/* ==========================================================================
   BLACK WIDOW · Website V5 · Production CSS
   Evidence-driven layout · Phase I Research Validation Proposal
   ========================================================================== */

/* ---------- 1. Design tokens ---------- */

:root {
  /* Colour system */
  --v5-bg: #0a0e14;
  --v5-bg-elev: #10151d;
  --v5-bg-panel: #141a24;
  --v5-fg: #ffffff;
  --v5-fg-muted: #d2d8e2;
  --v5-fg-dim: #a3adbc;
  --v5-border: rgba(255, 255, 255, 0.08);
  --v5-border-strong: rgba(255, 255, 255, 0.16);
  --v5-accent: #c9ff3a;
  --v5-accent-fg: #0a0e14;
  --v5-brief: #f97316;
  --v5-brief-hover: #fb923c;
  --v5-brief-fg: #0a0e14;
  --v5-danger: #ff5c5c;
  --v5-status-done: #4ade80;
  --v5-status-active: #facc15;
  --v5-status-planned: #6a7386;

  /* Typography */
  --v5-font-body: "Manrope", system-ui, -apple-system, "Segoe UI", sans-serif;
  --v5-font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --v5-text-xs: 0.75rem;
  --v5-text-sm: 0.875rem;
  --v5-text-base: 1rem;
  --v5-text-lg: 1.125rem;
  --v5-text-xl: 1.35rem;
  --v5-text-2xl: 1.75rem;
  --v5-text-3xl: 2.25rem;
  --v5-text-4xl: 3rem;
  --v5-text-5xl: 4rem;
  --v5-lh-tight: 1.15;
  --v5-lh-body: 1.55;

  /* Spacing */
  --v5-space-2xs: 0.25rem;
  --v5-space-xs: 0.5rem;
  --v5-space-sm: 0.75rem;
  --v5-space-md: 1rem;
  --v5-space-lg: 1.5rem;
  --v5-space-xl: 2.5rem;
  --v5-space-2xl: 4rem;
  --v5-space-3xl: 6rem;

  /* Layout */
  --v5-container: 1200px;
  --v5-container-narrow: 880px;
  --v5-radius-sm: 4px;
  --v5-radius-md: 8px;
  --v5-radius-lg: 12px;

  /* Motion */
  --v5-ease: cubic-bezier(0.4, 0, 0.2, 1);
  --v5-transition-fast: 120ms var(--v5-ease);
  --v5-transition: 200ms var(--v5-ease);
}

/* ---------- 2. Base reset ---------- */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  margin: 0;
  background: var(--v5-bg);
  color: var(--v5-fg);
  font-family: var(--v5-font-body);
  font-size: var(--v5-text-base);
  line-height: var(--v5-lh-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img,
picture,
video {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--v5-transition-fast);
}

a:hover {
  color: var(--v5-accent);
}

button {
  font: inherit;
  cursor: pointer;
  background: transparent;
  color: inherit;
  border: 0;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 800;
  line-height: var(--v5-lh-tight);
  letter-spacing: -0.01em;
}

p {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

figure {
  margin: 0;
}

:focus-visible {
  outline: 2px solid var(--v5-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

::selection {
  background: var(--v5-accent);
  color: var(--v5-accent-fg);
}

/* ---------- 3. Layout helpers ---------- */

.v5-container {
  max-width: var(--v5-container);
  padding-inline: clamp(1rem, 4vw, 2rem);
  margin-inline: auto;
}

.v5-container--narrow {
  max-width: var(--v5-container-narrow);
}

.v5-section {
  padding-block: var(--v5-space-3xl);
  border-top: 1px solid var(--v5-border);
}

.v5-section:first-of-type {
  border-top: 0;
}

.v5-section--dark {
  background: var(--v5-bg-elev);
}

.v5-eyebrow {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--v5-fg-muted);
  margin-bottom: var(--v5-space-md);
}

.v5-heading {
  font-size: clamp(var(--v5-text-2xl), 4vw, var(--v5-text-4xl));
  margin-bottom: var(--v5-space-lg);
}

.v5-lead {
  font-size: var(--v5-text-lg);
  color: var(--v5-fg-muted);
  max-width: 60ch;
  margin-bottom: var(--v5-space-xl);
}

.v5-visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Content markers — visible during content-integration phase */
.v5-marker {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  color: var(--v5-danger);
  background: rgba(255, 92, 92, 0.08);
  border: 1px dashed rgba(255, 92, 92, 0.4);
  border-radius: var(--v5-radius-sm);
  letter-spacing: 0.06em;
}

.v5-marker--block {
  display: block;
  padding: var(--v5-space-md);
  margin-block: var(--v5-space-sm);
}

/* Photo slot placeholder */
.v5-photo-slot {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 16 / 9;
  background: repeating-linear-gradient(
      45deg,
      rgba(255, 255, 255, 0.02) 0 12px,
      rgba(255, 255, 255, 0.04) 12px 24px
    ),
    var(--v5-bg-panel);
  border: 1px dashed var(--v5-border-strong);
  border-radius: var(--v5-radius-md);
  color: var(--v5-fg-muted);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-sm);
  text-align: center;
  padding: var(--v5-space-lg);
}

.v5-photo-slot[data-aspect="3/4"] {
  aspect-ratio: 3 / 4;
}

.v5-photo-slot[data-aspect="4/3"] {
  aspect-ratio: 4 / 3;
}

.v5-photo-slot[data-aspect="1/1"] {
  aspect-ratio: 1 / 1;
}

.v5-photo-slot::before {
  content: attr(data-photo);
  display: block;
  color: var(--v5-fg-muted);
  letter-spacing: 0.08em;
}

/* Real photograph state — placeholder chrome removed, image fills slot. */
.v5-photo-slot.has-media {
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  padding: 0;
  overflow: hidden;
}

.v5-photo-slot.has-media::before {
  display: none;
}

.v5-photo-slot img,
.v5-photo-slot picture,
.v5-photo-slot picture img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ---------- 4. Buttons ---------- */

.v5-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--v5-space-xs);
  padding: 0.85rem 1.35rem;
  font-family: var(--v5-font-body);
  font-size: var(--v5-text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
  border-radius: var(--v5-radius-md);
  border: 1px solid transparent;
  transition: background var(--v5-transition-fast),
    color var(--v5-transition-fast), border-color var(--v5-transition-fast);
  white-space: nowrap;
}

.v5-btn--primary {
  background: var(--v5-accent);
  color: var(--v5-accent-fg);
}

.v5-btn--primary:hover {
  background: #d9ff5a;
  color: var(--v5-accent-fg);
}

.v5-btn--brief {
  background: var(--v5-brief);
  color: var(--v5-brief-fg);
  border-color: transparent;
}

.v5-btn--brief:hover {
  background: var(--v5-brief-hover);
  color: var(--v5-brief-fg);
}

.v5-btn--budget {
  background: var(--v5-accent);
  color: var(--v5-accent-fg);
  border-color: transparent;
}

.v5-btn--budget:hover {
  background: #d9ff5a;
  color: var(--v5-accent-fg);
}

.v5-btn--ghost {
  background: transparent;
  color: var(--v5-fg);
  border-color: var(--v5-border-strong);
}

.v5-btn--ghost:hover {
  border-color: var(--v5-accent);
  color: var(--v5-accent);
}

.v5-btn--sm {
  padding: 0.55rem 0.9rem;
  font-size: var(--v5-text-xs);
}

/* ---------- 4b. Identity strip (top of document) ----------
   Institutional single-line header. Not sticky — scrolls away,
   sticky primary nav takes over. Reads as preprint / lab letterhead.
*/

.v5-identity-strip {
  background: #05080c;
  border-bottom: 1px solid var(--v5-border);
  font-family: var(--v5-font-mono);
  font-size: 0.6875rem;
  line-height: 1.4;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--v5-fg-muted);
}

.v5-identity-strip__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  column-gap: 0.75rem;
  row-gap: 0.15rem;
  padding-block: 0.55rem;
  text-align: center;
}

.v5-identity-strip__mark {
  width: 18px;
  height: 18px;
  display: inline-block;
  vertical-align: middle;
  object-fit: contain;
  margin-right: 0.15rem;
  flex-shrink: 0;
  opacity: 0.92;
}

.v5-identity-strip__name {
  color: var(--v5-fg);
  font-weight: 700;
  letter-spacing: 0.18em;
}

.v5-identity-strip__sep {
  color: var(--v5-fg-dim);
  opacity: 0.45;
}

.v5-identity-strip time {
  font-variant-numeric: tabular-nums;
}

@media (max-width: 720px) {
  .v5-identity-strip {
    font-size: 0.625rem;
    letter-spacing: 0.1em;
  }

  .v5-identity-strip__inner {
    column-gap: 0.5rem;
  }
}

/* ---------- 5. Header · primary nav ---------- */

.v5-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(10, 14, 20, 0.85);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid var(--v5-border);
}

.v5-header-inner {
  display: flex;
  align-items: center;
  gap: var(--v5-space-lg);
  padding-block: var(--v5-space-md);
}

.v5-brand {
  display: flex;
  align-items: baseline;
  gap: 0.35rem;
  font-family: var(--v5-font-mono);
  font-weight: 700;
  font-size: var(--v5-text-base);
  letter-spacing: 0.14em;
  color: var(--v5-fg);
}

.v5-brand strong {
  color: var(--v5-accent);
  font-weight: 700;
}

.v5-nav {
  margin-inline-start: auto;
}

.v5-nav-list {
  display: flex;
  align-items: center;
  gap: var(--v5-space-lg);
}

.v5-nav-list a {
  font-size: var(--v5-text-sm);
  color: var(--v5-fg-muted);
  padding-block: var(--v5-space-xs);
}

.v5-nav-list a:hover,
.v5-nav-list a[aria-current="page"] {
  color: var(--v5-fg);
}

.v5-nav-list a.v5-nav-research-center {
  color: var(--v5-accent);
  font-family: var(--v5-font-mono);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-size: var(--v5-text-xs);
}

.v5-nav-list a.v5-nav-research-center:hover {
  color: var(--v5-fg);
}

.v5-tech-card__link {
  margin-top: var(--v5-space-md);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.v5-tech-card__link a {
  color: var(--v5-accent);
}

.v5-tech-card__link a:hover {
  color: var(--v5-fg);
}

.v5-lang {
  display: inline-flex;
  gap: var(--v5-space-xs);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.08em;
  color: var(--v5-fg-muted);
}

.v5-lang a.is-active {
  color: var(--v5-fg);
}

.v5-nav-toggle {
  display: none;
  padding: var(--v5-space-xs) var(--v5-space-md);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.08em;
  border: 1px solid var(--v5-border-strong);
  border-radius: var(--v5-radius-sm);
  color: var(--v5-fg);
}

/* ---------- 6. SECTION 1 · Hero (problem-framed) ---------- */

.v5-hero {
  padding: 0;
  background: var(--v5-bg);
  border-top: 0;
}

.v5-hero-stage {
  position: relative;
  width: 100%;
  overflow: hidden;
}

.v5-hero-stage::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(
    90deg,
    rgba(8, 11, 16, 0.96) 0%,
    rgba(8, 11, 16, 0.88) 34%,
    rgba(8, 11, 16, 0.52) 46%,
    rgba(8, 11, 16, 0.12) 58%,
    transparent 72%
  );
}

.v5-hero-visual {
  width: 100%;
  margin: 0;
}

.v5-hero-visual .v5-photo-slot {
  aspect-ratio: 1024 / 571;
  border-radius: 0;
  border: 0;
}

.v5-hero-visual .v5-photo-slot img {
  object-position: 18% center;
}

.v5-hero-overlay {
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
}

.v5-hero-copy {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 42%;
  max-width: 42%;
  padding: 4.5% 3% 4% 3.5%;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.85rem;
  pointer-events: auto;
  overflow: hidden;
}

.v5-hero-overlay .v5-hero-title {
  color: #ffffff;
  text-shadow: 0 1px 14px rgba(0, 0, 0, 0.55);
  max-width: none;
  line-height: 1.25;
  margin: 0;
}

.v5-hero-overlay .v5-hero-sub {
  color: rgba(255, 255, 255, 0.96);
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.5);
  max-width: none;
  line-height: 1.4;
  margin: 0;
}

.v5-hero-overlay .v5-hero-status {
  flex-direction: column;
  align-items: flex-start;
  gap: 0.4rem;
  padding: 0;
  margin: 0;
  background: transparent;
  border: 0;
  color: rgba(255, 255, 255, 0.94);
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.45);
  backdrop-filter: none;
}

.v5-hero-overlay .v5-marker {
  font-size: inherit;
  padding: 0.08rem 0.25rem;
  line-height: 1.3;
}

.v5-hero-overlay .v5-hero-actions {
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem;
  margin-top: 0.5rem;
  flex-shrink: 0;
}

.v5-hero-overlay .v5-btn {
  padding: 0.75rem 1.05rem;
  white-space: normal;
  text-align: center;
  line-height: 1.25;
}

.v5-hero-overlay .v5-btn--ghost {
  color: #f5f5f5;
  border-color: rgba(255, 255, 255, 0.45);
  background: rgba(0, 0, 0, 0.25);
}

.v5-hero-overlay .v5-btn--ghost:hover {
  border-color: rgba(255, 255, 255, 0.7);
  color: #ffffff;
  background: rgba(0, 0, 0, 0.4);
}

.v5-hero-overlay .v5-btn--brief,
.v5-hero-overlay .v5-btn--budget {
  border-color: transparent;
}

.v5-hero-overlay .v5-btn--brief {
  color: var(--v5-brief-fg);
  background: var(--v5-brief);
}

.v5-hero-overlay .v5-btn--brief:hover {
  background: var(--v5-brief-hover);
  color: var(--v5-brief-fg);
}

.v5-hero-overlay .v5-btn--budget {
  color: var(--v5-accent-fg);
  background: var(--v5-accent);
}

.v5-hero-overlay .v5-btn--budget:hover {
  background: #d9ff5a;
  color: var(--v5-accent-fg);
}

.v5-hero-identity {
  display: inline-flex;
  align-items: center;
  gap: var(--v5-space-sm);
  padding: 0.4rem 0.75rem;
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
  border: 1px solid var(--v5-border-strong);
  border-radius: var(--v5-radius-sm);
  margin-bottom: var(--v5-space-lg);
}

.v5-hero-identity strong {
  color: var(--v5-fg);
  font-weight: 700;
}

.v5-hero-status {
  display: flex;
  flex-wrap: wrap;
  gap: var(--v5-space-md);
  padding: var(--v5-space-md) var(--v5-space-lg);
  margin-bottom: var(--v5-space-xl);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.08em;
  color: var(--v5-fg-muted);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
}

.v5-hero-status li {
  display: inline-flex;
  align-items: center;
  gap: var(--v5-space-xs);
}

.v5-hero-status .v5-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--v5-status-planned);
}

.v5-hero-status li[data-status="done"] .v5-dot {
  background: var(--v5-status-done);
}

.v5-hero-status li[data-status="active"] .v5-dot {
  background: var(--v5-status-active);
}

.v5-hero-title {
  font-size: clamp(2rem, 4.8vw, 3.5rem);
  margin-bottom: var(--v5-space-lg);
  max-width: 22ch;
}

.v5-hero-sub {
  font-size: var(--v5-text-lg);
  color: var(--v5-fg-muted);
  max-width: 55ch;
  margin-bottom: var(--v5-space-xl);
}

.v5-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--v5-space-md);
}

/* Hero overlay typography — scoped to copy panel, overrides generic .v5-hero-* */
.v5-hero-copy .v5-hero-status {
  flex-direction: column;
  align-items: flex-start;
  gap: 0.55rem;
  padding: 0;
  margin: 0 0 0.15rem;
  background: transparent;
  border: 0;
  font-family: var(--v5-font-mono);
  font-size: 0.9375rem;
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.96);
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.45);
}

.v5-hero-copy .v5-hero-status .v5-dot {
  width: 9px;
  height: 9px;
}

.v5-hero-copy .v5-hero-title {
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  line-height: 1.28;
  max-width: none;
  margin: 0;
  color: #ffffff;
  text-shadow: 0 1px 14px rgba(0, 0, 0, 0.55);
}

.v5-hero-copy .v5-hero-sub {
  font-size: clamp(1.05rem, 1.75vw, 1.3125rem);
  line-height: 1.45;
  max-width: none;
  margin: 0;
  color: rgba(255, 255, 255, 0.96);
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.5);
}

.v5-hero-copy .v5-hero-actions {
  gap: 0.65rem;
  margin-top: 0.35rem;
}

.v5-hero-copy .v5-btn {
  font-size: 0.9375rem;
  padding: 0.8rem 1.15rem;
}

.v5-hero-copy .v5-btn--ghost {
  color: #f5f5f5;
  border-color: rgba(255, 255, 255, 0.45);
  background: rgba(0, 0, 0, 0.25);
}

.v5-hero-copy .v5-btn--ghost:hover {
  border-color: rgba(255, 255, 255, 0.7);
  color: #ffffff;
  background: rgba(0, 0, 0, 0.4);
}

.v5-hero-copy .v5-btn--brief {
  color: var(--v5-brief-fg);
  background: var(--v5-brief);
  border-color: transparent;
}

.v5-hero-copy .v5-btn--brief:hover {
  background: var(--v5-brief-hover);
  color: var(--v5-brief-fg);
}

.v5-hero-copy .v5-btn--budget {
  color: var(--v5-accent-fg);
  background: var(--v5-accent);
  border-color: transparent;
}

.v5-hero-copy .v5-btn--budget:hover {
  background: #d9ff5a;
  color: var(--v5-accent-fg);
}

/* ---------- 7. SECTION 2 · What is BLACK WIDOW ---------- */

.v5-solution-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--v5-space-lg);
  margin-top: var(--v5-space-xl);
}

.v5-solution-card {
  padding: var(--v5-space-lg);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
}

.v5-solution-card h3 {
  font-size: var(--v5-text-lg);
  margin-bottom: var(--v5-space-sm);
}

.v5-solution-card p {
  color: var(--v5-fg-muted);
  font-size: var(--v5-text-sm);
}

/* ---------- 8. SECTION 3 · Engineering Evidence (Wall) ---------- */

.v5-evidence-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--v5-space-md);
  margin-bottom: var(--v5-space-xl);
}

.v5-evidence-header .v5-microcopy {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
}

.v5-evidence-wall {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-2xl);
}

.v5-evidence-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--v5-space-lg);
}

.v5-evidence-block__header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--v5-space-sm);
  padding-bottom: var(--v5-space-md);
  border-bottom: 1px solid var(--v5-border);
}

.v5-evidence-block__id {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-dim);
}

.v5-evidence-block__title {
  font-size: var(--v5-text-2xl);
  letter-spacing: 0.02em;
}

.v5-evidence-block__date {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  color: var(--v5-fg-muted);
  letter-spacing: 0.08em;
}

.v5-evidence-block__media {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--v5-space-md);
}

.v5-evidence-block__media[data-columns="2"] {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.v5-evidence-block__media[data-columns="3"] {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.v5-evidence-block__media .v5-photo-slot {
  aspect-ratio: 16 / 10;
}

.v5-evidence-block__media[data-columns="2"] .v5-photo-slot,
.v5-evidence-block__media[data-columns="3"] .v5-photo-slot {
  aspect-ratio: 4 / 3;
}

.v5-evidence-block__caption {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
  text-transform: uppercase;
}

.v5-evidence-footer {
  margin-top: var(--v5-space-2xl);
  padding-top: var(--v5-space-xl);
  border-top: 1px solid var(--v5-border);
  display: flex;
  justify-content: center;
}

/* ---------- 9. SECTION 4 · Why Phase I ---------- */

.v5-flow {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--v5-space-md);
  align-items: stretch;
  margin-block: var(--v5-space-xl);
}

.v5-flow-step {
  padding: var(--v5-space-lg);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
  position: relative;
}

.v5-flow-step[data-status="done"] {
  border-color: var(--v5-status-done);
}

.v5-flow-step[data-status="active"] {
  border-color: var(--v5-status-active);
}

.v5-flow-step__label {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
  margin-bottom: var(--v5-space-xs);
}

.v5-flow-step__title {
  font-size: var(--v5-text-lg);
  margin-bottom: var(--v5-space-xs);
}

.v5-flow-step__status {
  display: inline-block;
  margin-top: var(--v5-space-sm);
  padding: 0.15rem 0.5rem;
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  border-radius: var(--v5-radius-sm);
  color: var(--v5-fg-muted);
  border: 1px solid var(--v5-border-strong);
}

.v5-flow-step[data-status="done"] .v5-flow-step__status {
  color: var(--v5-status-done);
  border-color: var(--v5-status-done);
}

.v5-flow-step[data-status="active"] .v5-flow-step__status {
  color: var(--v5-status-active);
  border-color: var(--v5-status-active);
}

.v5-funding-scope {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--v5-space-md);
  margin-block: var(--v5-space-xl);
}

.v5-funding-scope li {
  padding: var(--v5-space-md);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
  color: var(--v5-fg-muted);
  font-size: var(--v5-text-sm);
}

.v5-budget {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--v5-space-md);
  padding: var(--v5-space-lg);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
}

.v5-budget__label {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
}

.v5-budget__value {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-2xl);
  font-weight: 700;
  color: var(--v5-accent);
}

/* ---------- 10. SECTION 5 · Research Program (cards) ---------- */

.v5-research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--v5-space-lg);
  margin-block: var(--v5-space-xl);
}

.v5-research-card {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-md);
  padding: var(--v5-space-lg);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
}

.v5-research-card__num {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-dim);
}

.v5-research-card__title {
  font-size: var(--v5-text-xl);
}

.v5-research-card__field-label {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
  margin-bottom: var(--v5-space-2xs);
}

.v5-research-card__field-value {
  font-size: var(--v5-text-sm);
  color: var(--v5-fg);
}

/* ---------- 11. SECTION 6 · Deliverables ---------- */

.v5-deliverables {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--v5-space-lg);
  margin-top: var(--v5-space-xl);
}

.v5-deliverable {
  padding: var(--v5-space-lg);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
  background: var(--v5-bg-panel);
}

.v5-deliverable h3 {
  font-size: var(--v5-text-lg);
  margin-bottom: var(--v5-space-sm);
}

.v5-deliverable p {
  color: var(--v5-fg-muted);
  font-size: var(--v5-text-sm);
}

/* ---------- 12. SECTION 7 · Documents ---------- */

.v5-docs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--v5-space-lg);
  margin-top: var(--v5-space-xl);
}

.v5-doc {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-md);
  padding: var(--v5-space-lg);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
}

.v5-doc__meta {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-dim);
}

.v5-doc__title {
  font-size: var(--v5-text-lg);
}

.v5-doc__desc {
  font-size: var(--v5-text-sm);
  color: var(--v5-fg-muted);
  flex: 1;
}

/* ---------- 10b. Validated Technologies grid ----------
   Portfolio of aerospace research programs validated through the platform.
   No commercial-product framing. No person-level attribution.
*/

.v5-tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--v5-space-lg);
  margin-block: var(--v5-space-xl);
}

.v5-tech-card {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-sm);
  padding: var(--v5-space-lg);
  background: var(--v5-bg-panel);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
  overflow: hidden;
}

.v5-tech-card__media {
  position: relative;
  margin: calc(-1 * var(--v5-space-lg)) calc(-1 * var(--v5-space-lg)) var(--v5-space-xs);
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--v5-bg-panel-2, #0f141b);
  border-bottom: 1px solid var(--v5-border);
}

.v5-tech-card__media img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Section-hero figure — for Research Platform (§2) and Validated
   Technologies (§3). Sits below the section header, before the grid. */
.v5-section-hero {
  position: relative;
  margin: var(--v5-space-xl) 0;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border-radius: var(--v5-radius-md);
  background: #ffffff;
  border: 1px solid var(--v5-border);
}

.v5-section-hero img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.v5-tech-card--reserved {
  border-style: dashed;
  background: transparent;
}

.v5-tech-card__label {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-dim);
}

.v5-tech-card__title {
  font-size: var(--v5-text-xl);
}

.v5-tech-card__role {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.08em;
  color: var(--v5-fg-muted);
  text-transform: uppercase;
}

.v5-tech-card__desc {
  font-size: var(--v5-text-sm);
  color: var(--v5-fg-muted);
}

/* ---------- 12b. Documents · gated tier (grant reviewers) ---------- */

.v5-doc--gated {
  border-style: dashed;
  border-color: var(--v5-border-strong);
  background: transparent;
}

.v5-doc__tier {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  border-radius: var(--v5-radius-sm);
  color: var(--v5-fg-dim);
  border: 1px solid var(--v5-border-strong);
  margin-bottom: var(--v5-space-xs);
}

.v5-doc--gated .v5-doc__tier {
  color: var(--v5-status-active);
  border-color: var(--v5-status-active);
}

/* ---------- 13. SECTION Contact ---------- */

.v5-legal-block {
  padding: var(--v5-space-lg);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
  background: var(--v5-bg-panel);
  margin-block: var(--v5-space-xl);
}

.v5-legal-block dl {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: var(--v5-space-sm) var(--v5-space-lg);
  font-size: var(--v5-text-sm);
  margin: 0;
}

.v5-legal-block dt {
  color: var(--v5-fg-muted);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.v5-legal-block dd {
  margin: 0;
  color: var(--v5-fg);
  font-family: var(--v5-font-mono);
}

.v5-contact {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-md);
  padding: var(--v5-space-lg);
  border: 1px solid var(--v5-border);
  border-radius: var(--v5-radius-md);
  background: var(--v5-bg-panel);
}

.v5-contact a {
  color: var(--v5-accent);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-lg);
}

/* ---------- 14. Footer ---------- */

.v5-footer {
  padding-block: var(--v5-space-2xl);
  background: var(--v5-bg-elev);
  border-top: 1px solid var(--v5-border);
  font-size: var(--v5-text-sm);
  color: var(--v5-fg-muted);
}

.v5-footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: var(--v5-space-2xl);
}

.v5-secondary-nav {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-sm);
}

.v5-secondary-nav h4 {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
  text-transform: uppercase;
  margin-bottom: var(--v5-space-sm);
}

.v5-secondary-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: var(--v5-space-md);
}

.v5-secondary-nav a {
  font-size: var(--v5-text-sm);
  color: var(--v5-fg-muted);
  padding-block: var(--v5-space-2xs);
  border-bottom: 1px dashed transparent;
}

.v5-secondary-nav a:hover {
  color: var(--v5-fg);
  border-bottom-color: var(--v5-fg-muted);
}

.v5-disclosures h4 {
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  letter-spacing: 0.14em;
  color: var(--v5-fg-muted);
  text-transform: uppercase;
  margin-bottom: var(--v5-space-sm);
}

.v5-disclosures ul {
  display: flex;
  flex-direction: column;
  gap: var(--v5-space-xs);
}

.v5-disclosures li {
  padding-inline-start: 1rem;
  position: relative;
  font-size: var(--v5-text-xs);
  color: var(--v5-fg-muted);
  line-height: 1.5;
}

.v5-disclosures li::before {
  content: "·";
  position: absolute;
  left: 0;
  color: var(--v5-fg-dim);
}

.v5-footer-meta {
  margin-top: var(--v5-space-xl);
  padding-top: var(--v5-space-lg);
  border-top: 1px solid var(--v5-border);
  font-family: var(--v5-font-mono);
  font-size: var(--v5-text-xs);
  color: var(--v5-fg-dim);
  letter-spacing: 0.08em;
}

/* ---------- 15. Responsive ---------- */

@media (max-width: 960px) {
  .v5-solution-grid,
  .v5-flow {
    grid-template-columns: 1fr;
  }

  .v5-footer-inner {
    grid-template-columns: 1fr;
  }
}

/* Hero: stacked layout on narrow viewports (overlay is unreadable below ~900px) */
@media (max-width: 900px) {
  .v5-hero-stage {
    display: flex;
    flex-direction: column;
  }

  .v5-hero-stage::before {
    display: none;
  }

  .v5-hero-visual .v5-photo-slot {
    aspect-ratio: 16 / 10;
    max-height: min(46vh, 320px);
  }

  .v5-hero-visual .v5-photo-slot img {
    object-position: center 35%;
  }

  .v5-hero-overlay {
    position: static;
    inset: auto;
    pointer-events: auto;
  }

  .v5-hero-copy {
    position: static;
    width: 100%;
    max-width: none;
    padding: var(--v5-space-lg) clamp(1rem, 4vw, 1.5rem) var(--v5-space-xl);
    overflow: visible;
    gap: var(--v5-space-md);
    justify-content: flex-start;
    background: var(--v5-bg-elev);
    border-top: 1px solid var(--v5-border);
  }

  .v5-hero-copy .v5-hero-status {
    font-size: var(--v5-text-xs);
    gap: var(--v5-space-sm);
    letter-spacing: 0.05em;
    color: var(--v5-fg);
    text-shadow: none;
  }

  .v5-hero-copy .v5-hero-status li {
    display: flex;
    align-items: flex-start;
    line-height: 1.45;
    max-width: 100%;
    overflow-wrap: anywhere;
  }

  .v5-hero-copy .v5-hero-title {
    font-size: clamp(1.15rem, 4.8vw, 1.5rem);
    line-height: 1.35;
    color: var(--v5-fg);
  }

  .v5-hero-copy .v5-hero-sub {
    font-size: var(--v5-text-base);
    line-height: 1.5;
    color: var(--v5-fg-muted);
    text-shadow: none;
  }

  .v5-hero-copy .v5-hero-actions {
    flex-direction: column;
    align-items: stretch;
    gap: var(--v5-space-sm);
    margin-top: var(--v5-space-sm);
  }

  .v5-hero-copy .v5-btn {
    width: 100%;
    font-size: var(--v5-text-sm);
    padding: 0.85rem 1rem;
  }

  .v5-hero-copy .v5-btn--ghost {
    color: var(--v5-fg);
    border-color: var(--v5-border-strong);
    background: transparent;
  }

  .v5-hero-copy .v5-btn--ghost:hover {
    color: var(--v5-accent);
    border-color: var(--v5-accent);
    background: rgba(201, 255, 58, 0.06);
  }
}

@media (max-width: 720px) {
  .v5-nav {
    display: none;
    position: absolute;
    inset-inline: 0;
    top: 100%;
    padding: var(--v5-space-md) clamp(1rem, 4vw, 2rem);
    background: var(--v5-bg-elev);
    border-bottom: 1px solid var(--v5-border);
  }

  .v5-nav.is-open {
    display: block;
  }

  .v5-nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--v5-space-md);
  }

  .v5-nav-toggle {
    display: inline-flex;
    margin-inline-start: auto;
  }

  .v5-section {
    padding-block: var(--v5-space-2xl);
  }

  .v5-hero-status {
    flex-direction: column;
    align-items: flex-start;
  }

  .v5-evidence-block__media[data-columns="2"],
  .v5-evidence-block__media[data-columns="3"] {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition: none !important;
    animation: none !important;
  }
}

/* ---------- 16. Print ---------- */

@media print {
  .v5-header,
  .v5-footer,
  .v5-hero-actions,
  .v5-btn {
    display: none;
  }

  body {
    background: #fff;
    color: #000;
  }
}