/* =========================================================
   ProductHarness — Shared Stylesheet
   Design system: rose/violet/amber, dark default, light optional
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,700;1,400&family=DM+Mono:wght@300;400&family=DM+Sans:wght@300;400;500&display=swap');

/* =========================================================
   DESIGN TOKENS
   ========================================================= */

:root {
  /* Backgrounds */
  --bg:          #0e0c0d;
  --bg2:         #141214;
  --bg3:         #1c191b;
  --surface:     #181518;
  --border:      #2a2529;
  --dot-color:   rgba(255,255,255,0.04);

  /* Text */
  --text:        #ede9ec;
  --text-dim:    #8f8489;
  --text-muted:  #57494f;

  /* Accent colors */
  --accent:      #f472b6;
  --accent-dim:  #ec4899;
  --accent-glow: rgba(244, 114, 182, 0.12);
  --accent-2:    #a855f7;
  --accent-3:    #f59e0b;
  --accent-warn: #f59e0b;

  /* Layout */
  --read:        840px;

  /* Fonts */
  --font-serif:  'Playfair Display', Georgia, serif;
  --font-mono:   'DM Mono', monospace;
  --font-body:   'DM Sans', system-ui, sans-serif;
}

html[data-theme="light"] {
  --bg:          #fdf8fa;
  --bg2:         #ffffff;
  --bg3:         #f5eef2;
  --surface:     #ffffff;
  --border:      #ddd0d7;

  --text:        #1a0f14;
  --text-dim:    #5c5058;
  --text-muted:  #7a6f72;

  --accent:      #be185d;
  --accent-dim:  #9f1239;
  --accent-glow: rgba(190, 24, 93, 0.08);
  --dot-color:   rgba(0,0,0,0.07);
}

/* =========================================================
   BASE
   ========================================================= */

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

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.7;
  font-size: 1rem;
}

/* Noise texture overlay */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1000;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 512 512' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 256px 256px;
}

a { color: inherit; }

p { margin-bottom: 1.25rem; }
p:last-child { margin-bottom: 0; }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 400;
  line-height: 1.2;
}

/* =========================================================
   NAVIGATION
   ========================================================= */

#nav {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(5px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 60px;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  text-decoration: none;
  flex-shrink: 0;
}

.nav-logo:hover { color: var(--accent-dim); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  margin-left: auto;
}

.nav-link {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1.25rem;
  cursor: pointer;
  padding: 0.25rem;
  line-height: 1;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.9rem;
  cursor: pointer;
  padding: 0.3rem 0.5rem;
  border-radius: 3px;
  transition: color 0.2s, border-color 0.2s;
  line-height: 1;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* =========================================================
   LAYOUT
   ========================================================= */

main {
  padding-top: 60px;
}

.container {
  width: 100%;
  max-width: var(--read);
  margin: 0 auto;
  padding: 0 2rem;
}

.container-wide {
  max-width: 1020px;
  margin: 0 auto;
  padding: 0 2rem;
}

section {
  padding: 5rem 0;
  background-image: radial-gradient(circle, var(--dot-color) 1px, transparent 1px);
  background-size: 28px 28px;
}

section:nth-child(even) {
  background-color: var(--bg2);
  background-image: radial-gradient(circle, var(--dot-color) 1px, transparent 1px);
  background-size: 28px 28px;
}

/* =========================================================
   SECTION ANATOMY
   ========================================================= */

.section-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 2.25rem;
  font-weight: 400;
  line-height: 1.2;
  color: var(--text);
  margin-bottom: 1.5rem;
}

.section-body {
  color: var(--text-dim);
  font-size: 1.05rem;
}

.section-sub {
  color: var(--text-dim);
  font-size: 1rem;
  margin-bottom: 2rem;
  margin-top: -0.5rem;
}

/* =========================================================
   HERO
   ========================================================= */

.hero {
  min-height: 60vh;
  display: flex;
  align-items: center;
  padding: 8rem 0 5rem;
  background:
    radial-gradient(ellipse 75% 65% at 12% 60%, rgba(244, 114, 182, 0.11) 0%, transparent 65%),
    radial-gradient(ellipse 55% 55% at 88% 20%, rgba(168, 85, 247, 0.07) 0%, transparent 65%),
    radial-gradient(circle, var(--dot-color) 1px, transparent 1px),
    var(--bg);
  background-size: auto, auto, 28px 28px, auto;
}

html[data-theme="light"] .hero {
  background:
    radial-gradient(ellipse 75% 65% at 12% 60%, rgba(190, 24, 93, 0.06) 0%, transparent 65%),
    radial-gradient(ellipse 55% 55% at 88% 20%, rgba(147, 51, 234, 0.04) 0%, transparent 65%),
    radial-gradient(circle, var(--dot-color) 1px, transparent 1px),
    var(--bg);
  background-size: auto, auto, 28px 28px, auto;
}

.hero-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 400;
  line-height: 1.1;
  color: var(--text);
  margin-bottom: 1.5rem;
}

.hero-rule {
  width: 60px;
  height: 3px;
  background: var(--accent);
  margin-bottom: 1.5rem;
}

.hero-sub {
  font-size: 1.2rem;
  color: var(--text-dim);
  max-width: 540px;
  line-height: 1.7;
}

/* =========================================================
   FINDINGS (numbered principles/steps)
   ========================================================= */

.findings {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.finding {
  display: flex;
  gap: 2rem;
  align-items: flex-start;
}

.finding-number {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  color: var(--accent);
  opacity: 0.4;
  line-height: 1;
  flex-shrink: 0;
  min-width: 3rem;
}

.finding-content strong {
  display: block;
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 0.5rem;
  font-weight: 500;
  font-family: var(--font-body);
}

.finding-content p {
  color: var(--text-dim);
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

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

.findings + p {
  margin-top: 2rem;
}

/* When findings/workflow follow a closed .section-body as siblings,
   give them the same breathing room as nested usage */
.section-body + .findings,
.section-body + .workflow {
  margin-top: 2.5rem;
}

/* =========================================================
   STAT ROW (three-column)
   ========================================================= */

.stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin: 2rem 0;
}

.stat-col {
  background: var(--surface);
  padding: 2rem;
  border-left: 3px solid var(--accent);
}

.stat-col.accent-2 { border-left-color: var(--accent-2); }
.stat-col.accent-3 { border-left-color: var(--accent-3); }

.stat-value {
  font-family: var(--font-serif);
  font-size: 2rem;
  color: var(--text);
  margin-bottom: 0.5rem;
  line-height: 1.1;
}

.stat-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

/* =========================================================
   STAT CALLOUT (single prominent)
   ========================================================= */

.stat-callout {
  border-left: 3px solid var(--accent);
  padding: 1.5rem 2rem;
  background: var(--bg3);
  margin: 2rem 0;
}

.stat-big {
  font-family: var(--font-serif);
  font-size: 3rem;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.stat-desc {
  color: var(--text-dim);
  font-size: 1rem;
}

/* =========================================================
   CARDS (hub navigation)
   ========================================================= */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin: 2rem 0;
}

.card {
  background: var(--surface);
  padding: 2.5rem;
  text-decoration: none;
  transition: background 0.2s;
  display: block;
}

.card:hover {
  background: var(--bg3);
}

.card-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.card-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 400;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.card-desc {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-bottom: 0;
}

/* =========================================================
   ROADMAP (three columns)
   ========================================================= */

.roadmap {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin: 2rem 0;
}

.road-col {
  background: var(--surface);
  padding: 2rem;
  border-top: 3px solid var(--accent);
}

.road-col.accent-2 { border-top-color: var(--accent-2); }
.road-col.accent-3 { border-top-color: var(--accent-3); }

.road-phase {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.road-col.accent-2 .road-phase { color: var(--accent-2); }
.road-col.accent-3 .road-phase { color: var(--accent-3); }

.road-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.road-col p {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-bottom: 0.75rem;
}

.road-col ul {
  color: var(--text-dim);
  font-size: 0.9rem;
  padding-left: 1.25rem;
}

.road-col li { margin-bottom: 0.4rem; }

/* =========================================================
   CALLOUT / BLOCKQUOTE
   ========================================================= */

.callout {
  border-left: 3px solid var(--accent);
  padding: 1.25rem 1.75rem;
  background: var(--bg3);
  margin: 2rem 0;
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: var(--text);
  font-style: italic;
  list-style: none;
}

/* =========================================================
   TABLE
   ========================================================= */

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  font-size: 0.95rem;
}

th {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
  padding: 0.75rem 1rem;
  background: var(--bg3);
  color: var(--text-dim);
  border-bottom: 1px solid var(--border);
}

td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-dim);
  vertical-align: top;
}

td:first-child {
  color: var(--text);
  font-weight: 400;
}

tr:hover td {
  background: var(--bg3);
}

/* =========================================================
   WORKFLOW STEPS
   ========================================================= */

.workflow {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.workflow-step {
  display: flex;
  gap: 1.5rem;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
  align-items: flex-start;
}

.workflow-step:last-child { border-bottom: none; }

.step-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  letter-spacing: 0.1em;
  flex-shrink: 0;
  min-width: 2.5rem;
  padding-top: 0.25rem;
}

.step-body { flex: 1; }

.step-title {
  display: block;
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.step-body p {
  color: var(--text-dim);
  font-size: 0.97rem;
  margin-bottom: 0.75rem;
}

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

/* =========================================================
   PROMPT BLOCK
   ========================================================= */

.prompt-block {
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
  margin: 1.5rem 0;
}

.prompt-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.5rem 1rem;
  background: var(--bg3);
  color: var(--accent);
  border-bottom: 1px solid var(--border);
}

pre {
  padding: 1rem;
  background: var(--surface);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-dim);
  white-space: pre-wrap;
}

code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-dim);
  white-space: pre-wrap;
}


/* =========================================================
   IN-PAGE SECTION NAV (scroll-spy)
   ========================================================= */

.section-nav {
  position: sticky;
  top: 60px;
  background: color-mix(in srgb, var(--bg) 90%, transparent);
  backdrop-filter: blur(5px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
  padding: 0.75rem 0;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.section-nav::-webkit-scrollbar {
  display: none;
}

.section-nav-inner {
  min-width: 100%;
  width: max-content;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  gap: 1.25rem;
  align-items: center;
  justify-content: center;
}

.section-nav-link {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
}

.section-nav-link:hover,
.section-nav-link.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* =========================================================
   LOOP DIAGRAM
   ========================================================= */

.loop-diagram {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem;
  margin: 2rem 0;
  padding: 2rem;
  background: var(--bg3);
  border: 1px solid var(--border);
}

.loop-node {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0.5rem 0.85rem;
  border-radius: 2px;
  white-space: nowrap;
}

.loop-node.active {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-glow);
}

.loop-arrow {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  opacity: 0.5;
  padding: 0 0.1rem;
}

.loop-return {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  width: 100%;
  text-align: center;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px dashed var(--border);
}

/* =========================================================
   ARTICLE CONTENT (writing pages)
   ========================================================= */

.article-body h2 {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  color: var(--text);
  margin: 2.5rem 0 1rem;
  font-weight: 400;
}

.article-body h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  color: var(--text);
  margin: 2rem 0 0.75rem;
  font-weight: 400;
}

.article-body p {
  color: var(--text-dim);
  font-size: 1.05rem;
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.article-body .lead {
  font-size: 1.2rem;
  color: var(--text-dim);
  margin-bottom: 2rem;
}

/* =========================================================
   RELATED LINK
   ========================================================= */

.related-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--accent);
  padding-bottom: 0.15rem;
  transition: opacity 0.2s;
  margin-top: 1.5rem;
  display: inline-block;
}

.related-link:hover { opacity: 0.7; }

/* =========================================================
   FOOTER
   ========================================================= */

footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 3rem 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  align-items: center;
  text-align: center;
}

.footer-brand {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
}

.footer-links {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-links a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover { color: var(--accent); }

.footer-copy {
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* =========================================================
   PAGE NAVIGATION (lateral prev/next)
   ========================================================= */

.page-nav {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 2rem;
  border-top: 1px solid var(--border);
  padding: 2.5rem 0 0;
  margin-top: 1rem;
}

.page-nav-prev,
.page-nav-next {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  text-decoration: none;
  max-width: 280px;
}

.page-nav-next { text-align: right; margin-left: auto; }

.page-nav-direction {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.page-nav-label {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  color: var(--accent);
  transition: opacity 0.2s;
}

.page-nav-prev:hover .page-nav-label,
.page-nav-next:hover .page-nav-label {
  opacity: 0.7;
}

@media (max-width: 768px) {
  .page-nav { flex-direction: column; gap: 1.5rem; }
  .page-nav-next { text-align: left; margin-left: 0; }
}

/* =========================================================
   UTILITY
   ========================================================= */

.text-accent { color: var(--accent); }
.text-dim { color: var(--text-dim); }
.mono { font-family: var(--font-mono); }

.mt-2 { margin-top: 2rem; }
.mb-2 { margin-bottom: 2rem; }

/* =========================================================
   MOBILE RESPONSIVE
   ========================================================= */

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 2rem;
    border-bottom: 1px solid var(--border);
    gap: 1.5rem;
  }

  body.nav-open .nav-links {
    display: flex;
  }

  .nav-toggle {
    display: block;
    margin-left: auto;
  }

  .stat-row,
  .roadmap {
    grid-template-columns: 1fr;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: 2rem;
  }

  section {
    padding: 3rem 0;
  }

  .finding {
    gap: 1.25rem;
  }

  .finding-number {
    font-size: 2rem;
    min-width: 2.5rem;
  }

  .loop-diagram {
    padding: 1.25rem;
  }

  .section-nav-inner {
    gap: 0.875rem;
  }
}

@media (min-width: 769px) {
  .nav-toggle { display: none; }
}

/* page dateline (created/updated) */
.page-dateline{font-family:var(--font-mono,"DM Mono",monospace);font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;color:var(--text-muted,#888);margin:0 0 1.6rem;}