/* ========================================================================
   ORBITAL // The Case for Space-Based AI Compute
   Aesthetic: technical sci-fi / Akira / SpaceX-ops console
   ======================================================================== */

:root {
  /* Type scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);
  --text-hero: clamp(2.5rem, 0.5rem + 5vw, 5.5rem);

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Color — dark-mode native, Akira/console */
  --color-bg: #050810;
  --color-bg-2: #07101c;
  --color-surface: #0b1626;
  --color-surface-2: #11203a;
  --color-divider: #1d3252;
  --color-border: #1f3c66;

  --color-text: #d9e4f1;
  --color-text-muted: #7a8aa3;
  --color-text-faint: #455772;

  --color-primary: #00d9ff; /* cyan — orbital glow */
  --color-primary-soft: #16384a;
  --color-accent: #ff6b1a; /* orange — Starship plume */
  --color-accent-soft: #3a1a0a;
  --color-warn: #ffd23f; /* gold — caution telemetry */
  --color-success: #4ade80;
  --color-danger: #ff3a7f;

  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.875rem;

  --transition: 200ms cubic-bezier(0.16, 1, 0.3, 1);

  --font-body: "Space Grotesk", -apple-system, system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, Menlo, monospace;

  --content-wide: 1200px;
  --content-default: 980px;
}

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

html {
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-16);
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  background-image:
    radial-gradient(ellipse at 20% 0%, rgba(0, 217, 255, 0.06), transparent 60%),
    radial-gradient(ellipse at 80% 30%, rgba(255, 107, 26, 0.04), transparent 60%);
  background-attachment: fixed;
  overflow-x: hidden;
  position: relative;
}

img,
canvas,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: #6ce8ff;
}

::selection {
  background: var(--color-primary);
  color: var(--color-bg);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

button {
  cursor: pointer;
  background: none;
  border: none;
  color: inherit;
  font: inherit;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-body);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.05;
  text-wrap: balance;
}

p {
  text-wrap: pretty;
  max-width: 72ch;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- starfield ---------- */
#starfield {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
  opacity: 0.6;
}

/* ---------- topbar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-3) clamp(var(--space-4), 4vw, var(--space-10));
  background: rgba(5, 8, 16, 0.7);
  backdrop-filter: blur(12px) saturate(140%);
  border-bottom: 1px solid var(--color-divider);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-primary);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}
.brand-mark {
  color: var(--color-primary);
  filter: drop-shadow(0 0 8px rgba(0, 217, 255, 0.4));
  animation: spin 24s linear infinite;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}
.brand-text {
  font-size: var(--text-sm);
  color: var(--color-text);
}
.brand-sub {
  color: var(--color-text-faint);
  margin-left: var(--space-1);
}

.topbar nav {
  display: flex;
  gap: var(--space-5);
}
.topbar nav a {
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.topbar nav a:hover {
  color: var(--color-primary);
}

.status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
}
.status .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-success);
  box-shadow: 0 0 8px var(--color-success);
  animation: pulse 1.8s ease-in-out infinite;
}
@keyframes pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.35;
  }
}

@media (max-width: 720px) {
  .topbar nav,
  .status .status-text {
    display: none;
  }
}

/* ---------- hero ---------- */
.hero {
  position: relative;
  min-height: 92dvh;
  padding: clamp(var(--space-10), 8vw, var(--space-24))
    clamp(var(--space-4), 4vw, var(--space-10));
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: var(--space-12);
  align-items: center;
  overflow: hidden;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(31, 60, 102, 0.18) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 60, 102, 0.18) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 30% 50%, #000 30%, transparent 75%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.eyebrow {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}
.tag {
  padding: 4px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-primary);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  background: rgba(0, 217, 255, 0.05);
}
.tag-warn {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background: rgba(255, 107, 26, 0.08);
}
.tag-faint {
  color: var(--color-text-faint);
  padding: 4px 0;
  letter-spacing: 0.12em;
}

.hero-title {
  font-size: var(--text-hero);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-6);
}
.hero-title .line {
  display: block;
}
.hero-title .accent {
  color: var(--color-primary);
  font-style: italic;
  font-weight: 500;
}

.hero-lede {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  max-width: 60ch;
}
.hero-lede em {
  color: var(--color-text);
  font-style: normal;
  font-weight: 500;
  background: linear-gradient(180deg, transparent 60%, rgba(0, 217, 255, 0.18) 60%);
  padding: 0 2px;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-12);
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-radius: var(--radius-sm);
  transition:
    transform var(--transition),
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}
.btn.primary {
  background: var(--color-primary);
  color: var(--color-bg);
  box-shadow: 0 0 24px rgba(0, 217, 255, 0.3);
}
.btn.primary:hover {
  background: #6ce8ff;
  transform: translateY(-1px);
  color: var(--color-bg);
}
.btn.ghost {
  border: 1px solid var(--color-border);
  color: var(--color-text);
}
.btn.ghost:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-4);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
}
.stat {
  font-family: var(--font-mono);
}
.stat-num {
  font-size: clamp(1.5rem, 2.2vw, 2.25rem);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
  line-height: 1;
}
.stat-suffix {
  font-size: 0.55em;
  color: var(--color-text-muted);
  font-weight: 500;
  margin-left: 2px;
}
.stat-unit {
  font-size: var(--text-xs);
  color: var(--color-primary);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-top: var(--space-1);
}
.stat-label {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

.hero-orbit {
  position: relative;
  z-index: 2;
  aspect-ratio: 1 / 1;
  max-width: 560px;
  margin: 0 auto;
  border: 1px solid var(--color-divider);
  border-radius: 50%;
  padding: var(--space-3);
  background: radial-gradient(circle, rgba(0, 217, 255, 0.04), transparent 70%);
}
#orbit-canvas {
  width: 100%;
  height: 100%;
}
.orbit-caption {
  position: absolute;
  bottom: -28px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  white-space: nowrap;
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }
  .hero-orbit {
    max-width: 360px;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ---------- generic section ---------- */
.section {
  position: relative;
  padding: clamp(var(--space-16), 10vw, var(--space-32))
    clamp(var(--space-4), 4vw, var(--space-10));
  max-width: var(--content-wide);
  margin: 0 auto;
}

.section-header {
  margin-bottom: var(--space-12);
  max-width: 720px;
}
.section-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
  padding: 3px 10px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
  background: rgba(0, 217, 255, 0.06);
}
.section h2 {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-3);
}
.section-sub {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  max-width: 56ch;
}

/* ---------- thesis (critics vs reality) ---------- */
.diff-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
}
.diff-card {
  position: relative;
  padding: var(--space-8);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.diff-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
}
.diff-bad::before {
  background: linear-gradient(90deg, var(--color-danger), transparent);
}
.diff-good::before {
  background: linear-gradient(90deg, var(--color-primary), transparent);
}
.diff-card header {
  margin-bottom: var(--space-5);
}
.diff-label {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}
.diff-bad .diff-label {
  color: var(--color-danger);
}
.diff-good .diff-label {
  color: var(--color-primary);
}
.diff-card h3 {
  font-size: var(--text-lg);
  font-weight: 600;
}
.diff-bad h3 {
  color: #ffa9c1;
}
.diff-good h3 {
  color: #b5f0ff;
}
.diff-card ul {
  list-style: none;
  display: grid;
  gap: var(--space-3);
}
.diff-card li {
  position: relative;
  padding-left: var(--space-6);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.diff-bad li::before {
  content: "✕";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--color-danger);
  font-family: var(--font-mono);
}
.diff-good li::before {
  content: "→";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--color-primary);
  font-family: var(--font-mono);
}
.diff-good li strong {
  color: var(--color-text);
  font-weight: 600;
}
.diff-card footer {
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: 1px dashed var(--color-divider);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.05em;
}

@media (max-width: 800px) {
  .diff-grid {
    grid-template-columns: 1fr;
  }
}

/* ---------- math / calculator ---------- */
.section-math {
  background:
    linear-gradient(180deg, transparent, rgba(0, 217, 255, 0.02), transparent),
    radial-gradient(ellipse at center, rgba(0, 217, 255, 0.04), transparent 60%);
  border-radius: var(--radius-lg);
}

.calc {
  display: grid;
  gap: var(--space-8);
}
.calc-controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-5);
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
}
.control label {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}
.control label output {
  color: var(--color-primary);
  font-weight: 700;
}
.control-hint {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-2);
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: var(--color-divider);
  border-radius: 2px;
  outline: none;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 12px rgba(0, 217, 255, 0.6);
  cursor: pointer;
  transition: transform var(--transition);
}
input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}
input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 2px solid var(--color-bg);
  cursor: pointer;
}

.calc-output {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-5);
}
.card {
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}
.earth-card {
  border-color: rgba(255, 107, 26, 0.3);
}
.earth-card::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 80px;
  height: 80px;
  background: radial-gradient(circle, rgba(255, 107, 26, 0.18), transparent);
  pointer-events: none;
}
.orbit-card {
  border-color: rgba(0, 217, 255, 0.3);
}
.orbit-card::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 80px;
  height: 80px;
  background: radial-gradient(circle, rgba(0, 217, 255, 0.2), transparent);
  pointer-events: none;
}
.crossover {
  background: linear-gradient(160deg, var(--color-surface), var(--color-surface-2));
  border-color: var(--color-primary);
  text-align: center;
}

.card-tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}
.earth-card .card-tag {
  color: var(--color-accent);
}
.orbit-card .card-tag {
  color: var(--color-primary);
}
.crossover .card-tag {
  color: var(--color-warn);
}

.card-main {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-text);
  line-height: 1;
}
.card-unit {
  font-size: 0.5em;
  color: var(--color-text-muted);
  margin-left: 4px;
  font-weight: 500;
}
.card-sub {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-2);
}
.card-stats {
  list-style: none;
  margin-top: var(--space-5);
  display: grid;
  gap: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}
.card-stats li {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px dashed var(--color-divider);
  color: var(--color-text-muted);
}
.card-stats li span {
  color: var(--color-text);
  text-align: right;
}
.card-stats li em {
  color: var(--color-text-faint);
  font-style: normal;
}

.verdict {
  display: inline-block;
  margin: var(--space-2) 0 var(--space-3);
  padding: 6px 14px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  background: var(--color-primary);
  color: var(--color-bg);
  border-radius: var(--radius-sm);
  font-weight: 700;
}
.bar {
  height: 6px;
  background: var(--color-divider);
  border-radius: 3px;
  overflow: hidden;
  margin-top: var(--space-4);
}
.bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-warn));
  transition: width 400ms cubic-bezier(0.16, 1, 0.3, 1);
  width: 0%;
}

.calc-foot {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  max-width: 80ch;
}

/* ---------- TCO chart ---------- */
.chart-wrap {
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}
.chart-wrap::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 0%, rgba(0, 217, 255, 0.05), transparent 60%),
    radial-gradient(ellipse at 90% 100%, rgba(255, 107, 26, 0.05), transparent 60%);
  pointer-events: none;
}
.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}
.chart-tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}
.chart-title {
  font-size: var(--text-lg);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.chart-legend {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}
.chart-legend .lg {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}
.chart-legend .lg i {
  width: 18px;
  height: 3px;
  border-radius: 2px;
  display: inline-block;
}
.chart-legend .lg-earth i {
  background: var(--color-accent);
}
.chart-legend .lg-orbit i {
  background: var(--color-primary);
}
.chart-legend .lg-cross i {
  background: var(--color-warn);
  height: 12px;
  width: 2px;
  margin: 0 8px;
}
#tco-chart {
  width: 100%;
  height: 360px;
  display: block;
  position: relative;
  z-index: 1;
}
.chart-caption {
  margin-top: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
  position: relative;
  z-index: 1;
}
.chart-caption strong {
  color: var(--color-warn);
  font-weight: 700;
}

@media (max-width: 600px) {
  #tco-chart {
    height: 280px;
  }
  .chart-header {
    align-items: flex-start;
  }
}

@media (max-width: 800px) {
  .calc-output {
    grid-template-columns: 1fr;
  }
}

/* ---------- calc reordering: chart on top, cards below ---------- */
.calc-chart-first {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}
.calc-chart-first .chart-wrap-top {
  order: 1;
}
.calc-chart-first .calc-controls {
  order: 2;
}
.calc-chart-first .calc-output-below {
  order: 3;
}
.calc-chart-first .calc-foot {
  order: 4;
}

/* ---------- launch cost collapse infographic ---------- */
.section-collapse {
  /* full-bleed feel */
}
.collapse-wrap {
  position: relative;
  padding: var(--space-7) var(--space-6) var(--space-6);
  background:
    linear-gradient(180deg, rgba(0, 217, 255, 0.04), rgba(255, 107, 26, 0.04)),
    var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.collapse-wrap::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 5% 0%, rgba(255, 107, 26, 0.12), transparent 50%),
    radial-gradient(ellipse at 95% 100%, rgba(0, 217, 255, 0.12), transparent 50%);
  pointer-events: none;
}
.collapse-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-5);
  position: relative;
  z-index: 1;
}
.collapse-tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-primary);
  text-transform: uppercase;
}
.collapse-delta {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--color-warn);
  padding: 4px 10px;
  border: 1px solid rgba(255, 210, 63, 0.4);
  border-radius: var(--radius-sm);
  background: rgba(255, 210, 63, 0.06);
}
#collapse-chart {
  width: 100%;
  height: 420px;
  display: block;
  position: relative;
  z-index: 1;
}
.collapse-foot {
  margin-top: var(--space-5);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.04em;
  max-width: 90ch;
  position: relative;
  z-index: 1;
}
@media (max-width: 900px) {
  #collapse-chart {
    height: 340px;
  }
}
@media (max-width: 600px) {
  #collapse-chart {
    height: 280px;
  }
  .collapse-wrap {
    padding: var(--space-5) var(--space-4);
  }
}

/* ---------- receipts ---------- */
.receipts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-5);
}
.receipt {
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  transition:
    border-color var(--transition),
    transform var(--transition);
}
.receipt:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}
.receipt-num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 2.5vw, 2.25rem);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--space-2);
  letter-spacing: -0.02em;
}
.receipt-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}
.receipt p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}
.receipt-src {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* ---------- timeline ---------- */
.section-timeline {
  max-width: 1080px;
}
.timeline {
  list-style: none;
  position: relative;
  padding-left: var(--space-10);
}
.timeline::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(
    180deg,
    var(--color-primary) 0%,
    var(--color-accent) 60%,
    var(--color-warn) 100%
  );
  opacity: 0.5;
}
.t-item {
  position: relative;
  padding: 0 0 var(--space-10) 0;
}
.t-item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid var(--color-primary);
  box-shadow: 0 0 0 4px rgba(0, 217, 255, 0.12);
}
.t-item[data-phase="lunar-bootstrap"]::before,
.t-item[data-phase="lunar-scale"]::before {
  border-color: var(--color-warn);
  box-shadow: 0 0 0 4px rgba(255, 210, 63, 0.12);
}
.t-item[data-phase="terawatt"]::before,
.t-item[data-phase="scale"]::before {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 4px rgba(255, 107, 26, 0.12);
}
.t-item[data-phase="dominance"]::before,
.t-item[data-phase="frontier"]::before,
.t-item[data-phase="kii"]::before {
  background: var(--color-primary);
  box-shadow:
    0 0 0 4px rgba(0, 217, 255, 0.2),
    0 0 16px var(--color-primary);
}
.t-year {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.15em;
  color: var(--color-primary);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: var(--space-2);
}
.t-body h3 {
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
}
.t-body p {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  max-width: 64ch;
}
.t-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}
.t-tags span {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: lowercase;
  padding: 2px 8px;
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
}

/* ---------- faq ---------- */
.faq {
  display: grid;
  gap: var(--space-3);
}
.faq details {
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  overflow: hidden;
  transition: border-color var(--transition);
}
.faq details:hover {
  border-color: var(--color-primary);
}
.faq details[open] {
  border-color: var(--color-primary);
}
.faq summary {
  list-style: none;
  cursor: pointer;
  padding: var(--space-5) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}
.faq summary::-webkit-details-marker {
  display: none;
}
.faq .q {
  font-weight: 500;
  color: var(--color-text);
  font-size: var(--text-base);
}
.faq .chev {
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  color: var(--color-primary);
  transition: transform var(--transition);
}
.faq details[open] .chev {
  transform: rotate(45deg);
}
.faq .a {
  padding: 0 var(--space-6) var(--space-5);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.faq .a em {
  color: var(--color-primary);
  font-style: italic;
}

/* ---------- long-form FAQ answer ---------- */
.faq .a-long {
  padding: var(--space-2) var(--space-6) var(--space-6);
  max-width: 78ch;
  color: var(--color-text);
  font-size: var(--text-sm);
  line-height: 1.65;
}
.faq .a-long p {
  margin: 0 0 var(--space-4);
}
.faq .a-long h4 {
  margin: var(--space-6) 0 var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  border-left: 2px solid var(--color-primary);
  padding-left: var(--space-3);
}
.faq .a-long h4:first-of-type,
.faq .a-long > h4:first-child {
  margin-top: var(--space-3);
}
.faq .a-long em {
  color: var(--color-primary);
  font-style: italic;
}
.faq .a-long strong {
  color: var(--color-text);
  font-weight: 700;
}
.faq .a-mini-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin: var(--space-5) 0 var(--space-2) !important;
}
.faq .a-list {
  margin: 0 0 var(--space-4);
  padding-left: var(--space-5);
  list-style: none;
}
.faq .a-list li {
  position: relative;
  padding-left: var(--space-4);
  margin-bottom: var(--space-2);
  color: var(--color-text-muted);
}
.faq .a-list li::before {
  content: "›";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-weight: 700;
}
.faq .a-list.a-ordered {
  counter-reset: pb;
}
.faq .a-list.a-ordered li::before {
  counter-increment: pb;
  content: counter(pb, decimal-leading-zero);
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
}
.faq .a-list.a-ordered li {
  padding-left: var(--space-6);
}
.faq .a-callout {
  margin: var(--space-5) 0 !important;
  padding: var(--space-4) var(--space-5);
  border-left: 3px solid var(--color-primary);
  background: linear-gradient(
    90deg,
    rgba(0, 217, 255, 0.08),
    rgba(0, 217, 255, 0.0)
  );
  color: var(--color-text);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.faq .a-math {
  margin: var(--space-4) 0 var(--space-5);
  padding: var(--space-5);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-md);
  background: rgba(0, 7, 13, 0.5);
}
.faq .a-math p {
  margin: 0 0 var(--space-2);
}
.faq .a-math ul {
  list-style: none;
  padding-left: 0;
  margin: var(--space-2) 0 var(--space-3);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-1) var(--space-4);
}
.faq .a-math ul li {
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}
.faq .a-math code {
  background: rgba(0, 217, 255, 0.12);
  color: var(--color-primary);
  padding: 1px 6px;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 11px;
  margin-right: 4px;
}
.faq .a-eq {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-warn);
  background: rgba(255, 210, 63, 0.05);
  border-left: 2px solid var(--color-warn);
  padding: var(--space-2) var(--space-3);
  margin: var(--space-2) 0 !important;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  letter-spacing: 0.02em;
}
.faq .a-eq strong {
  color: var(--color-warn);
  font-weight: 700;
}
@media (max-width: 700px) {
  .faq .a-math ul {
    grid-template-columns: 1fr;
  }
  .faq .a-long {
    padding: var(--space-2) var(--space-5) var(--space-5);
  }
}

/* ---------- closer ---------- */
.section-closer {
  padding-bottom: var(--space-32);
}
.closer-card {
  padding: clamp(var(--space-8), 6vw, var(--space-16));
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(0, 217, 255, 0.06), rgba(255, 107, 26, 0.04)),
    var(--color-surface);
  position: relative;
  overflow: hidden;
}
.closer-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 80% 20%, rgba(0, 217, 255, 0.18), transparent 50%);
  pointer-events: none;
}
.closer-eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}
.closer-card h2 {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-5);
}
.closer-card .strike {
  text-decoration: line-through;
  text-decoration-color: var(--color-danger);
  text-decoration-thickness: 3px;
  color: var(--color-text-faint);
}
.closer-card .accent {
  color: var(--color-primary);
  font-style: italic;
}
.closer-card p {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  max-width: 72ch;
}
.signoff {
  margin-top: var(--space-10);
  padding-top: var(--space-6);
  border-top: 1px dashed var(--color-divider);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-4);
  font-family: var(--font-mono);
}
.sig {
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.see-you {
  color: var(--color-primary);
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: 0.15em;
}

/* ---------- footer ---------- */
.footer {
  border-top: 1px solid var(--color-divider);
  padding: var(--space-16) clamp(var(--space-4), 4vw, var(--space-10)) var(--space-8);
  background: var(--color-bg-2);
  position: relative;
  z-index: 1;
}
.footer-grid {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: var(--space-10);
}
.footer-brand {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.2em;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}
.footer-small {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  max-width: 36ch;
}
.footer-head {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}
.footer ul {
  list-style: none;
  display: grid;
  gap: var(--space-2);
}
.footer ul li {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.footer ul.spec li {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.footer-rule {
  max-width: var(--content-wide);
  margin: var(--space-10) auto var(--space-4);
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent,
    var(--color-divider) 20%,
    var(--color-divider) 80%,
    transparent
  );
}
.footer-meta {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-text-faint);
  text-transform: uppercase;
}

@media (max-width: 800px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
}