/* Faultline V3 — "Technical Exhibit" system. See DESIGN-MANUAL.md for rationale. */

/* ---------- Tokens ---------- */
:root {
  /* Surfaces */
  --surface-0: #F4F6F8;
  --surface-raised: #FFFFFF;
  --surface-alt: #EAEDF0;
  --surface-ink: #14181F;

  /* Lines */
  --line-hairline: #D2D8DE;
  --line-strong: #7A8391;

  /* Ink */
  --ink-strong: #14181F;
  --ink-body: #333B47;
  --ink-muted: #5B6472;
  --ink-on-dark: #F4F6F8;
  --ink-on-dark-muted: #9BA3B0;

  /* Signature + status */
  --fracture: #B3271E;
  --fracture-bright: #FF6B5E;
  --status-resolved: #0E7C6B;
  --status-investigating: #4B4FD1;

  /* Fonts */
  --font-display: Georgia, ui-serif, Cambria, "Times New Roman", Times, serif;
  --font-body: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Segoe UI Mono", "Roboto Mono", Menlo, Consolas, "Liberation Mono", monospace;

  /* Type scale (fluid) */
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: clamp(1.2rem, 1.1rem + 0.4vw, 1.4rem);
  --fs-xl: clamp(1.4rem, 1.2rem + 0.8vw, 1.85rem);
  --fs-2xl: clamp(1.75rem, 1.4rem + 1.4vw, 2.5rem);
  --fs-3xl: clamp(2.1rem, 1.6rem + 2vw, 3.25rem);
  --fs-4xl: clamp(2.6rem, 1.8rem + 3vw, 4.4rem);
  --fs-6xl: clamp(2.75rem, 1.9rem + 3.8vw, 5.25rem);

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4.5rem;
  --space-9: 6rem;
  --space-10: 8rem;

  --container-w: 1180px;
  --radius-sm: 3px;
  --radius-md: 6px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur-fast: 160ms;
  --dur-med: 520ms;
  --dur-slow: 700ms;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--surface-0);
  color: var(--ink-body);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; }
button { font: inherit; color: inherit; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, p, figure { margin: 0; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- Focus ---------- */
:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--fracture);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 100;
  background: var(--ink-strong);
  color: var(--ink-on-dark);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: top var(--dur-fast) var(--ease);
}
.skip-link:focus {
  top: var(--space-4);
}

/* ---------- Layout helpers ---------- */
.container {
  width: 100%;
  max-width: var(--container-w);
  margin-inline: auto;
  padding-inline: var(--space-5);
}
.section { padding-block: var(--space-9); }
.section--alt { background: var(--surface-alt); }
.section-head {
  max-width: 640px;
  margin-bottom: var(--space-7);
}
.section-head--center { margin-inline: auto; text-align: center; }

.kicker {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fracture);
  margin-bottom: var(--space-4);
}
.kicker::before {
  content: "";
  display: inline-block;
  width: 0.5em;
  height: 0.5em;
  background: var(--fracture);
  margin-right: 0.6em;
  vertical-align: middle;
  border-radius: 1px;
  transform: rotate(45deg);
}

h1, h2, h3 { font-family: var(--font-display); color: var(--ink-strong); font-weight: 600; letter-spacing: -0.015em; }
.h-display { font-size: var(--fs-6xl); line-height: 1.03; letter-spacing: -0.02em; }
.h-section { font-size: var(--fs-3xl); line-height: 1.1; }
.h-card { font-size: var(--fs-lg); line-height: 1.25; font-weight: 600; }
.lede { font-size: var(--fs-md); color: var(--ink-muted); line-height: 1.65; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  font-weight: 600;
  padding: 0.85rem 1.5rem;
  border-radius: var(--radius-sm);
  border: 1.5px solid transparent;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--fracture);
  color: #fff;
  box-shadow: 0 1px 0 rgba(20,24,31,0.06);
}
.btn-primary:hover { background: #9a2119; box-shadow: 0 6px 16px -6px rgba(179,39,30,0.55); }
.btn-secondary {
  background: transparent;
  color: var(--ink-strong);
  border-color: var(--line-strong);
}
.btn-secondary:hover { border-color: var(--fracture); color: var(--fracture); }
.btn-on-dark {
  background: var(--fracture-bright);
  color: var(--surface-ink);
}
.btn-on-dark:hover { background: #ff8378; box-shadow: 0 6px 20px -6px rgba(255,107,94,0.45); }
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1.5px solid transparent;
  transition: border-color var(--dur-fast) var(--ease), gap var(--dur-fast) var(--ease);
}
.link-arrow:hover { border-color: currentColor; gap: 0.6em; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(244,246,248,0.88);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line-hairline);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-4);
  gap: var(--space-5);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.35rem;
  color: var(--ink-strong);
  letter-spacing: -0.01em;
}
.brand-mark { width: 30px; height: 22px; flex-shrink: 0; }

.nav-primary { display: flex; align-items: center; }
.nav-links { display: flex; align-items: center; gap: var(--space-6); }
.nav-links a:not(.btn) {
  font-size: var(--fs-sm);
  font-weight: 600;
  text-decoration: none;
  color: var(--ink-body);
  position: relative;
  padding-block: var(--space-1);
}
.nav-links a:not(.btn)::after {
  content: "";
  position: absolute;
  left: 0; right: 100%;
  bottom: -2px;
  height: 2px;
  background: var(--fracture);
  transition: right var(--dur-fast) var(--ease);
}
.nav-links a:not(.btn):hover::after, .nav-links a:not(.btn):focus-visible::after { right: 0; }
.nav-links .nav-cta-item { margin-left: var(--space-2); }

.nav-toggle {
  display: none;
  background: none;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.6rem;
  cursor: pointer;
}
.nav-toggle svg { width: 20px; height: 20px; }
.nav-toggle .icon-close { display: none; }
.site-header[data-menu-open="true"] .nav-toggle .icon-open { display: none; }
.site-header[data-menu-open="true"] .nav-toggle .icon-close { display: block; }

@media (max-width: 860px) {
  .nav-links { display: none; }
  .nav-toggle { display: inline-flex; }
  .site-header[data-menu-open="true"] .nav-links {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--surface-raised);
    border-bottom: 1px solid var(--line-hairline);
    padding: var(--space-5);
    gap: var(--space-4);
  }
  .nav-links .nav-cta-item { margin-left: 0; }
}

/* ---------- Fracture crack divider ---------- */
.crack-divider {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}
.crack-divider path {
  fill: none;
  stroke: var(--fracture);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  vector-effect: non-scaling-stroke;
}
.crack-divider.is-drawing path {
  stroke-dasharray: 900;
  stroke-dashoffset: 900;
  transition: stroke-dashoffset var(--dur-slow) var(--ease);
}
.crack-divider.is-drawing.in-view path { stroke-dashoffset: 0; }

/* ---------- Hero ---------- */
.hero { padding-top: var(--space-8); padding-bottom: var(--space-8); position: relative; }
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  align-items: center;
}
.hero-copy { min-width: 0; }
.hero h1 { margin-bottom: var(--space-5); }
.hero .lede { max-width: 46ch; margin-bottom: var(--space-6); font-size: var(--fs-md); }

.pain-stat {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  background: var(--surface-raised);
  border: 1px solid var(--line-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  margin-bottom: var(--space-6);
  max-width: 30rem;
}
.pain-stat-item { flex: 1; min-width: 0; }
.pain-stat-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 0.35rem;
}
.pain-stat-value {
  font-family: var(--font-display);
  font-size: var(--fs-xl);
  color: var(--ink-strong);
  font-weight: 600;
  white-space: nowrap;
}
.pain-stat-value.is-after { color: var(--fracture); }
.pain-stat-crack { width: 34px; height: 28px; flex-shrink: 0; }
.pain-stat-crack path { fill: none; stroke: var(--fracture); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-5); }

/* ---------- Exhibit panel (Fig. 01 / Fig. 02) ---------- */
.exhibit { position: relative; min-width: 0; }
.exhibit-frame {
  position: relative;
  background: var(--surface-raised);
  border: 1px solid var(--line-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-6) var(--space-5) var(--space-5);
}
.exhibit-frame::before, .exhibit-frame::after,
.exhibit-tick-br::before, .exhibit-tick-bl::before {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border-color: var(--line-strong);
  border-style: solid;
  border-width: 0;
}
.exhibit-frame::before { top: -1px; left: -1px; border-top-width: 2px; border-left-width: 2px; }
.exhibit-frame::after { top: -1px; right: -1px; border-top-width: 2px; border-right-width: 2px; }
.exhibit-tick-bl, .exhibit-tick-br { position: absolute; bottom: -1px; width: 14px; height: 14px; }
.exhibit-tick-bl { left: -1px; }
.exhibit-tick-bl::before { border-bottom-width: 2px; border-left-width: 2px; bottom: 0; left: 0; }
.exhibit-tick-br { right: -1px; }
.exhibit-tick-br::before { border-bottom-width: 2px; border-right-width: 2px; bottom: 0; right: 0; }

.exhibit-caption {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--line-hairline);
}
.exhibit-caption strong { color: var(--ink-strong); font-weight: 700; }
.exhibit-caption .live-dot {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--status-resolved);
  margin-right: 0.5em;
}

/* Root-cause graph (Fig. 01) */
.graph-svg { width: 100%; height: auto; }
.graph-node-dot { stroke: var(--surface-raised); stroke-width: 2; }
.graph-node-dot.status-fracture { fill: var(--fracture); }
.graph-node-dot.status-investigating { fill: var(--status-investigating); }
.graph-node-dot.status-resolved { fill: var(--status-resolved); }
.graph-node-root { fill: var(--fracture); stroke: var(--surface-raised); stroke-width: 3; }
.graph-node-root-ring {
  fill: none;
  stroke: var(--fracture);
  stroke-opacity: 0.4;
  stroke-width: 2;
  transform-box: fill-box;
  transform-origin: center;
  animation: pulse-ring 2.4s ease-out infinite;
}
@keyframes pulse-ring {
  0% { transform: scale(0.8); opacity: 0.5; }
  75%, 100% { transform: scale(1.35); opacity: 0; }
}
.graph-edge { fill: none; }
.graph-edge.is-cause { stroke: var(--fracture); stroke-width: 3; }
.graph-edge.is-checking { stroke: var(--status-investigating); stroke-width: 1.75; }
.graph-edge.is-ruled-out { stroke: var(--line-strong); stroke-width: 1.5; stroke-dasharray: 4 4; }
.graph-label { font-family: var(--font-body); font-size: 13px; font-weight: 600; fill: var(--ink-strong); }
.graph-sublabel { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 0.02em; }
.graph-sublabel.status-fracture { fill: var(--fracture); }
.graph-sublabel.status-investigating { fill: var(--status-investigating); }
.graph-sublabel.status-resolved { fill: var(--status-resolved); }
.graph-root-label { font-family: var(--font-display); font-size: 16px; font-weight: 600; fill: var(--ink-strong); }

.graph-annotation {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px dashed var(--line-hairline);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--fracture);
}
.graph-annotation svg { width: 16px; height: 16px; flex-shrink: 0; margin-top: 0.15em; }

/* Incident timeline (Fig. 02) */
.timeline { position: relative; }
.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 5.5rem 1.1rem 1fr;
  gap: var(--space-4);
  padding-bottom: var(--space-5);
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-time {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-muted);
  padding-top: 0.15rem;
  text-align: right;
}
.timeline-rail { position: relative; display: flex; justify-content: center; }
.timeline-rail::before {
  content: "";
  position: absolute;
  top: 1.35rem;
  bottom: -1.25rem;
  width: 1.5px;
  background: var(--line-hairline);
}
.timeline-item:last-child .timeline-rail::before { display: none; }
.timeline-dot {
  position: relative;
  z-index: 1;
  width: 12px; height: 12px;
  border-radius: 50%;
  margin-top: 0.2rem;
  border: 2px solid var(--surface-raised);
  box-shadow: 0 0 0 1.5px var(--line-strong);
}
.timeline-dot.status-fracture { background: var(--fracture); box-shadow: 0 0 0 1.5px var(--fracture); }
.timeline-dot.status-investigating { background: var(--status-investigating); box-shadow: 0 0 0 1.5px var(--status-investigating); }
.timeline-dot.status-resolved { background: var(--status-resolved); box-shadow: 0 0 0 1.5px var(--status-resolved); }
.timeline-body { min-width: 0; }
.timeline-title { font-weight: 600; color: var(--ink-strong); font-size: 0.95rem; }
.timeline-detail { color: var(--ink-muted); font-size: 0.86rem; margin-top: 0.2rem; }
.timeline-item.is-final .timeline-title { color: var(--status-resolved); }

/* ---------- How it works steps ---------- */
.steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  margin-bottom: var(--space-8);
}
.step { display: flex; gap: var(--space-4); }
.step-index {
  font-family: var(--font-display);
  font-size: var(--fs-xl);
  color: var(--fracture);
  flex-shrink: 0;
  width: 2.2ch;
}
.step-title { margin-bottom: var(--space-2); }
.step-body { color: var(--ink-muted); font-size: 0.95rem; }

/* ---------- Results / stats ---------- */
.stats-lead {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-6);
  margin-bottom: var(--space-8);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--line-hairline);
}
.stats-lead-figure { text-align: center; }
.stats-lead-figure .pain-stat-value { font-size: var(--fs-2xl); }
.stats-lead-crack { width: 56px; height: 40px; }
.stats-lead-crack path { fill: none; stroke: var(--fracture); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr));
  gap: var(--space-7);
}
.stat-card { min-width: 0; }
.stat-number {
  font-family: var(--font-display);
  font-size: var(--fs-4xl);
  color: var(--ink-strong);
  line-height: 1;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}
.stat-label { color: var(--ink-muted); font-size: 0.92rem; max-width: 26ch; }

/* ---------- Features ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line-hairline);
  border: 1px solid var(--line-hairline);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.feature-card {
  background: var(--surface-raised);
  padding: var(--space-6);
  transition: background var(--dur-fast) var(--ease);
}
.feature-card:hover { background: var(--surface-alt); }
.feature-icon {
  width: 30px; height: 30px;
  margin-bottom: var(--space-4);
  color: var(--ink-strong);
  transition: color var(--dur-fast) var(--ease);
}
.feature-card:hover .feature-icon { color: var(--fracture); }
.feature-icon svg { width: 100%; height: 100%; }
.feature-card h3 { margin-bottom: var(--space-2); }
.feature-card p { color: var(--ink-muted); font-size: 0.92rem; }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--surface-ink);
  color: var(--ink-on-dark);
  padding-block: var(--space-9);
  position: relative;
  overflow: hidden;
}
.cta-inner { text-align: center; max-width: 44rem; margin-inline: auto; position: relative; }
.cta-band h2 { color: var(--ink-on-dark); margin-bottom: var(--space-4); }
.cta-band .lede { color: var(--ink-on-dark-muted); margin-bottom: var(--space-6); }
.cta-actions { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: var(--space-5); }
.cta-actions .link-arrow { color: var(--ink-on-dark); }
.cta-band-crack { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0.5; pointer-events: none; }
.cta-band-crack path { fill: none; stroke: var(--fracture-bright); stroke-width: 1.5; stroke-linecap: round; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--surface-alt);
  border-top: 1px solid var(--line-hairline);
  padding-block: var(--space-8) var(--space-6);
}
.footer-top {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--space-7);
  margin-bottom: var(--space-8);
}
.footer-brand .brand { margin-bottom: var(--space-3); }
.footer-tagline { color: var(--ink-muted); font-size: 0.92rem; max-width: 28ch; }
.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: var(--space-4);
  font-weight: 600;
}
.footer-col ul { display: flex; flex-direction: column; gap: var(--space-3); }
.footer-col a { text-decoration: none; color: var(--ink-body); font-size: 0.92rem; }
.footer-col a:hover { color: var(--fracture); }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-3);
  padding-top: var(--space-6);
  border-top: 1px solid var(--line-hairline);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-muted);
}

/* ---------- Scroll reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity var(--dur-med) var(--ease), transform var(--dur-med) var(--ease);
}
.reveal.in-view { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---------- Responsive ---------- */
@media (min-width: 640px) {
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 720px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-top { grid-template-columns: 1.4fr repeat(3, 1fr); }
}
@media (max-width: 719px) {
  .footer-top { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; margin-bottom: var(--space-4); }
}
@media (min-width: 960px) {
  .hero-grid { grid-template-columns: 1.05fr 0.95fr; }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .stat-grid { grid-template-columns: repeat(4, 1fr); }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .timeline-item { grid-template-columns: 6rem 1.1rem 1fr; }
}
@media (max-width: 480px) {
  .pain-stat { flex-direction: column; align-items: stretch; gap: var(--space-4); }
  .pain-stat-crack { transform: rotate(90deg); margin-inline: auto; }
  .timeline-item { grid-template-columns: 4rem 1rem 1fr; gap: var(--space-3); }
  .timeline-time { font-size: 0.7rem; }
}