); }
.feature-body strong { display: block; margin-bottom: 4px; font-size: 19px; line-height: 28px; font-weight: 600; color: var(--ink); }
.feature-body code { font-family: var(--font-mono); font-size: 17px; color: var(--signal); }

/* Home: projects grid on the graphite band */
.projects-band > .wide { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.section-title-band { color: var(--band-accent); margin-top: 0; }
.section-title-band::before { background: var(--band-accent); }
.projects-band .band-intro { color: var(--band-text); }
.project-grid {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-2);
}
.project {
  display: flex; flex-direction: column; gap: 4px; height: 100%;
  padding: var(--space-2); border-radius: var(--radius-md);
  background: var(--band-raised); color: var(--band-text);
  border-top: 4px solid var(--band-signal);
  transition: background-color 120ms ease;
}
.project-grid li:nth-child(3n+2) .project { border-top-color: var(--band-accent); }
.project-grid li:nth-child(3n) .project { border-top-color: var(--band-paper); }
.band-graphite a.project { color: var(--band-text); }
.project:hover { text-decoration: none; background: #3a3d42; }
.project-group { font-family: var(--font-mono); font-size: 12px; line-height: 16px; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; color: var(--band-muted); }
.project code { font-family: var(--font-mono); font-size: 16px; line-height: 24px; font-weight: 500; color: var(--band-signal); overflow-wrap: anywhere; }
.project-note { font-size: 14px; line-height: 20px; color: var(--band-text); }

/* Posts: cross-links after the article */
.more-from { margin-top: var(--space-4); }
.chips { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: var(--space-1); }
.chips a {
  display: inline-block; padding: 6px 12px; border-radius: var(--radius-md);
  background: var(--accent-tint); color: var(--ink); font-size: 14px; line-height: 20px;
}
.chips a:hover { text-decoration: none; background: var(--accent); color: var(--on-accent); }
.chips code { font-family: var(--font-mono); font-size: 13px; }

/* Page and post title bands */
.page-band .container { padding-top: var(--space-4); padding-bottom: var(--space-3); }
.page-band .page-title { margin: var(--space-1) 0 0; }
.page-band .rule-blocks { margin: var(--space-2) 0 0; }
.page-band .lead { margin: var(--space-2) 0 0; color: var(--ink); }
.post-band .post-meta .label { margin: 0; }

/* About: portrait and stats on the graphite band */
.about-hero-inner {
  display: grid; grid-template-columns: 280px minmax(0, 1fr); gap: var(--space-4);
  align-items: center; padding-top: var(--space-4); padding-bottom: var(--space-3);
}
.about-hero-text h1 { margin-top: var(--space-1); }
.portrait { position: relative; margin: 0; width: 280px; height: 280px; }
.portrait img {
  position: relative; display: block; width: 240px; height: 240px; object-fit: cover;
  border-radius: var(--radius-lg);
}
.portrait-block { position: absolute; border-radius: var(--radius-lg); }
.portrait-block-accent { right: 0; bottom: 0; width: 200px; height: 200px; background: var(--band-accent); }
.portrait-block-signal { left: -24px; top: 160px; width: 64px; height: 96px; background: var(--band-signal); border-radius: var(--radius-md); }
.stats {
  list-style: none; margin: 0; padding: 0 0 var(--space-4);
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-2);
}
.stat {
  display: flex; flex-direction: column; justify-content: space-between; gap: var(--space-2);
  min-height: 136px; padding: var(--space-2); border-radius: var(--radius-md);
}
.stat strong { font-size: 40px; line-height: 44px; font-weight: 600; letter-spacing: -0.02em; }
.stat span { font-family: var(--font-mono); font-size: 12px; line-height: 16px; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; }
.stat code { font: inherit; text-transform: none; }
.stat-accent { background: var(--band-accent); color: var(--band-bg); }
.stat-signal { background: var(--band-signal); color: var(--band-bg); }
.stat-paper { background: var(--band-paper); color: var(--band-bg); }
.stat-raised { background: var(--band-raised); color: var(--band-text); }

.button {
  display: inline-block; padding: 10px 20px;
  background: var(--accent); color: var(--on-accent);
  border-radius: var(--radius-md); font-weight: 600; font-size: 15px; line-height: 20px;
  transition: background-color 120ms ease;
}
.button:hover { text-decoration: none; background: var(--ink); color: var(--surface); }
.button-quiet { font-weight: 500; font-size: 15px; }

.label-accent { color: var(--accent); margin: 0; }

.rule-blocks { display: flex; gap: 4px; margin: var(--space-2) 0 var(--space-3); }
.rule-blocks span { height: 6px; border-radius: 1px; }
.rule-blocks span:nth-child(1) { width: 48px; background: var(--accent); }
.rule-blocks span:nth-child(2) { width: 16px; background: var(--signal); }
.rule-blocks span:nth-child(3) { width: 96px; background: var(--ink); }

/* Home and lists */
.lead { font-size: 19px; line-height: 30px; color: var(--ink-muted); max-width: 68ch; }
.section-title {
  display: flex; align-items: center; gap: var(--space-1);
  margin: var(--space-3) 0 var(--space-1);
}
.section-title::before {
  content: ""; width: 10px; height: 10px; flex: none;
  background: var(--signal); border-radius: var(--radius-sm);
}

.page-title {
  font-size: 36px; line-height: 42px; font-weight: 600; letter-spacing: -0.01em;
  margin: 0 0 var(--space-2);
}

.post-list { list-style: none; margin: 0 0 var(--space-2); padding: 0; border-top: 1px solid var(--hairline); }
.post-list li {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px var(--space-2);
  padding: 12px var(--space-1); margin: 0 calc(-1 * var(--space-1));
  border-bottom: 1px solid var(--hairline);
  transition: background-color 120ms ease;
}
.post-list li:hover { background: var(--accent-tint); }
.post-list time {
  flex: 0 0 7.5em;
  font-family: var(--font-mono); font-size: 13px; line-height: 20px;
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}
.post-list a { flex: 1 1 18em; color: var(--ink); font-weight: 500; }
.post-list a:hover { color: var(--accent); text-decoration: none; }

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px; line-height: 16px; font-weight: 500;
  letter-spacing: 0.04em; text-transform: uppercase;
  padding: 2px 6px; border-radius: var(--radius-sm);
  background: var(--signal);
  color: var(--surface);
}

/* Articles */
.prose { overflow-wrap: anywhere; }
.prose > p, .prose > ul, .prose > ol, .prose > blockquote { max-width: 68ch; }
.prose h1 {
  font-size: 36px; line-height: 42px; font-weight: 600; letter-spacing: -0.01em;
  margin: 0 0 24px;
}
.prose h2 { font-size: 24px; line-height: 32px; font-weight: 600; margin: 48px 0 12px; }
.prose h2::before {
  content: ""; display: inline-block; width: 10px; height: 10px;
  margin-right: 12px; vertical-align: 0.12em;
  background: var(--accent); border-radius: var(--radius-sm);
}
.prose ul > li::marker { color: var(--accent); }
.prose ::selection, ::selection { background: var(--accent-tint); }
.prose h3 { font-size: 19px; line-height: 28px; font-weight: 600; margin: var(--space-3) 0 var(--space-1); }
.prose h4 { font-size: 17px; line-height: 28px; font-weight: 600; margin: 24px 0 var(--space-1); }
.prose p, .prose ul, .prose ol, .prose table, .prose pre, .prose blockquote { margin: 0 0 var(--space-2); }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li { margin: 4px 0; }
.prose li > ul, .prose li > ol { margin: 4px 0 0; }
.prose img {
  max-width: 100%; height: auto; display: block; margin: var(--space-1) auto;
  border: 1px solid var(--hairline); border-radius: var(--radius-md);
}
.prose em:only-child { color: var(--ink-muted); }
.prose hr { border: 0; border-top: 1px solid var(--hairline); margin: var(--space-3) 0; }
.prose blockquote {
  padding: 12px var(--space-2);
  background: var(--accent-tint); border-radius: var(--radius-md);
  color: var(--ink);
}
.prose blockquote > :last-child { margin-bottom: 0; }

.prose code {
  font-family: var(--font-mono); font-size: 0.85em;
  color: var(--signal);
  background: var(--surface-raised); border: 1px solid var(--hairline);
  padding: 0.1em 0.35em; border-radius: var(--radius-sm); overflow-wrap: anywhere;
}
.prose pre {
  background: var(--surface-raised); border: 1px solid var(--hairline); border-radius: var(--radius-md);
  padding: 12px var(--space-2); overflow-x: auto;
  font-size: 14px; line-height: 22px;
}
.prose pre code {
  color: var(--ink); background: none; border: 0; padding: 0;
  font-size: 14px; overflow-wrap: normal;
}
.prose .highlighter-rouge .highlight { background: none; }

.prose table {
  display: block; overflow-x: auto; border-collapse: collapse;
  font-size: 14px; line-height: 20px;
}
.prose th, .prose td { border: 1px solid var(--hairline); padding: var(--space-1) 12px; text-align: left; vertical-align: top; }
.prose th { background: var(--surface-raised); font-weight: 600; }

.post-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-1);
  margin: 0;
}
.post-meta time {
  font-family: var(--font-mono); font-size: 13px; line-height: 20px;
  color: var(--signal);
}
.post-cover { margin: 0 0 var(--space-3) !important; width: 100%; }

.post-nav {
  display: flex; justify-content: space-between; gap: 24px;
  margin-top: var(--space-4); padding-top: var(--space-2);
  border-top: 1px solid var(--hairline);
  font-size: 15px; line-height: 24px;
}
.post-nav a:last-child { text-align: right; }

@media (max-width: 860px) {
  .features { grid-template-columns: 1fr; }
  .project-grid { grid-template-columns: 1fr 1fr; }
  .directory { grid-template-columns: 1fr 1fr; }
  .directory-projects { grid-column: 1 / -1; }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .about-hero-inner { grid-template-columns: 1fr; gap: var(--space-3); }
  .hero-inner { grid-template-columns: 1fr; gap: 0; }
  .hero-text { padding: var(--space-3) 0 var(--space-3); order: 2; }
  .hero-art { order: 1; height: 120px; overflow: hidden; margin: 0 calc(-1 * var(--space-2)); }
  .hero-art .blocks { transform: translateY(-40px); }
}

@media (max-width: 600px) {
  .project-grid { grid-template-columns: 1fr; }
  .hero-text h1, .about-hero-text h1 { font-size: 40px; line-height: 44px; }
  .stat strong { font-size: 32px; line-height: 36px; }
  body { font-size: 16px; line-height: 26px; }
  .prose h1, .page-title { font-size: 28px; line-height: 34px; }
  .site-title { font-size: 20px; line-height: 28px; }
  .post-nav { flex-direction: column; }
  .post-nav a:last-child { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  a { transition: none; }
}